First Trimester Mean Glucose Level on Continuous Glucose Monitoring Is Associated with Infant Birth Weight

Area of Science:

• Maternal-Fetal Medicine
• Endocrinology
• Metabolic Health

Background:

• Predicting infant birth weight is crucial for maternal and neonatal health.
• Limited data exists comparing continuous glucose monitoring (CGM) metrics with oral glucose tolerance test (OGTT) values for birth weight prediction in non-diabetic pregnancies.

Purpose of the Study:

• To evaluate the association between CGM metrics and OGTT values in early and mid-pregnancy with infant birth weight tertiles.
• To compare the predictive performance of CGM versus OGTT for identifying infants in the highest birth weight tertile.

Main Methods:

• A longitudinal observational study included 113 pregnant women without pre-existing diabetes.
• CGM data was collected in the first and second trimesters; OGTT was performed at mid-pregnancy.
• Multinomial logistic regression analyzed the relationship between glucose metrics and birth weight tertiles, adjusting for confounders.

Main Results:

• Higher first-trimester mean glucose and second-trimester time above range (CGM) were linked to higher birth weight tertiles.
• First-trimester mean glucose (CGM) significantly predicted the highest birth weight tertile (aOR 3.11, P=0.022).
• No significant association was found between OGTT glucose values and infant birth weight outcomes.

Conclusions:

• CGM-derived mean glucose levels in early pregnancy show potential as a superior predictor of high infant birth weight compared to mid-pregnancy OGTT.
• These findings suggest CGM may offer earlier insights into fetal growth related to maternal glucose metabolism.