Introduction: Deviations from normal fetal growth are associated with abnormal neonatal fat distribution and predispose to lifetime obesity. Factors affecting fetal growth include maternal obesity. Recent evidence suggests that maternal visceral obesity negatively affects fetal fat composition and fetal obstetric outcomes. However, there is a dearth of research investigating the relationship between maternal visceral adiposity and fetal fat composition throughout pregnancy.
Methods: This is a retrospective analysis of 1363 women at a tertiary perinatal ultrasound centre from 2012-2014. Maternal subcutaneous fat thickness and body mass index were used to correlate with fetal fat measures in the second and third trimester. The maternal abdominal SFT measurement has been used as a surrogate for central obesity. Neonates were divided into BW quartiles for statistical analysis. Fetal fat thickness was measured by the first author blinded against clinical data.
Results: Outcome data were available for 845 and 674 women in the second and third trimesters respectively. Maternal SFT was positively correlated with fetal abdominal subcutaneous fat in Q2 babies (p=0.01) and with negative correlation with fetal peripheral fat on the lowest BW quartile babies Q1 (p=0.04). Multivariate analysis showed that maternal SFT is a positive predictor of fetal abdominal subcutaneous fat for Q4 babies in the second trimester (p=0.04).
Conclusion: Maternal adiposity can predict fetal fat distribution in the second trimester of pregnancy. The observed trend in the correlation of fetal fat distribution with maternal measures of adiposity was weak. Further prospective research may determine whether these correlations are reproducible and stronger.