in vitro fertilization

Allowing eggs and sperm to unite in a laboratory to form embryos. The embryos (properly called pre-embryos in their two- to eight-celled state) are stored by cooling to the temperature of liquid air (cryopreservation) until they are implanted into the womb of the otherwise infertile mother (an extension of artificial insemination). The first baby to be produced by this method was Louise Joy Brown, born in 1978 at Oldham General Hospital, Lancashire, UK. In cases where the Fallopian tubes are blocked, fertilization may be carried out by intra-vaginal culture, in which egg and sperm are incubated (in a plastic tube) in the mother's vagina, then transferred surgically into the uterus.

Recent extensions of the in vitro technique have included the birth of a baby from a frozen embryo (Australia 1984) and from a frozen egg (Australia 1986). British doctors were pioneers in the field. The technique is now common in the USA. As yet the success rate is relatively low; only 15%–20% of in vitro fertilizations result in live births.