Multiple-gestation pregnancies after assisted reproductive technology treatment: population trends and future directions.

Assisted reproductive technology (ART) treatments, such as in vitro fertilization, have benefited many couples worldwide. However, ART as currently practiced, with the usual transfer of at least two embryos, poses sizable risks for multiple-gestation pregnancy and accompanying serious maternal and child health sequelae. While limiting the number of embryos transferred would appear a straightforward solution, treatments with single-embryo transfer are rare. Likely reasons for this include patient and provider desires to maximize the chance for success in a single treatment given the high cost and lack of insurance coverage, the (sometimes mistaken) belief that transferring more embryos will increase the chance for pregnancy, and the preference for multiple births among some women undergoing ART. Although recent population-based data in the USA and Europe suggest the number of embryos transferred is decreasing, the ART multiple-birth rate remains high. Comprehensive patient-education efforts and continued research on the efficacy of single-embryo transfer are needed.