A prospective controlled study of in-vitro fertilization, gamete intra-fallopian transfer and intrauterine insemination combined with superovulation.

The relative effectiveness of in-vitro fertilization (IVF), gamete intra-Fallopian transfer (GIFT) and intrauterine insemination (IUI) combined with superovulation in the treatment of infertility were compared in 151 couples undergoing a single cycle of treatment. Treatment was selected as appropriate (IVF for tubal disease, GIFT or IUI/superovulation for nontubal infertility) but possible bias due to non-randomization was overcome by all couples having had favourable fertilization in a previous cycle of IVF. Furthermore, in a preliminary study of initial IVF treatment in 265 couples from whom the study patients were drawn, implantation and pregnancy rates in the diagnostic groups were similar. In the definitive study comparing IVF, GIFT and IUI/superovulation, the pregnancy rate observed with GIFT was highest (40%) but this was not significantly higher than with IVF (28%) or IUI/superovulation (20%). However, the implantation rate per egg transferred by GIFT (21%) was significantly higher than the implantation rate per embryo transferred by IVF (11%). Although the pregnancy rates with GIFT were not statistically greater than with IVF, a significant advantage is likely to be observed in larger groups in view of the better implantation rate. The lower pregnancy rates with IUI superovulation are to be expected because of limited ovarian stimulation, they are nevertheless of comparative interest.