Correlation between endometrial thickness and perinatal outcome for pregnancies achieved through assisted reproduction technology.

Objective To explore the relationship between endometrial thickness and perinatal outcome in assisted reproductive techniques (ART). Methods A retrospective cohort study was conducted in 1139 infertile women who underwent ART treatment from January 2011 to July 2014. Four groups were divided by endometrial thickness on the human chorionic gonadotropin (HCG) trigger day in fresh embryo transfer cycles or on the progesterone administration day in frozen embryo transfer cycles, as group A (<8 mm), group B (8-10 mm), group C (10-14 mm) and group D (≥14 mm). Two other groups were delineated according to whether uterine lesions were present. The incidence of premature rupture of membranes (PROM), postpartum hemorrhage (PPH) and other common perinatal complications were observed subsequently. Results It was found that the highest incidence of PROM and PPH was in group A (P < 0.05). The incidence of PROM in group B was higher than in groups C and D (P < 0.05). The occurrence of mothers entering the intensive care unit (ICU) was significantly higher in group A than in group B (P < 0.05). However, no significant differences were found in other adverse outcomes. There was no difference in the incidence of adverse perinatal outcome when the endometrial thickness of pre-implantation was not attenuated by uterine lesions. Conclusion The incidence of PROM and PPH increased significantly when the thickness of the endometrium was less than 10 mm before implantation. Correspondingly, the number of mothers treated in the ICU was also higher under these circumstances. To reduce such perinatal placenta-related complications, we should maximize the thickness of the endometrium before transplantation of embryos.