Ovulation-induced frozen embryo transfer regimens in women with polycystic ovary syndrome: a systematic review and meta-analysis

To evaluate whether the type of frozen embryo transfer (FET) regimen — ovulation-induced regimens vs. hormone replacement therapy regimens (HRT) — is associated with live birth rates and the risk of hypertensive diseases of pregnancy (HDP) in women with polycystic ovary syndrome (PCOS).

All studies in PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were searched using a combination of MeSH terms and keywords. Inclusion criteria included studies on women with a diagnosis of PCOS, utilization of FET, and reporting of pregnancy and/or obstetric outcomes. Studies were excluded if they were case series or conference abstracts or used other FET regimens. A random effects meta-analysis was performed. Primary outcomes include relative risk (RR) of live birth and HDP.

Eleven studies were included in the meta-analysis for the final review. Ovulation-induced regimens were associated with a higher live birth rate (8 studies, RR 1.14 [95% CI 1.08, 1.21]) compared to HRT regimens. The risk of HDP (3 studies RR 0.78 [95% CI 0.53, 1.15]) was not significantly different. Ovulation-induced regimens were associated with a lower miscarriage rate (9 studies, RR 0.67 [95% CI 0.59–0.76]). Rates of clinical pregnancy (10 studies, RR 1.05 [95% CI 0.99, 1.11]) and ectopic pregnancy (7 studies, RR 1.40 [95% CI 0.84, 2.33]), were not significantly different.

This SR/MA demonstrates that for women with PCOS, ovulation-induced FET regimens are associated with higher rates of live birth and lower rates of miscarriage compared to HRT regimens.