The results of 12.274 procedures in Assisted Reproduction during 1998, in 84 affiliated centres of the RED were reported. Moreover, a longitudinal analysis of the procedures performed between 1990 and 1998 was included. As in the previous years, Brazil and Argentine have contributed with the majority of the procedures.

From the procedures performed in 1998, 37.3% are related to IVF, 40.3% to ICSI and 19.2% to Assisted Hatching, Soft/Tomi and to a combination of procedures. This way, the techniques in which the micromanipulation of gametes is included, increased from 3.7% of the procedures in 1993 to 59.6% in 1998.

The age of the woman has also experimented some alterations. In 1990, 66.5% of the population aged < 35 and 8.7% = 40. In 1998, 50.4% of the women aged < 35 and 13.9% = 40.

The clinical pregnancy (TEC) and liveborn rates by aspiration were 24.5% and 19.1% for IVF and 26.2% for ICSI, respectively. The 11.074 transferences performed resulted in 3.253 liveborn (1.078 unique, 1.065 twins, 396 triplets and 84 quadruplets or more).

As in global terms as to the interior to each diagnosis category, the TEC by aspiration decreases with the age of the woman. The effect of the age equally affects the implantation rate, which decreases from 13.7% in women aged 35 to 6.5% to women aged =40.

In a longitudinal comparison of the pregnancy rate by transference in IVF, we can observe that since 1995 there was a significant increase that happens each year. In the same way, in 1998 the implantation rate in IVF was significantly higher than in 1995, what suggests an improvement in the manipulation of the Assisted Reproduction techniques.

In global terms, the TEC increases as the number of embryos transferred, as in IVF as in ICSI. The transference of more embryos dos not represent an increase in the gestation rates, it only increases the multiple gestation rates.

The global rate of multiple gestation in the last years has kept around 30%. In a way, it is consequence of the number of embryos transferred, which has maintained in about 3.3. The global rate of multiple gestation when transferred two, three or four embryos increases from 15.3% to 27.7% and to 33.4% respectively. The additional problem is that the extreme multiple gestation hasn’t appeared in triplets or more yet; to transfer two, three embryos, the extreme multiple gestation increases to 4.1% and 11.8% to transfer four embryos. Women aged = 40 do no present triplets when transferred three, four or five embryos; however, the twin rate reaches 40% when four embryos are transferred. Considering the multiple gestation is a sign of reproductive evidence, the concept to transfer more embryos to the older woman isn’t necessarily an expression of good medical practice. The RED will make all educational effort to prepare the centres in the transference of a lower number of embryos and, so, to avoid the afflict the extreme multiple gestation is.