Comparison of concurrent pregnancy rates for in-vitro fertilization--embryo transfer, pronuclear stage embryo transfer and gamete intra-fallopian transfer.

Concurrent pregnancy and implantation (sacs/embryos transferred) rates were compared for 84, 77 and 49 cases of in-vitro fertilization-embryo transfer (IVF-ET), pronuclear stage embryo transfer (PROST) and gamete intra-Fallopian transfer (GIFT), respectively. All cases reported occurred during an 18-month interval since the initiation of PROST by our programme. Leuprolide acetate was used with follicle stimulating hormone and human menopausal gonadotrophin for follicular stimulation of all but donor oocyte cases (n = 9). Clinical pregnancy (per transfer) and implantation rates were significantly higher (P less than 0.03) for PROST (52.4%, 20.2%) in comparison with IVF-ET (26.9%, 11.4%). Rates for GIFT (48.9%, 18.4%) were not significantly higher (P = 0.10, 0.14) than for IVF-ET. This was probably due to the lower number of GIFT than PROST procedures performed. The total pregnancy rate for GIFT (biochemical, ectopic and clinical combined) was significantly greater (P less than 0.05) than for IVF-ET. Pregnancy and implantation rates for PROST and GIFT were similar. These results support the use of PROST rather than IVF-ET for all cases in which the woman has one functional Fallopian tube. Furthermore, to maintain equivalent rates of pregnancy with PROST and GIFT, it is suggested that GIFT should not be used for cases of male-factor infertility without first documenting normal rates of in-vitro fertilization with PROST.