The incidence of multiple pregnancy after in vitro fertilization and embryo transfer, gamete, or zygote intrafallopian transfer.

This retrospective study concerns the incidence of multiple pregnancy after the replacement of three conceptus using different techniques of assisted reproduction. During a 2-year period, 713 in vitro fertilization-embryo transfers (IVF-ETs) with three embryos, 190 gamete intrafallopian transfers (GIFT) with three oocytes, and 161 zygote intrafallopian transfers (ZIFT) with three zygotes were performed. Although we observed significant differences in implantation and pregnancy rates (PRs), the three techniques resulted in high multiple PR. At 20 weeks, 16% of GIFT pregnancies, 27% of ZIFT pregnancies, and 32% of IVF-ET pregnancies were multiple. Therefore we recommend to limit the number of conceptus transferred to a maximum of three in all cases.