Influence of assisted reproductive technology on multiple pregnancy

Abstract

With the recent spread of assisted reproductive technology (ART), about 1% of newborns in Japan are born by ART [1], and the incidence of multiple pregnancy is increasing. Compared with single pregnancy, multiple pregnancy shows a high incidence of maternal complications and premature deliveries and is an important problem in perinatal medicine [2]. Among multiple pregnancies, super twins (triplets or more) and monochorionic multiple pregnancy have particularly high risks. Super twins have been conventionally managed by limiting the number of transferred embryos. After introduction of blastocyst transfer with high selectivity of good embryos, the incidence of monochorionic multiple pregnancy has been increasing. We report the association between ART and multiple pregnancy, especially, the prevention of multiple pregnancy by limiting the number of transferred embryos, the transfer time, and monochorionic multiple pregnancy.