Researchers from various departments and institutions in China recently collaborated on a study published in the American Journal of Obstetrics and Gynecology. According to the study, women with polycystic ovarian syndrome (PCOS) are at increased risk of ectopic pregnancy after fresh ET (embryo transfer) cycles, but not after frozen ET cycles.

The study was completed as a retrospective cohort. Medical records were pulled for 5,339 women who experienced clinical pregnancy with the aid of in-vitro fertilization (IVF). About 200 of the women were diagnosed with PCOS prior to IVF. The remaining women were used as the control group.

Fresh ET cycles posed a three times greater risk of ectopic pregnancy in women with PCOS, but the same increased risk was not found in frozen ET cycles. Frozen cycles resulted in comparable ectopic pregnancy rates across PCOS and non-PCOS participants when controlled ovarian hyperstimulation was not used.

Women with PCOS may be best treated with cryo-thawed ET without controlled ovarian hyperstimulation.

Source: Wang J, Wei Y, Diao F, Cui Y, Mao Y, Wang W, Liu J. The association between polycystic ovary syndrome and ectopic pregnancy after in vitro fertilization and embryo transfer. Am J Obstet Gynecol. 2013 May 6. pii: S0002-9378(13)00479-1. doi: 10.1016/j.ajog.2013.05.007.