The thicker the endometrium, the better the neonatal outcomes?

Area of Science:

• Reproductive Medicine
• Neonatal Outcomes
• In Vitro Fertilization (IVF)

Background:

• Live birth rates may correlate with endometrial thickness (EMT) after fresh embryo transfer (ET).
• The association between EMT and neonatal outcomes in fresh IVF cycles remains unclear.

Purpose of the Study:

• To investigate the relationship between endometrial thickness (EMT) on the hCG trigger day and neonatal outcomes for singletons born after fresh embryo transfer (ET).

Main Methods:

• Retrospective study of 2010 women undergoing autologous IVF cycles.
• Multivariable regression analysis and smooth curve fitting to assess EMT's impact on neonatal outcomes.
• Threshold effect analysis to determine the accurate cutoff value of EMT.

Main Results:

• Reduced odds of preterm delivery (PTD) observed with increasing EMT (e.g., 9.00-9.90 mm: 45% reduction; >11 mm: 75% reduction).
• Increasing EMT correlated with decreased PTD and increased gestational age (GA).
• An EMT ≤7.8 mm was identified as a predictor for increased PTD odds and reduced GA.

Conclusions:

• A thin endometrium (≤7.8 mm) on hCG trigger day is associated with increased odds of preterm delivery in singletons following fresh ET.
• While increased EMT shows a trend towards better outcomes, the clinical relevance of modest GA differences requires further investigation.
• The study's retrospective design is a limitation; further prospective research is warranted.