Ectopic Pregnancy Risk with Assisted Reproductive Technology

Abstract

To investigate the optimal methods for the reduction of ectopic pregnancy incidence due to assisted reproductive technology (ART). Day five or six blastocyst transfer may decrease ectopic pregnancy rates when compared with day three transfer, similarly, frozen-thawed embryo transfer may lessen the risk of ectopic pregnancy relative to fresh embryo transfer. Single embryo transfers decrease ectopic pregnancy risk and have similar clinical pregnancy outcomes as double embryo transfers. Ectopic pregnancy remains a major cause of maternal morbidity and mortality in the first trimester of pregnancy. Compared with spontaneously conceived pregnancies, pregnancies resulting from in vitro fertilization (IVF) treatments are initially associated with an increased risk of an ectopic implantation. Many risk factors related to ART have been linked to increased ectopic pregnancy risk, though the exact mechanism underlying the link between ectopic pregnancy and ART remains unclear. Tubal factor infertility is the major risk factor for ectopic pregnancy following IVF. Day of transfer, fresh or frozen-thawed cycle single or double transfer are the main controversial factors regarding ectopic pregnancy risk. According to recent data, day 5 blastocyst transfer has decreased ectopic pregnancy risk than day 3, also frozen-thawed cycle has lower risk of ectopic implantation than fresh cycles. Single frozen-thawed blastocyst transfer may thus be the best choice for reducing ectopic pregnancy incidence among IVF patients. Further studies should be done to compare the ectopic pregnancy rates between the single frozen-thawed blastocyst transfer and spontaneous pregnancies.