query: the ovum gets implanted in uterus after how many days post fertilization with sperm

pos: Implantation (human embryo) Implantation (human embryo) In humans, implantation is the stage of pregnancy at which the embryo adheres to the wall of the uterus. At this stage of prenatal development, the conceptus is called a blastocyst. It is by this adhesion that the embryo receives oxygen and nutrients from the mother to be able to grow. In humans, implantation of a fertilized ovum is most likely to occur around 9 days after ovulation, however this can range between 6 and 12 days. The reception-ready phase of the endometrium of the uterus is usually termed the "implantation window" and lasts about 4 days.

neg: Human sexuality then travels for three to four days to the uterus. After sexual intercourse, sperm swim up this funnel from the uterus. The lining of the tube and its secretions sustain the egg and the sperm, encouraging fertilization and nourishing the ovum until it reaches the uterus. If the ovum divides after fertilization, identical twins are produced. If separate eggs are fertilized by different sperm, the mother gives birth to non-identical or fraternal twins. The ovaries are the female gonads; they develop from the same embryonic tissue as the testicles. The ovaries are suspended by ligaments and are the source where

neg: Sexual intercourse competition). When a fertile ovum from the female is present in the fallopian tubes, the male gamete joins with the ovum, resulting in fertilization and the formation of a new embryo. When a fertilized ovum reaches the uterus, it becomes implanted in the lining of the uterus (the endometrium) and a pregnancy begins. Pregnancy rates for sexual intercourse are highest during the menstrual cycle time from some 5 days before until 1 to 2 days after ovulation. For optimal pregnancy chance, there are recommendations of sexual intercourse every 1 or 2 days, or every 2 or 3 days. Studies have

neg: Prenatal development body of the uterus and into the Fallopian tubes. Fertilization of the egg cell (ovum), usually takes place in one of the Fallopian tubes. Many sperm are released with the possibility of just one sperm cell managing to adhere to and enter the thick protective shell-like layer surrounding the ovum. The first sperm that penetrates fully into the egg donates its genetic material (DNA). The egg then polarizes, repelling any additional sperm. The resulting combination is called a zygote, a new and genetically unique organism. The term "conception" refers variably to either fertilization or to formation of the conceptus after

neg: Human reproductive system Human reproductive system The human reproductive system usually involves internal fertilization by sexual intercourse. In this process, the male inserts his penis into the female's vagina and ejaculates semen, which contains sperm. A small proportion of the sperm pass through the cervix into the uterus, and then into the Fallopian tubes for fertilization of the ovum. Only one sperm is required to fertilize the ovum. Upon successful fertilization, the fertilized ovum, or zygote, travels out of the Fallopian tube and into the uterus, where it implants in the uterine wall. This marks the beginning of gestation, better known as pregnancy,

neg: Reproductive system stimulates some of the ova to develop and grow. One ovum is released and it passes through the fallopian tube into the uterus. Hormones produced by the ovaries prepare the uterus to receive the ovum. It sita her and awaits the sperm for fertilization to occur. When this does not occur i.e. no sperm for fertilization, the lining of the uterus, called the endometrium, and unfertilized ova are shed each cycle through the process of menstruation. If the ovum is fertilized by sperm, it attaches to the endometrium and the fetus develops. Most mammal reproductive systems are similar, however, there

neg: Blastocyst vivo" fertilization for fertilizing an egg with sperm and implanting that embryo into a female’s womb. For many years the embryo was inserted into the uterus two to three days after fertilization. However at this stage of development it is very difficult to predict which embryos will develop best, and several embryos were typically implanted. Several implanted embryos increased the likelihood of a developing fetus but also led to the development of multiple fetuses. This was a major problem and drawback for using embryos to IVF. A recent breakthrough for "in vitro" fertilization is the use of blastocysts. A blastocyst

neg: Mammalian reproduction produce the female's ova. All of these parts are always internal. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the Fallopian tubes. At certain intervals, the ovaries release an ovum, which passes through the fallopian tube into the uterus. If, in this transit, it meets with sperm, the egg selects sperm with which to merge; this is termed fertilization. The fertilization usually occurs in the oviducts, but can happen in the uterus itself. The zygote then implants itself in the wall of the uterus, where it begins the processes

neg: Human operate on human populations, with evidence that certain regions of the genome display directional selection in the past 15,000 years. As with other mammals, human reproduction takes place as internal fertilization by sexual intercourse. During this process, the male inserts his erect penis into the female's vagina and ejaculates semen, which contains sperm. The sperm travels through the vagina and cervix into the uterus or Fallopian tubes for fertilization of the ovum. Upon fertilization and implantation, gestation then occurs within the female's uterus. The zygote divides inside the female's uterus to become an embryo, which over a period of 38

neg: Childlessness sperm injection is a more recent technique that involves injecting a single sperm directly into an egg, the egg is then placed in the uterus by in vitro fertilization. In vitro fertilization (IVF) is the process in which a mature ovum is surgically removed from a women's ovary, placed in a medium with sperm until fertilization occurs and then placed in the women's uterus. About 50,000 babies in the United States are conceived this way and are sometimes referred to as "test-tube babies." Other forms of assisted reproductive technology include, gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT). Fertility

neg: Reproductive system sometimes to a unique pore such as a vagina or intromittent organ. The human reproductive system usually involves internal fertilization by sexual intercourse. During this process, the male inserts his erect penis into the female's vagina and ejaculates semen, which contains sperm. The sperm then travels through the vagina and cervix into the uterus or fallopian tubes for fertilization of the ovum. Upon successful fertilization and implantation, gestation of the fetus then occurs within the female's uterus for approximately nine months, this process is known as pregnancy in humans. Gestation ends with birth, the process of birth is known as

neg: Fertility preservation cryopreserved ovarian tissue could possibly be used to make oocytes that can directly undergo in vitro fertilization. Many patients diagnosed with a malignancy or another disease requiring treatment that may impair their fertility consider alternatives to bearing biological children, such as assisted reproductive technology (ART) using in vitro fertilization (IVF) with donor eggs or donor sperm. The resulting embryo can be implanted into the woman's uterus after her endometrium (the lining of the uterus) is stimulated with hormones to prepare for the development of the embryo. In women requiring local pelvic radiation therapy may benefit from surgical transposition of the

neg: Human reproductive system Examples of unclassifiable disorders are Peyronie's disease in males and endometriosis in females. Many congenital conditions cause reproductive abnormalities, but are better known for their other symptoms. These include: Turner syndrome, Klinefelter's syndrome, Cystic fibrosis, and Bloom syndrome. Human reproductive system The human reproductive system usually involves internal fertilization by sexual intercourse. In this process, the male inserts his penis into the female's vagina and ejaculates semen, which contains sperm. A small proportion of the sperm pass through the cervix into the uterus, and then into the Fallopian tubes for fertilization of the ovum. Only one sperm is required to

neg: In vitro fertilisation In vitro fertilisation In vitro fertilisation (IVF) is a process of fertilisation where an egg is combined with sperm outside the body, in vitro ("in glass"). The process involves monitoring and stimulating a woman's ovulatory process, removing an ovum or ova (egg or eggs) from the woman's ovaries and letting sperm fertilise them in a liquid in a laboratory. After the fertilised egg (zygote) undergoes embryo culture for 2–6 days, it is implanted in the same or another woman's uterus, with the intention of establishing a successful pregnancy. IVF is a type of assisted reproductive technology used for infertility treatment

neg: Immunocontraception it as a possible immunocontraceptive vector. In placental mammals, fertilization typically occurs inside the female in the oviducts. The oviducts are positioned near the ovaries where ova are produced. An ovum therefore needs only to travel a short distance to the oviducts for fertilization. In contrast sperm cells must be highly motile, since they are deposited into the female reproductive tract during sexual intercourse and must travel through the cervix (in some species) as well as the uterus and the oviduct (in all species) to reach an ovum. Sperm cells that are motile are spermatozoa. Spermatozoa are protected from the

neg: Human reproduction love". The sperm and the ovum are known as gametes (each containing half the genetic information of the parent, created through meiosis). The sperm (being one of approximately 250 million sperm in a typical male ejaculation) travels through the vagina and cervix into the uterus or Fallopian tubes. Only 1 in 14 million of the ejaculated sperm will reach the Fallopian tube. The egg simultaneously moves through the Fallopian tube away from the ovary. One of the sperm encounters, penetrates and fertilizes the ovum, creating a zygote. Upon fertilization and implantation, gestation of the fetus then occurs within the female's

neg: Female reproductive system ova (egg cells). The external sex organs are also known as the "genitals" and these are the organs of the vulva including the labia, clitoris, and vaginal opening. The vagina is connected to the uterus at the cervix. At certain intervals, the ovaries release an ovum, which passes through the Fallopian tube into the uterus. If, in this transit, it meets with sperm, a single sperm can enter and merge with the egg, fertilizing it. Fertilization usually occurs in the Fallopian tubes and marks the beginning of embryogenesis. The zygote will then divide over enough generations of cells to form

neg: Common Time "beademung" was like or even if it was real, but he has a haunting sense of loss. In "In Search of Wonder", Damon Knight argues that the story is a symbolic representation of fertilization of a female ovum by a sperm, and that the protagonist Garrard is the sperm. The Earth represents the testes; Alpha Centauri is the uterus; and the beademung is the ovum. Furthermore, Knight argues, the first part of the story, which contains all the intercourse symbolism, is told backwards. Even the title, Knight argues, is an unintentiontial pun for "Come on time". James Blish (quoted by

neg: Fallopian tube of meiosis II. This secondary oocyte is then ovulated. The follicle and the ovary's wall rupture, allowing the secondary oocyte to escape. The secondary oocyte is caught by the fimbriated end and travels to the ampulla of the uterine tube where typically the sperm are met and fertilization occurs; meiosis II is promptly completed. The fertilized ovum, now a zygote, travels towards the uterus aided by activity of tubal cilia and activity of the tubal muscle. The early embryo requires critical development in the fallopian tube. After about five days the new embryo enters the uterine cavity and on about

neg: Uterus transplantation ovum and her husband's sperm, which was then implanted into the transplanted uterus. The uterus may have been damaged in the course of the caesarian delivery and it may or may not be suitable for future pregnancies. A regimen of triple immuno-suppression was used with tacrolimus, azathioprine, and corticosteroids. Three mild rejection episodes occurred, one during the pregnancy, but were all successfully suppressed with medication. Some other women were also reported to be pregnant at that time using transplanted uteri. The unnamed mother, who received a donated womb from a friend, said that she hoped the treatment would be refined

neg: Human sexuality causes a Graafian follicle to surface the ovary. The follicle ruptures and the ripe ovum is expelled into the abdominal cavity. The fallopian tubes pick up the ovum with the fimbria. The cervical mucus changes to aid the movement of sperm. On days 15 to 28—the post-ovulatory stage, the Graafian follicle—now called the corpus luteum—secretes estrogen. Production of progesterone increases, inhibiting LH release. The endometrium thickens to prepare for implantation, and the ovum travels down the Fallopian tubes to the uterus. If the ovum is not fertilized and does not implant, menstruation begins. The sexual response cycle is a model

neg: Hamster zona-free ovum test whose sperm fail the hamster test are a third as fertile than those whose sperm pass. Donated sperm and intracytoplasmic sperm injection techniques are considered more strongly for those whose sperm fail this test. Contrary to some assertions by medical professionals, if the human sperm penetrates the hamster egg, a hybrid embryo is indeed created. The resulting hamster-hybrid is known as a humster. These embryos are typically destroyed before they divide into two cells and are never known to have been implanted in either a hamster or human uterus to develop. This test evaluates the acrosome reaction of human spermatozoa.

neg: Human reproductive system Approximately every 28 days, the pituitary gland releases a hormone that stimulates some of the ova to develop and grow. One ovum is released and it passes through the Fallopian tube into the uterus. Hormones produced by the ovaries prepare the uterus to receive the ovum. The lining of the uterus, called the endometrium, and unfertilized ova are shed each cycle through the process of menstruation. If the ovum is fertilized by sperm, it attaches to the endometrium and the fetus develops. The development of the reproductive system and the development of the urinary system are closely tied in with

neg: Prenatal development its implantation in the uterus, and this terminology is controversial. Prior to fertilization, each ovum, as a gamete, contains half of the genetic material that will fuse with the male gamete, which carries the other half of the genetic material (DNA). The ovum only carries the X female sex chromosome whilst the sperm carries a single sex chromosome of either an X or a male Y chromosome. The resulting human zygote is similar to the majority of somatic cells because it contains two copies of the genome in a diploid set of chromosomes. One set of chromosomes came from the

neg: Human reproduction a sperm may penetrate and merge with the egg, fertilizing it with the help of certain hydrolytic enzymes present in the acrosome. The fertilization usually occurs in the oviducts, but can happen in the uterus itself. The zygote then becomes implanted in the lining of the uterus, where it begins the processes of embryogenesis and morphogenesis. When the fetus is developed enough to survive outside of the uterus, the cervix dilates and contractions of the uterus propel it through the birth canal, which is the vagina. The ova, which are the female sex cells, are much larger than the spermatozoon

neg: Sex selection the father's sperm in a technique called in vitro fertilization (IVF). "In vitro" is Latin for "within glass". Fertilized eggs are called embryos. As the embryos develop through mitosis, they are separated by sex. Embryos of the desired gender are implanted back in the mother's uterus. Prior to fertilization with IVF, the fertilized eggs can be genetically biopsied with preimplantation genetic diagnosis (PGD) to increase fertilization success. Once an embryo grows to a 6-8 cell size, a small laser incision in the egg membrane (zona pellucida) allows safe removal of one of the cells. Every cell in the embryo contains

neg: Human sexuality about 20% of women it tilts backwards. The uterus has three layers; the innermost layer is the endometrium, where the egg is implanted. During ovulation, this thickens for implantation. If implantation does not occur, it is sloughed off during menstruation. The cervix is the narrow end of the uterus. The broad part of the uterus is the fundus. During ovulation, the ovum travels down the Fallopian tubes to the uterus. These extend about from both sides of the uterus. Finger-like projections at the ends of the tubes brush the ovaries and receive the ovum once it is released. The ovum

neg: Human fertilization Human fertilization Human fertilization is the union of a human egg and sperm, usually occurring in the ampulla of the fallopian tube. The result of this union is the production of a zygote cell, or fertilized egg, initiating prenatal development. Scientists discovered the dynamics of human fertilization in the nineteenth century. The process of fertilization involves a sperm fusing with an ovum. The most common sequence begins with ejaculation during copulation, follows with ovulation, and finishes with fertilization. Various exceptions to this sequence are possible, including artificial insemination, "in vitro" fertilization, external ejaculation without copulation, or copulation shortly after ovulation.

neg: Pregnancy (mammals) Pregnancy (mammals) In mammals, pregnancy is the period of reproduction during which a female carries one or more live offspring from implantation in the uterus through gestation. It begins when a fertilized zygote implants in the female's uterus, and ends once it leaves the uterus. During copulation, the male inseminates the female. The spermatozoon fertilizes an ovum or various ova in the uterus or fallopian tubes, and this results in one or multiple zygotes. Sometimes, a zygote can be created by humans outside of the animal's body in the artificial process of in-vitro fertilization. After fertilization, the newly formed zygote

neg: Human fertilization takes place, preventing other sperm from fertilizing the same egg. The oocyte now undergoes its second meiotic division producing the haploid ovum and releasing a polar body. The sperm nucleus then fuses with the ovum, enabling fusion of their genetic material. The fusion of cell membranes of the secondary oocyte and sperm takes place. In preparation for the fusion of their genetic material both the oocyte and the sperm undergo transformations as a reaction to the fusion of cell membranes. The oocyte completes its second meiotic division. This results in a mature ovum. The nucleus of the oocyte is called

neg: Ovulation of transformations called cumulus expansion, which is stimulated by FSH. After this is done, a hole called the stigma will form in the follicle, and the secondary oocyte will leave the follicle through this hole. Ovulation is triggered by a spike in the amount of FSH and LH released from the pituitary gland. During the luteal (post-ovulatory) phase, the secondary oocyte will travel through the fallopian tubes toward the uterus. If fertilized by a sperm, the fertilized secondary oocyte or ovum may implant there 6–12 days later. The follicular phase (or proliferative phase) is the phase of the menstrual cycle

neg: Surrogacy Paragraph 2376 of the Catechism of the Catholic Church states that: "Techniques that entail the dissociation of husband and wife, by the intrusion of a person other than the couple (donation of sperm or ovum, surrogate uterus), are gravely immoral." Jewish legal scholars debate this issue. Some contend that parenthood is determined by the woman giving birth while others opt to consider the genetic parents the legal parents. Some Jewish religious establishments have accepted surrogacy only if it is full gestational surrogacy with both intended parents' gametes included and fertilization done via IVF. Hindu scholars have not debated the issue.

neg: Human fertilization fertilization process. Human fertilization Human fertilization is the union of a human egg and sperm, usually occurring in the ampulla of the fallopian tube. The result of this union is the production of a zygote cell, or fertilized egg, initiating prenatal development. Scientists discovered the dynamics of human fertilization in the nineteenth century. The process of fertilization involves a sperm fusing with an ovum. The most common sequence begins with ejaculation during copulation, follows with ovulation, and finishes with fertilization. Various exceptions to this sequence are possible, including artificial insemination, "in vitro" fertilization, external ejaculation without copulation, or copulation shortly

neg: Female reproductive system the fetus at the time of birth. The uterus contains three suspensory ligaments that help stabilize the position of the uterus and limits its range of movement. The uterosacral ligaments keep the body from moving inferiorly and anteriorly. The round ligaments restrict posterior movement of the uterus. The cardinal ligaments also prevent the inferior movement of the uterus. The uterus is a pear-shaped muscular organ. Its major function is to accept a fertilized ovum which becomes implanted into the endometrium, and derives nourishment from blood vessels which develop exclusively for this purpose. The fertilized ovum becomes an embryo, develops into

neg: Immunocontraception is the ovum and is produced by females of the species. Under this scheme, fertilization requires two gametes, one from an individual of each sex, in order to occur. Immunocontraception targeting the female gamete has focused on the zona pellucida. Immunocontraception targeting the male gamete has involved many different antigens associated with sperm function. The zona pellucida is a glycoprotein membrane surrounding the plasma membrane of an ovum. The zona pellucida's main function in reproduction is to bind sperm. Immunity against zonae pellucidae causes an animal to produce antibodies that themselves are bound by a zona pellucida. Thus when a

neg: Beginning of human personhood ovum and the haploid sperm, you get the diploid embryo. And at that point, something happens that is totally different, because the thing that's there seems totally different. One objection raised to the fertilization view is that not all of the objects created by the union of a sperm and an egg are human beings. Objects such as hydatidiform moles, choriocarcinomas, and blighted ovums are clearly not. Neither will every normal zygote develop into an adult. There are many fertilized eggs that never implant and are "simply washed away" after fertilization, though this can be answered by the fact that

neg: Drosophila melanogaster second male sperm becomes significant 2–7 days after copulation. The seminal fluid of the second male is believed to be responsible for this incapacitation mechanism (without removal of first male sperm) which takes effect before fertilization occurs. The delay in effectiveness of the incapacitation mechanism is believed to be a protective mechanism that prevents a male fly from incapacitating his own sperm should he mate with the same female fly repetitively. Sensory neurons in the uterus of female "D. melanogaster" respond to a male protein, sex peptide, which is found in sperm. This protein makes the female reluctant to copulate

neg: Embryo transfer eggs but a uterus may utilize egg donor IVF, in which case another woman would provide eggs for fertilization and the resulting embryos are placed into the uterus of the patient. Fertilization may be performed using the woman's partner's sperm or by using donor sperm. 'Spare' embryos which are created for another couple undergoing IVF treatment but which are then surplus to that couple's needs may also be transferred (called embryo donation). Embryos may be specifically created by using eggs and sperm from donors and these can then be transferred into the uterus of another woman. A surrogate may carry

neg: Beginning of human personhood believed that Aristotle had been proven correct. Some observers believed they could see an entirely pre-formed little human body in the head of a sperm. The human ova was first observed in 1827 by Karl Ernst von Baer. Only in 1876 did Oscar Hertwig prove that fertilization is due to fusion of an egg and sperm cell. Many members of the medical community accept fertilization as the point at which life begins. Dr. Bradley M. Patten from the University of Michigan wrote in "Human Embryology" that the union of the sperm and the ovum "initiates the life of a new

neg: Fertilisation membrane. The sperm surface protein bindin, binds to a receptor on the vitelline membrane identified as EBR1. Fusion of the plasma membranes of the sperm and egg are likely mediated by bindin. At the site of contact, fusion causes the formation of a fertilisation cone. Mammals internally fertilise through copulation. After a male ejaculates, many sperm move to the upper vagina (via contractions from the vagina) through the cervix and across the length of the uterus to meet the ovum. In cases where fertilisation occurs, the female usually ovulates during a period that extends from hours before copulation to a

neg: Human embryogenesis of development; at the beginning of the ninth week the embryo is termed a fetus. Human embryology is the study of this development during the first eight weeks after fertilisation. The normal period of gestation (pregnancy) is nine months or 38 weeks. The germinal stage refers to the time from fertilization through the development of the early embryo until implantation is completed in the uterus. The germinal stage takes around 10 days. During this stage, the zygote begins to divide, in a process called cleavage. A blastocyst is then formed and implanted in the uterus. Embryogenesis continues with the next

neg: Oocyte activation Oocyte activation Oocyte (or ovum/egg) activation is a series of processes that occur in the oocyte during fertilization. Sperm entry causes calcium release into the oocyte. In mammals, this has been proposed to be caused by the introduction of phospholipase C isoform zeta (PLCζ) from the sperm cytoplasm, although this remains to be established definitively. Activation of the ovum includes the following events: The sperm may trigger egg activation via the interaction between a sperm protein and an egg surface receptor. Izumo is the sperm cell signal, that will trigger the egg receptor Juno. This receptor is activated by the

neg: Immunocontraception sperm encounters an ovum in an animal immunized against zonae pellucidae, the sperm cannot bind to the ovum because its zona pellucida has already been occupied by antibodies. Therefore, fertilization does not occur. Work begun by researchers at the University of Tennessee in the 1970s into immunity against zonae pellucidae resulted in its identification as a target antigen for immunocontraception. The zona pellucida's suitability is a result of it being necessary for fertilization and containing at least one antigen that is tissue-specific and not species-specific. The tissue-specificity implies that immunity against zonae pellucidae will not also affect other tissues in

neg: Mammalian reproduction mutation rate in male germinal tissue. Sperm are the smaller of the two gametes and are generally very short-lived, requiring males to produce them continuously from the time of sexual maturity until death. The produced sperm are stored in the epididymis until ejaculation. The sperm cells are motile and they swim using tail-like flagella to propel themselves towards the ovum. The sperm follows temperature gradients (thermotaxis) and chemical gradients (chemotaxis) to locate the ovum. The mammalian female reproductive system likewise contains two main divisions: the vagina and uterus, which act as the receptacle for the sperm, and the ovaries, which

neg: Reproduction from heterosis. This may be an indication that the sexual reproduction has advantages other than heterosis, such as genetic recombination between members of the species, allowing the expression of a wider range of traits and thus making the population more able to survive environmental variation. Allogamy is the fertilization of the combination of gametes from two parents, generally the ovum from one individual with the spermatozoa of another. (In isogamous species, the two gametes will not be defined as either sperm or ovum.) Self-fertilization, also known as autogamy, occurs in hermaphroditic organisms where the two gametes fused in fertilization come

neg: Miscarriage other tissues do. This has been called a "blighted ovum". Successful implantation of the zygote into the uterus is most likely 8 to 10 days after conception. If the zygote has not implanted by day 10, implantation becomes increasingly unlikely in subsequent days. A chemical pregnancy is a pregnancy that was detected by testing but ends in miscarriage before or around the time of the next expected period. Chromosomal abnormalities are found in more than half of embryos miscarried in the first 13 weeks. Half of embryonic miscarriages (25% of all miscarriages) have an aneuploidy (abnormal number of chromosomes). Common

neg: Human fertilization Upon encountering the secondary oocyte, the acrosome of the sperm produces enzymes which allow it to burrow through the outer jelly coat of the egg. The sperm plasma, then fuses with the egg's plasma membrane, the sperm head disconnects from its flagellum and the egg travels down the Fallopian tube to reach the uterus. In vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the womb, "in vitro". The sperm binds through the corona radiata, a layer of follicle cells on the outside of the secondary oocyte. Fertilization occurs when the nucleus of both

neg: Fetal pig tissue and organ development. Within hours of mating, the sperm and egg undergo fertilization in the oviduct and three days later the egg moves into the uterus. The cells begin to specialize by day six, and attach themselves to the uterus lining by day eleven. From fertilization to day 18, the endoderm, ectoderm and mesoderm have been forming inside the embryo, and are completely formed by day 18, the same day the placenta forms. The endoderm transforms into the lungs, trachea, thyroid gland, and digestive tract of the fetus. The ectoderm has a greater role in the development of the

neg: Acanthocephala a penis which opens posteriorly. In the female, the ovaries are found, like the testes, as rounded bodies along the ligament. From the ovaries, masses of ova dehisce into the body cavity, floating in its fluids for fertilization by male's sperm. After fertilization, each egg contains a developing embryo. (These embryos hatch into first stage larva.) The fertilized eggs are brought into the uterus by actions of the "uterine bell", a funnel like opening continuous with the uterus. At the junction of the bell and the uterus there is a second, smaller opening situated dorsally. The bell "swallows" the matured

neg: Oocyte activation (ICSI) cycles. Another of method is by using the drug Roscovitine, this reduces the activity of M-phase promoting factor activity in mice. Oocyte activation Oocyte (or ovum/egg) activation is a series of processes that occur in the oocyte during fertilization. Sperm entry causes calcium release into the oocyte. In mammals, this has been proposed to be caused by the introduction of phospholipase C isoform zeta (PLCζ) from the sperm cytoplasm, although this remains to be established definitively. Activation of the ovum includes the following events: The sperm may trigger egg activation via the interaction between a sperm protein and an

neg: Pregnancy lining of the uterus. This is about a week to ten days after fertilization. In this model, during the time between conception and implantation, the future fetus exists, but the woman is not considered pregnant. The sperm and the egg cell, which has been released from one of the female's two ovaries, unite in one of the two fallopian tubes. The fertilized egg, known as a zygote, then moves toward the uterus, a journey that can take up to a week to complete. Cell division begins approximately 24 to 36 hours after the male and female cells unite. Cell division

neg: Pronucleus of chromosomes. The appearance of two pronuclei is the first sign of successful fertilization as observed during in vitro fertilisation, and is usually observed 18 hours after insemination or ICSI. The zygote is then termed a "two-pronuclear zygote" (2PN). Two-pronuclear zygotes transitioning through 1PN or 3PN states tend to develop into poorer-quality embryos than ones who remain 2PN throughout development, and may be significant in embryo selection in IVF. Pronucleus A pronucleus (plural: pronuclei) is the nucleus of a sperm or an egg cell during the process of fertilization, after the sperm enters the ovum, but before the genetic material

neg: Prenatal development nucleus of the ovum and the second set from the nucleus of the sperm. The zygote is male if the egg is fertilized by a sperm that carries a Y chromosome, and it is female if the egg is fertilized by a sperm that carries an X chromosome. The Y chromosome contains a gene, SRY, which will switch on androgen production at a later stage, leading to the development of a male body type. In contrast, the mitochondrial genetic information of the zygote comes entirely from the mother via the ovum. The embryonic period in humans begins at fertilization (penetration

neg: Hyaluronidase of the sperm cell after it has reached the oocyte, by digesting hyaluronan in the corona radiata, thus enabling conception. Gene-targeting studies show that hyaluronidases such as PH20 are not essential for fertilization, although exogenous hyaluronidases can disrupt the cumulus matrix. The majority of mammalian ova are covered in a layer of granulosa cells intertwined in an extracellular matrix that contains a high concentration of hyaluronan. When a capacitated sperm reaches the ovum, it is able to penetrate this layer with the assistance of hyaluronidase enzymes present on the surface of the sperm. Once this occurs, the sperm is capable

neg: Eucestoda a duct system to the oviduct, where, in a modified region, the ovum is enclosed in a shell with yolk cells. After the gonads and their ducts have finished maturing, the female reproductive organs begin to mature. The oviduct develops a vagina and enlarges into the uterus, where fertilization and embryonic development occur. Egg formation is a result of copulation. A proglottid can copulate with itself, with other proglottids in the same worm, or with proglottids in other worms, and hypodermic fertilization sometimes occurs. When a gravid proglottid that is distended with an embryo reaches the end of the strobila,

neg: Blastocyst blastocyst has a diameter of about 0.1–0.2 mm and comprises 200–300 cells following rapid cleavage (cell division). About 1 day after blastocyst formation (5–6 days post-fertilization), which is when the blastocyst usually reaches the uterus, the blastocyst begins to embed into the endometrium of the uterine wall where it will undergo further developmental processes, including gastrulation. Embedding of the blastocyst into the endometrium requires that it hatches from the zona pellucida, which prevents adherence to the oviduct as the pre-embryo makes its way to the uterus. The blastocyst is completely embedded in the endometrium only 11–12 days after fertilization. The

neg: Calcium signaling in cell division of intracellular calcium is activation of the ovum after sperm fertilization. In deuterosome eggs (mammals, fish, amphibians, ascidians, sea urchins, etc.), successful sperm entry leads to a distinct rise in intracellular calcium ions (Ca), with mammals and ascidians displaying a series of intracellular calcium spikes required for completion of meiosis... Unfertilized vertebrate eggs arrest development after meiosis I. This developmental pause is attributed to the vaguely defined cytostatic factor (CSF). Current research suggest “CSF” is actually multiple pathways working together to halt division at metaphase of meiosis II. Upon sperm entry into the egg, Ca is released from intracellular stores,

neg: Oocyte activation there is greater production of reactive oxygen species and therefore greater chance of mutation. Furthermore, sperm are exposed to reactive oxygen species from leukocytes in the epididymis during transit. Additionally, quality control of spermatozoa is much worse than for the ovum, as many sperm are released whereas only one dominant follicle is released per cycle. This competitive selection helps to ensure the most 'fit' ova are selected for fertilisation. Oocyte activation may be artificially facilitated by calcium ionophores, something that is speculated to be useful in case of fertilization failure, such as still occurs in 1–5% of intracytoplasmic sperm injection

neg: Infertility on the cervix, or intrauterine insemination (IUI), in which the doctor or WHNP introduces sperm into the uterus during ovulation, via a catheter. In these methods, fertilization occurs inside the body. If conservative medical treatments fail to achieve a full term pregnancy, the physician or WHNP may suggest the patient undergo in vitro fertilization (IVF). IVF and related techniques (ICSI, ZIFT, GIFT) are called assisted reproductive technology (ART) techniques. ART techniques generally start with stimulating the ovaries to increase egg production. After stimulation, the physician surgically extracts one or more eggs from the ovary, and unites them with sperm in

neg: Pronucleus Pronucleus A pronucleus (plural: pronuclei) is the nucleus of a sperm or an egg cell during the process of fertilization, after the sperm enters the ovum, but before the genetic material of the sperm and egg fuse. Sperm and egg cells are haploid, meaning they carry half the number of chromosomes of somatic cells. The male and female pronuclei don't fuse, although their genetic material does. Instead, their membranes dissolve, leaving no barriers between the male and female chromosomes. Their chromosomes can then combine and become part of a single diploid nucleus in the resulting embryo, containing a full set

neg: Vasectomy to you." The cost of cryo-preservation (sperm banking) may also be substantially less than alternative vaso-vasectomy procedure(s), compared to the costs of in-vitro fertilization which usually run to $15,000. Intracytoplasmic sperm injection: Sperm can be aspirated from the testicles or the epididymis, and while there is not enough for successful artificial insemination, there is enough to fertilize an ovum by ICSI This avoids the problem of antisperm antibodies and may result in a faster pregnancy. IVF (In-vitro fertilization) may be less costly (see aforementioned text) per cycle than reversal in some health-care systems, but a single I.V.F. cycle is often

neg: Somatic cell skin cell. This nucleus contains all of the genetic information needed to produce the organism it was removed from. This nucleus is then injected into an ovum of the same species which has had its own genetic material removed. The ovum now no longer needs to be fertilized, because it contains the correct amount of genetic material (a diploid number of chromosomes). In theory, the ovum can be implanted into the uterus of a same-species animal and allowed to develop. The resulting animal will be a nearly genetically identical clone to the animal from which the nucleus was taken. The

neg: Superfecundation that all five boys shared the same father. In 2016, an IVF-implanted surrogate mother gave birth to two children: one genetically unrelated child from an implanted embryo, and a biological child from her own egg and her husband's sperm. Superfecundation Superfecundation is the fertilization of two or more ova from the same cycle by sperm from separate acts of sexual intercourse, which can lead to twin babies from two separate biological fathers. The term superfecundation is derived from fecund, meaning the ability to produce offspring. Heteropaternal superfecundation refers to the fertilization of two separate ova by two different fathers. Homopaternal

neg: Female reproductive system uterus, Fallopian tubes, and ovaries. The vagina is a fibromuscular (made up of fibrous and muscular tissue) canal leading from the outside of the body to the cervix of the uterus or womb. It is also referred to as the birth canal in the context of pregnancy. The vagina accommodates the male penis during sexual intercourse. Semen containing spermatozoa is ejaculated from the male at orgasm, into the vagina potentially enabling fertilization of the egg cell (ovum) to take place. The cervix is the neck of the uterus, the lower, narrow portion where it joins with the upper part of

neg: Intracytoplasmic sperm injection Intracytoplasmic sperm injection Intracytoplasmic sperm injection (ICSI ) is an in vitro fertilization (IVF) procedure in which a single sperm cell is injected directly into the cytoplasm of an egg. This technique is used in order to prepare the gametes for the obtention of embryos that may be transferred to a maternal uterus. With this method acrosome reaction is skipped. There are several differences within classic IVF and ICSI. However, the steps to be followed before and after insemination are the same. In terms of insemination, ICSI needs one only sperm cell per oocyte, meanwhile IVF needs between 50 and

neg: Beginning of human personhood referred to as fertilization. For fertilization to take place and a baby to begin growing, the sperm cell must come in direct contact with the egg cell." Similarly, a textbook used in Evanston, Illinois stated: "Life begins when a sperm cell and an ovum (egg cell) unite." Catholic philosopher Peter Kreeft goes so far as to say: Well, every biology textbook in the world, before "Roe v. Wade", was not in doubt in answering the question, "When does an individual life of any mammalian species begin?" The answer is, "When the genetic code is complete." When instead of the haploid

neg: Sexual intercourse is likely that the oldest jawed fish on Earth was the first animal to reproduce by copulation. Reproduction among humans usually occurs with penile–vaginal penetration. Male orgasm usually includes ejaculation, a series of muscular contractions that deliver semen containing male gametes known as sperm cells or spermatozoa from the penis into the vagina. The subsequent route of the sperm from the vault of the vagina is through the cervix and into the uterus, and then into the fallopian tubes. Millions of sperm are present in each ejaculation, to increase the chances of one fertilizing an egg or ovum (see sperm

neg: Female reproductive system sperm. During fertilization the egg cell plays a role; it releases certain molecules that are essential to guiding the sperm and allows the surface of the egg to attach to the sperm's surface. The egg can then absorb the sperm and fertilization can then begin. The Fallopian tubes are lined with small hairs (cilia) to help the egg cell travel. The reproductive tract (or genital tract) is the lumen that starts as a single pathway through the vagina, splitting up into two lumens in the uterus, both of which continue through the Fallopian tubes, and ending at the distal ostia

neg: LGBT parenting in Canada near the cervix, a process that can be completed at home; in some cases, sperm is inseminated into the uterus which is a clinical procedure. The use of sperm for insemination is regulated and in some cases a letter of permission from Health Canada prior to use. In vitro fertilization entails fertilizing an egg with sperm outside the body and placing the formed embryo into the uterus of the person who will carry the pregnancy. Here parents or donors may contribute biological tissue, in some cases a surrogate mother may be sought out (see "Surrogacy"). Since 2004, only altruistic surrogacy

neg: Female reproductive system a fetus and gestates until childbirth. If the egg does not embed in the wall of the uterus, a female begins menstruation. The Fallopian tubes are two tubes leading from the ovaries into the uterus. On maturity of an ovum, the follicle and the ovary's wall rupture, allowing the ovum to escape and enter the Fallopian tube. There it travels toward the uterus, pushed along by movements of cilia on the inner lining of the tubes. This trip takes hours or days. If the ovum is fertilized while in the Fallopian tube, then it normally implants in the endometrium when

neg: Torrente (TV series) ask for: a good job, a loving husband and the friendship provided by her best friend, Valeria Velutini. However, she cannot bear children due to a medical problem affecting her uterus. When she discusses the issue with her friend Valeria over Reinaldo's refusal to hire a surrogate, Valeria offers a suggestion: that she become the surrogate, on condition that Reinaldo does not find out about it. Valeria then gets implanted with one of Ana Julia's eggs that has been fertilized by Reinaldo's sperm. However, the situation changes when Ana Julia is involved in a plane crash that leaves here with

neg: Blastocyst use of blastocysts in "in vitro" fertilization (IVF) involves culturing a fertilized egg for five days before implanting it into the uterus. It can be a more viable method of fertility treatment than traditional IVF. The inner cell mass of blastocysts is the source of embryonic stem cells. During human embryogenesis, approximately 5–6 days after fertilization, the cells of the morula begin to undergo cell differentiation, and the morula changes into the blastocyst. In the uterus the zona pellucida surrounding the blastocyst breaks down, allowing it to implant into the uterine wall approximately 6 days after fertilization. Implantation marks the

neg: Uterus transplantation With the availability of in vitro fertilization in 1978, uterine transplantation research was deferred. In Saudi Arabia in 2000, a uterine transplant was performed by Dr. Wafa Fagee, from a 46-year-old hysterectomy patient into a 26-year-old recipient whose own uterus had hemorrhaged after childbirth. The transplanted uterus functioned for 99 days, but ultimately needed to be removed after failure due to blood clotting. Within the medical community there was some debate as to whether or not the transplant could truly be considered to have been successful. Post-operatively, the patient had two spontaneous menstrual cycles, followed by amenorrhoea; exploratory laparotomy confirmed

neg: Reproductive system of gastropods getting modified, the sperm passes into the penis. During mating season, the glandular cells in the penis sheath and prepuce swell to facilitate eversion of the penis. The sperm gets pushed through the penis, where they are introduced into the tail end of its copulatory partner. Within the partner snail, after fertilization from the foreign sperm, the eggs pass into the albumen gland where they are coated in mucus which forms the egg capsule. Eggs are released immediately before oviposition. Unlike in land gastropod species where fertilization occurs in fertilization pockets, fertilization in freshwater species happens at the lower end

neg: Artificial insemination not frozen, and it will not be quarantined. Donor sperm provided in this way may be given directly to the recipient woman or her partner, or it may be transported in specially insulated containers. Some donors have their own freezing apparatus to freeze and store their sperm. Semen used is used either fresh, raw, or frozen. Where donor sperm is supplied by a sperm bank, it will always be quarantined and frozen, and will need to be thawed before use. When an ovum is released, semen is introduced into the woman's vagina, uterus or cervix, depending on the method being

neg: Proembryo Proembryo Proembryo, or pro-embryo, is a botanical term that has been used for centuries, to denote the series of cells that are formed after fertilization within the ovule of a flowering plant, before formation of the embryo. More recently, this same term has been given a more extensive meaning, with reference to a human conceptus not yet implanted into a uterus. This more recent meaning is synonymous with "preembryo" or "pre-embryo", and corresponds to stages with more accepted terms zygote and blastocyst. The word 'preembryo' sometimes is used in ethical contexts to refer a human conceptus at least between fertilization

neg: Theodoxus fluviatilis other opening is for laying eggs. Egg cells originate in the ovary. Egg cells travel through the oviduct to the fertilization chamber, where fertilization occur. Eggs then develop in the glandular uterus. A capsule is formed in the diverticulum next to the uterus. The eggs are then laid. In males, the semen is forming in the testis. The sperm structure of "Theodoxus fluviatilis" was examined by Gustaf Retzius. Then semen travels through the prostate, where it mixes with prostatic fluid. Finally it goes through the vas deferens to the penis. The penis is located on the inner side of the

neg: Germline mutation Germline mutation A germline mutation, or germinal mutation, is any detectable variation within germ cells (cells that, when fully developed, become sperm and ovum). Mutations in these cells are the only mutations that can be passed on to offspring, when either a mutated sperm or oocyte come together to form a zygote. After this fertilization event occurs, germ cells divide rapidly to produce all of the cells in the body, causing this mutation to be present in every somatic and germline cell in the offspring; this is also known as a constitutional mutation. Germline mutation is distinct from somatic mutation.

neg: Human reproduction giving them 23 pairs. After a gestation period, typically for nine months, is followed by childbirth. The fertilization of the ovum may be achieved by artificial insemination methods, which do not involve sexual intercourse. The male reproductive system contains two main divisions: the testes where sperm are produced, and the penis. In humans, both of these organs are outside the abdominal cavity. Having the testes outside the abdomen facilitates temperature regulation of the sperm, which require specific temperatures to survive about 2-3 °C less than the normal body temperature i.e. 37 °C. In particular, the extraperitoneal location of the testes

neg: Embryogenesis Embryogenesis Embryogenesis is the process by which the embryo forms and develops. In mammals, the term refers chiefly to early stages of prenatal development, whereas the terms fetus and fetal development describe later stages. Embryogenesis starts with the fertilization of the egg cell (ovum) by a sperm cell, (spermatozoon). Once fertilized, the ovum is referred to as a zygote, a single diploid cell. The zygote undergoes mitotic divisions with no significant growth (a process known as cleavage) and cellular differentiation, leading to development of a multicellular embryo. Although embryogenesis occurs in both animal and plant development, this article addresses the

neg: Trematoda uterus that opens to the exterior in the genital pore, close to the male opening. In most trematodes, sperm cells travel through the uterus to reach the ootype, where fertilization occurs. The ovary is sometimes also associated with a storage sac for sperm, and a copulatory duct termed "Laurer's canal". Almost all trematodes infect molluscs as the first host in the life cycle, and most have a complex life cycle involving other hosts. Most trematodes are monoecious and alternately reproduce sexually and asexually. The two main exceptions to this are the Aspidogastrea, which have no asexual reproduction, and the schistosomes,

neg: Male Male A male (♂) organism is the physiological sex that produces sperm. Each spermatozoon can fuse with a larger female gamete, or ovum, in the process of fertilization. A male cannot reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and asexually. Most male mammals, including male humans, have a Y chromosome, which codes for the production of larger amounts of testosterone to develop male reproductive organs. Not all species share a common sex-determination system. In most animals, including humans, sex is determined genetically, but in some species it can

neg: Sperm connecting piece contains one typical centriole and one atypical centriole such as the proximal centriole like. The midpiece has a central filamentous core with many mitochondria spiralled around it, used for ATP production for the journey through the female cervix, uterus and uterine tubes. The tail or "flagellum"executes the lashing movements that propel the spermatocyte. During fertilization, the sperm provides three essential parts to the oocyte: (1) a signalling or activating factor, which causes the metabolically dormant oocyte to activate; (2) the haploid paternal genome; (3) the centriole, which is responsible for forming the centrosome and microtubule system. The spermatozoa

neg: Cryptic female choice ovulation as a means of exercising cryptic female choice. By hindering ovulation, a copulatory interaction may be deemed unsuccessful. In rats and golden hamsters, females denied a male's success by failing to prepare their uterus based on male stimulation. After insemination, male sperm are relatively slow and inert in the reproductive tracts or storage areas of the female and are only activated by calcium ionophores in vitro. Thus by releasing or withholding the necessary ions to activate the sperm, females can promote faster motility of sperm towards the egg for fertilization or hinder it by slowing their motility and allowing

neg: Traumatic insemination sperm can migrate through the hemolymph to the female's ovaries, resulting in fertilization. The exact mechanics vary from taxon to taxon. In some orders of insects, the male genitalia (paramere) enters the female's genital tract, and a spine at its tip pierces the wall of the female's bursa copulatrix. In others, the male penetrates the outer body wall. In either case, following penetration, the male ejaculates into the female. The sperm and ejaculatory fluids diffuse through the female's hemolymph. The insemination is successful if the sperm reach the ovaries and fertilize an ovum. Female resistance to traumatic insemination varies from

neg: Reproductive system and deposit sperm. Humans have a high level of sexual differentiation. In addition to differences in nearly every reproductive organ, numerous differences typically occur in secondary sexual characteristics. The male reproductive system is a series of organs located outside of the body and around the pelvic region of a male that contribute towards the reproduction process. The primary direct function of the male reproductive system is to provide the male sperm for fertilization of the ovum. The major reproductive organs of the male can be grouped into three categories. The first category is sperm production and storage. Production takes place

neg: Intracytoplasmic sperm injection twin pregnancies with a second gestational sac with a dead fetus, first trimester screening should be based solely on the maternal age and the nuchal translucency scan as biomarkers are significantly altered in these cases. Intracytoplasmic sperm injection Intracytoplasmic sperm injection (ICSI ) is an in vitro fertilization (IVF) procedure in which a single sperm cell is injected directly into the cytoplasm of an egg. This technique is used in order to prepare the gametes for the obtention of embryos that may be transferred to a maternal uterus. With this method acrosome reaction is skipped. There are several differences within

neg: Intrauterine device and takes a trapezoidal shape within the uterus). They are less effective than copper or hormonal IUDs, with a side effect profile similar to copper IUDs. Their primary mechanism of action is inducing a local foreign body reaction, which makes the uterine environment hostile both to sperm and to implantation of an embryo. They may have higher rates of preventing pregnancy after fertilization, instead of before fertilization, compared to copper or hormonal IUDs. Inert IUDs are not yet approved for use in the United States, UK, or Canada. In China, where IUDs are the most common form of contraception, copper

neg: Zygote haploid cells is called karyogamy. The result of karyogamy is the formation of a diploid cell called zygote or zygospore. This cell may then enter meiosis or mitosis depending on the life cycle of the species. In plants, the zygote may be polyploid if fertilization occurs between meiotically unreduced gametes. In land plants, the zygote is formed within a chamber called the archegonium. In seedless plants, the archegonium is usually flask-shaped, with a long hollow neck through which the sperm cell enters. As the zygote divides and grows, it does so inside the archegonium. In human fertilization, a released ovum

neg: Meiosis some cases all four of the meiotic products form gametes such as sperm, spores, or pollen. In female animals, three of the four meiotic products are typically eliminated by extrusion into polar bodies, and only one cell develops to produce an ovum. Because the number of chromosomes is halved during meiosis, gametes can fuse (i.e. fertilization) to form a diploid zygote that contains two copies of each chromosome, one from each parent. Thus, alternating cycles of meiosis and fertilization enable sexual reproduction, with successive generations maintaining the same number of chromosomes. For example, diploid human cells contain 23 pairs of

neg: Yury Verlinsky A polar body is a cell structure found inside an ovum, which includes the package of chromosomes ejected by the egg before fertilization by sperm. Verlinsky's "insight" was that he could analyze the polar body to look for certain genetic defects in the resulting egg. This approach was useful when both parents were carriers of a genetic defect. He found that by using only eggs with the healthy version of the gene, "the child would be protected even if the father passed on the mutated version," and as a result, his approach produced many healthy pregnancies. He later found that

neg: Sperm donation actual ART method used, the age and medical condition of the female bearing the child, and the quality of the embryos produced by fertilization. Donor sperm is less commonly used for IVF treatments than for artificial insemination. This is because IVF treatments are usually required only when there is a problem with the female conceiving, or where there is a 'male factor problem' involving the female's partner. Donor sperm is also used for IVF in surrogacy arrangements where an embryo may be created in an IVF procedure using donor sperm and this is then implanted in a surrogate. In a

neg: Mitochondrial replacement therapy inserted into a donor oocyte from which the nucleus has already been removed. This egg is fertilized with sperm, and allowed to form a blastocyst, which can then be investigated with preimplantation genetic diagnosis to check for mitochondrial mutations, prior to being implanted in the recipient's uterus. In pronuclear transfer, an oocyte is removed from the recipient, and fertilized with sperm. The donor oocyte is fertilized with sperm from the same person. The male and female pronuclei are removed from each fertilized egg prior to their fusing, and the pronuclei from the recipient's fertilized egg are inserted into the fertilized

neg: Mammalian reproduction of embryogenesis and morphogenesis. When developed enough to survive outside the womb, the cervix dilates and contractions of the uterus propel the fetus through the birth canal, which is the vagina. The ova, which are the female sex cells, are much larger than the sperm and are normally formed within the ovaries of the fetus before its birth. They are mostly fixed in location within the ovary until their transit to the uterus, and contain nutrients for the later zygote and embryo. Over a regular interval, in response to hormonal signals, a process of oogenesis matures one ovum which is

neg: Uterus a double uterus, didelphic uterus, bicornate uterus and others. The reproductive function of the uterus is to accept a fertilized ovum which passes through the utero-tubal junction from the fallopian tube (uterine tube). The fertilized ovum divides to become a blastocyst, which implants into the endometrium, and derives nourishment from blood vessels which develop exclusively for this purpose. The fertilized ovum becomes an embryo, attaches to a wall of the uterus, creates a placenta, and develops into a fetus (gestates) until childbirth. Due to anatomical barriers such as the pelvis, the uterus is pushed partially into the abdomen due to

neg: Ovary Ovary The ovary is an organ found in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilised by a sperm. There is an ovary () found on the left and right sides of the body. The ovaries also secrete hormones that play a role in the menstrual cycle and fertility. The ovary progresses through many stages beginning in the prenatal period through menopause. It is also an endocrine gland because of the various hormones that it secretes. The ovaries are considered the female gonads. Each

neg: Hamster zona-free ovum test hamster test correlates with a lower probability of the man's partner becoming pregnant. Hamster zona-free ovum test The hamster zona-free ovum test (HZFO test), or hamster test is a method for diagnosing male infertility due to the inability of the sperm to penetrate the ova. This test has limited value for most people experiencing infertility. In this test, sperm are incubated with several hamster eggs. After seven to twenty hours, the number of sperm penetrations per egg is measured. The hamster eggs have had the zona pellucida, the outer membrane, removed- hence, "zona-free". Having all eggs penetrated by multiple sperm

neg: Gamete Gamete A gamete (; from Ancient Greek γαμετή "gamete" from gamein "to marry") is a haploid cell that fuses with another haploid cell during fertilization (conception) in organisms that sexually reproduce. In species that produce two morphologically distinct types of gametes, and in which each individual produces only one type, a female is any individual that produces the larger type of gamete—called an ovum (or egg)—and a male produces the smaller tadpole-like type—called a sperm. In short a gamete is an egg (female gamete) or a sperm (male gamete). This is an example of anisogamy or heterogamy, the condition in

neg: Spermicide tubes to the uterus. In fact the deep proper insertion of spermicide should effectively block the cervix so that sperm cannot make it past the cervix, to the uterus, or the fallopian tubes. Scholars K.T. Bartman and et al. study observing the distribution of spermicide containing Nonoxynol-9 in the vaginal tract, showed “After 10 min the gel spread within the vaginal canal providing a contiguous covering of the epithelium of variable thickness.” The sole goal of spermicide is to prevent fertilization. Menfegol is a spermicide manufactured as a foaming tablet. It is available only in Europe. Octoxynol-9 was previously a

neg: Products of conception Products of conception Products of conception, abbreviated POC, is a medical term used for the tissue derived from the union of an egg and a sperm. It encompasses anembryonic gestation (blighted ovum) which does not have a viable embryo. In the context of tissue from a dilation and curettage, the presence of POC essentially excludes an ectopic pregnancy. "Retained products of conception" is where products of conception remain in the uterus after childbirth, medical abortion or spontaneous abortion (colloquially known as miscarriage). Miscarriage with retained products of conception is termed "delayed" when no or very little products of conception have