Endometrial thickness is associated with incidence of small-for-gestational-age infants in fresh in vitro fertilization–intracytoplasmic sperm injection and embryo transfer cycles

Abstract

To investigate whether endometrial thickness (EMT) is associated with adverse obstetric and neonatal outcomes in fresh invitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) cycles. Retrospective cohort study. University-based reproductive medical center. Women under the age of 42 years who underwent IVF/ICSI treatment and received fresh ET in our unit from January 2017 to December 2018, resulting in a live singleton birth. Controlled ovarian hyperstimulation and IVF/ICSI; fresh ET. Birth weight, gestational age, small for gestational age (SGA), large for gestational age (LGA), placenta previa, placental abruption, hypertensive disorders, and gestational diabetes mellitus. The risk of being born SGA was statistically significantly increased in the EMT ≤7.5 mm group compared with those from the EMT >12 mm group (adjusted odds ratio [aOR] 2.391; 95% confidence interval [CI], 1.155-4.950). Moreover, maternal body mass index, secondary infertility, preterm delivery, and hypertensive disorders were all independent predictors for SGA. The mean birth weights of singletons in women with EMT ≤7.5 mm were lower than in the groups with EMT >7.5-12 mm and EMT >12 mm (3.25 ± 0.56 kg vs. 3.38 ± 0.51 kg and 3.39 ± 0.53 kg, respectively). After fresh IVF/ICSI-ET, the risk of SGA was increased twofold in women with EMT ≤7.5 mm compared with women with EMT >12 mm. We suggest that women with a thin EMT after obtaining a pregnancy by IVF should receive improved prenatal care to reduce the risk of delivering a SGA infant.