Effect of single embryo transfer on the risk of preterm birth associated with in vitro fertilization

Purpose To determine whether elective single embryo transfer (eSET) reduces the risk of preterm delivery associated with in vitro fertilization (IVF). Methods This is an observational study of 3125 eSET cycles performed from 2008 to 2009 and reported to the Society for Assisted Reproductive Technology (SART) database. Preterm delivery rates were compared to the overall preterm delivery rate among all patients undergoing IVF over the same time period. Results The 3125 eSET cycles resulted in 1507 live births (live birth rate 48.2 %) Among these deliveries were 27 twins (1.8 %) and one set of triplets (0.07 %). The overall preterm delivery rate (20–37 weeks gestation) following eSET was 17.6 % (269/1527). This is significantly greater than the preterm birth rate for all patients undergoing IVF over the same time period (12 %, P < 0.001). Conclusions Elective single embryo transfer does not reduce the risk of preterm delivery associated with in vitro fertilization (IVF).