Author:
Jwa Seung Chik,Takamura Masashi,Kuwahara Akira,Kajihara Takeshi,Ishihara Osamu
Abstract
AbstractStudies have consistently reported a significantly reduced incidence of ectopic pregnancy (EP) for frozen-thawed embryo transfer (ET) cycles compared with fresh cycles. However, only a few studies reported an association between endometrial preparation protocols on EP and results were conflicting. A registry-based retrospective cohort study of 153,354 clinical pregnancies following frozen single ETs between 2014 and 2017 were conducted, of which 792 cases of EP (0.52%) were reported. Blastocyst embryo transfers accounted for 87% of the total sample and were significantly associated with a decreased risk for EP compared with early cleavage ET (0.90% vs. 0.46%, adjusted OR = 0.50, 95% CI, 0.41 to 0.60). Compared with natural cycles, hormone replacement cycles (HRC) demonstrated a similar risk for EP (0.53% vs. 0.47%, adjusted OR = 1.12, 95% CI, 0.89 to 1.42). Subgroup analysis with or without tubal factor infertility and early cleavage/blastocyst ETs demonstrated similar non-significant associations. Endometrial preparation protocols using clomiphene (CC) were associated with a significantly increased risk for EP (1.12%, adjusted OR = 2.34; 95% CI, 1.38 to 3.98). These findings suggest that HRC and natural cycles had a similar risk for EP. Endometrial preparation using CC was associated with an increased risk of EP in frozen embryo transfer cycles.
Funder
Health and Labour Sciences Research Grants
Publisher
Springer Science and Business Media LLC