Impact of a cryopreservation program on the multiple pregnancy rate associated with assisted reproductive technologies

Abstract

To determine the impact of a cryopreservation program on pregnancy rates and multiple-pregnancy rates in ART cycles. Retrospective study. University teaching hospital. Women who underwent stimulation for in vitro fertilization at the Jones Institute for Reproductive Medicine between October 1987 and June 1999. Analysis of pregnancy and multiple-pregnancy rates based on the number of embryos transferred. Implantation; pregnancy and multiple-pregnancy rates. Pregnancy rates per transfer increased from 9% when one embryo was transferred to 20% with two embryos, 35% with three embryos, 40% with four embryos, and 41% with five embryos. The rate of twin pregnancies increased to 21% with two embryos, 23% with three embryos, 21% with four embryos, and 22% with five embryos. The triplet pregnancy rates were 8% with three embryos, 9% with four embryos, and 2% with five embryos. A theoretical model limiting the number of embryos transferred to two with cryopreservation and subsequent transfer yields a cumulative pregnancy rate of 77%, a twin rate of less than 20%, and no triplet or higher-order pregnancies. The use of a cryopreservation program can help maximize pregnancy rates while minimizing multiple-pregnancy rates. Cryopreservation should be considered in all assisted reproductive technology cycles.