ABSTRACT
Multiple pregnancy is the most common treatment-related adverse outcome of assisted reproductive technology (ART) due to the transfer of multiple embryos. Multiple pregnancy is associated with increased fetal/neonatal and maternal risks and a considerable demand on health resources. Preterm birth and fetal growth restriction are common complications in multiple pregnancy and leading causes for perinatal mortality and morbidity. Other important pregnancy complications include pregnancy-induced hypertensive disorders, gestational diabetes, iron deficiency anemia, antenatal and postnatal hemorrhage, and an increased rate of operative deliveries, contributing to increased maternal and perinatal complications. Multiple birth has an impact on parents’ physical and emotional well-being, with an additional strain on the family. Multiple pregnancy is an avoidable risk of ART. The restriction of the number of embryos transferred to the uterus has been gradually implemented over the last three decades. This strategy has resulted in reduction of multiple pregnancy rate, concerning, in particular, triplets and higher-order multiples. The transfer of a single embryo while freezing all other good grade embryos (elective single embryo transfer, eSET) significantly reduces all multiple pregnancies, however without reducing live birth rates. The policy of eSET is now recommended and practiced widely. This policy, in addition to better patient counseling and education can help further reduce the multiple pregnancy rate and risks of pregnancy with ART.
