This Register reports 18.598 procedures of assisted reproduction performed in 102 centres accredited or affiliated to RED. From the 11 countries that perform these procedures, Brazil contributes with 49.3% of the procedures, followed by Argentine and Mexico with 19.8% and 9.7%, respectively. Each of the other countries contributes with less than 6% of the procedures.

During the year 2001, 13.971 follicular aspirations were performed, which generates 12.777 embryo transfers. From these procedures, 71.5% corresponds to ICSI, with or without Assisted Hatching, 28.1% to IVF and 0.4% to GIFT + others.

Taking IVF and ICSI as a set, the global pregnancy and birth rates by aspiration were 28.0% and 21.8%, respectively. The birth rate by aspiration is the highest got in Latin America.

From the total of the embryo transfers in IVF and ICSI, in 12% 1 embryo was transferred and in 19% 2 embryos. In 28% of the procedures, 3 embryos were transferred and in 41% 4 embryos or more. The media of embryos transfer, as in the year 2000, kept in 3.2 embryos.

The multiple gestation rate was 29.8% (22.1% twins, 7.7% triplets). This percentage is similar to the 30.2% (22.8% twins, 7.4% triplets) reported in the year 2000.

From the IVF and ICSI procedures performed during the year 2001, we got 3615 liveborn babies; 1856 unique (51.3%), 1236 twins (34.2%), 459 triplets (12.7%) and 64 quadruplets (1.8%). Thus, 48.7% of the living newborn child resulted from a multiple gestation.

The premature (= 36 weeks of gestation) and extreme premature (= 31 weeks of gestation) was 15.5% and 2.8%, respectively, for unique births, 55.5% and 9.5% for twins, 89.6% and 20.1% for triplets.

The perinatal mortality was 1.7% for unique births, 7.1% for twins, 9.1% for triplets and 50% for quadruplets or more.

76.8% of the embryos were cryopreserved in 48-72 hours, 18% in pronucleus stage and 5.2% in blastocyst stage. 1657 embryo transfers were performed with a birth rate of 12.9%.

On the other hand, the birth rate by transfer in oocyte donation with fresh embryos was 27.1%, decreasing to 13.2% when the embryos transferred were cryopreserved.

There is no doubt the most severe complication is the multiple gestation and its perinatal result. As the large centers (> 500 cycles) as the small ones (= 100 cycles) transfer an excessive number of embryos. It is urgent to incorporate strategies to facilitate the implementation of programmes with transfer of 01 or maximum 2 embryos in Latin America.