Received November 10, 2012
Accepted December 17, 2012

Background: Reducing the rate in IVF of multiple births and associated perinatal complications has become the major challenge in Latin America, due to is association with a significant increase in the prematurity, and perinatal mortality. Methods: We selected all procedures involving the transfer of IVF embryos, reported to the Latin America Registry of ART, initiated between January 1998 and December 2008. A Poisson regression analysis was performed, stratified by woman´s age to analyse the trend in the transfer of 2, 3 and ≥4-embryos and ≥triple-pregnancy rate. Results: A total of 164,874 IVF/ICSI transfers were considered. Overall, there was a decline in the proportion of procedures performed in women aged ≤34 years old from 51% to 43%; and an increase of ICSI procedures from 61% to 86%. All age groups experienced a reduction in the proportion of ≥4-embryos transfers and an increase in that of 2-embryo transfers. Overall, the clinical pregnancy rate improved from 29% to 35% (p=0.01); and the incidence of ≥triple-pregnancy decreased from 8% to 3% in 2008 (p<0.001), while twin pregnancy remained stable (~20%) Conclusions: Our data support the policy of transferring less embryos. It shows a decline in the mean number of embryos transferred and proportion ≥4-embryos transfers. Moreover, it reports a clinical pregnancy rate which instead of being reduced, has shown an increase over the 10-year period.