A thinner endometrium is associated with lower newborn birth weight during

Area of Science:

• Reproductive Medicine
• Neonatal Health
• In Vitro Fertilization

Background:

• Endometrial thickness (EMT) is a critical factor in successful embryo implantation.
• Optimizing EMT is crucial for improving pregnancy and neonatal outcomes in assisted reproductive technologies.

Purpose of the Study:

• To investigate the association between endometrial thickness (EMT) prior to embryo transfer and newborn birth weight in women undergoing in vitro fertilization-frozen embryo transfer (IVF-FET).

Main Methods:

• Retrospective analysis of singleton live births following IVF-FET between June 2015 and February 2019.
• Collected data on maternal age, neonatal outcomes (birth weight, gestational age, delivery mode, low birth weight percentage, macrosomia incidence), and maternal complications.

Main Results:

• Singleton newborns delivered by patients with EMT > 12 mm had significantly higher birth weights compared to those with thinner endometria.
• Mean birth weight increased with increasing EMT categories (EMT < 8 mm, 8-12 mm, ≥ 12 mm).
• Independent predictors of birth weight included maternal hypertension, premature rupture of membranes, placenta previa, newborn sex, gestational age, delivery mode, number of embryos transferred, and hormone levels.

Conclusions:

• Newborn birth weight is significantly associated with endometrial thickness before embryo transfer in the first FET cycle.
• Lower birth weights are observed in newborns from patients with thinner endometria.
• Enhancing endometrial thickness prior to embryo transfer may be a viable strategy to improve neonatal outcomes in fertility treatments.