[1997 FIVNAT general balance].

In 1997, the French National Register on in vitro fertilization, FIVNAT, has collected information on 3,854 initiated cycles and 36,583 oocyte recoveries, from which 61.2% were conventional IVF cycles and 38.6% were ICSI. For conventional IVF, the percentage of infertilities of tubal origin was 49.7%, whereas 45% of the recoveries involved a male factor. The stimulation regimen involved a GnRH in 95% of the cases mostly with a long blockage period (82.6%) which was associated to the highest pregnancy rate. The mean number of transferred embryos significantly decreased to 2.50 +/- 0.95 per transfer. Only 9.2% of the transfers involved more than 3 embryos, and were associated to a relatively poor pregnancy rate, confirming that they were preferently realised in couples with poor chances of pregnancy. Finally, the pregnancy rate per recovery (20.5%) and per transfer (26.0%) remained at the same level as in 1996.