Eggs are obtained and mixed with the partner’s semen, then introduced into the woman’s Fallopian tubes for fertilisation to take place. The fertilised egg travels to the uterus where IMPLANTATION occurs and pregnancy proceeds. A variation of GIFT is zygote intrafallopian transfer (ZIFT) in which early development of the fertilised eggs happens in the laboratory before the young embryo is transferred to the Fallopian tubes. GIFT is best used in couples with unexplained infertility or with minor degrees of male or female cervical factor infertility. The success rate is about 17 per cent. (See also ARTIFICIAL INSEMINATION.)