The process by which male and female gametes (spermatozoa and oöcytes respectively) fuse to form a zygote which develops, by a complex process of cell division and di?erentiation, into a new individual of the species. In humans, fertilisation occurs in the FALLOPIAN TUBES. Sperm deposited in the upper vagina traverse the cervix and uterus to enter the Fallopian tube. Many sperm attempt to penetrate the zona pellucida surrounding the oöcyte, but only one is able to penetrate the oöcyte proper and this prevents any other sperm from entering. Once the sperm has entered the oöcyte, the two nuclei fuse before the zygote begins to divide.
Fertilisation of the egg (ovum) outside the body. The fertilised ovum is then incubated until the blastocyst stage develops, when it is implanted into the UTERUS. The procedure was developed in Britain and the ?rst successful in vitro baby, a girl, was born in 1978. IVF is used when a woman has blocked FALLOPIAN TUBES or when the sperm and ovum are unable to fuse in the reproductive tract. Hormone treatment results in the potential mother’s producing several mature ova, some of which are removed from the ovary using a LAPAROSCOPE and fertilised with her partner’s semen. (See ASSISTED CONCEPTION.)... in vitro fertilisation (ivf)
Acts of the UK parliament in 1990 and 2008, establishing and amending principles for the legal supervision, by the Human Fertilisation and Embryology Authority, of the creation, use, and storage of human embryos outside the body and of their use in treatment and research. The 2008 amendments included a ban on sex selection for social reasons, recognition of same-sex couples as potential legal parents, and regulations related to developing areas of research using embryos. The 1990 Act had also reduced the legal time limit for most abortions from 28 weeks gestation (as in the 1967 Abortion Act) to 24 weeks. Interpretation and regulation of principles and practice in this rapidly developing area of research and practice continue and are often controversial.... human fertilisation and embryology acts
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