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

Objective: To investigate whether endometrial thickness (EMT) is associated with adverse obstetric and neonatal outcomes in fresh in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) cycles.

Design: Retrospective cohort study.

Setting: University-based reproductive medical center.

Patient(s): 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.

Intervention(s): Controlled ovarian hyperstimulation and IVF/ICSI; fresh ET.

Main outcome measure(s): Birth weight, gestational age, small for gestational age (SGA), large for gestational age (LGA), placenta previa, placental abruption, hypertensive disorders, and gestational diabetes mellitus.

Result(s): 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).

Conclusion(s): 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.

Keywords: Birth weight; endometrial thickness; small for gestational age.