Maternal serum folate status during early pregnancy: Sex-specific association with neonatal adiposity

Background & aims: Early pregnancy folate has been associated with GDM and possible adiposity in the newborn. The present study examined associations between maternal early pregnancy folate levels and sex-specific neonatal anthropometry. We further explored possible mediation by maternal glycemia on the association between folate and neonatal adiposity.

Methods: Sub-group data (n = 511) from a UK multi-ethnic early pregnancy longitudinal study (micronutrients in Pregnancy as a Risk factor for gestational Diabetes and Effects on mother and baby; PRiDE) was used. Maternal serum folate was assessed during early pregnancy (Mean ± SD = 12.5 ± 1.6 gestational weeks) and infant anthropometry including skinfold thickness (SFT) and mid-upper arm circumference (MUAC) at birth. Multiple linear regression was performed to analyse the relationship between maternal folate and infant adiposity indices. Interaction analysis was used to identify maternal glucose mediation of this relationship.

Results: Excess folate levels (≥45 nmol/l) were found in 40.3 % pregnant women (n = 206). Early pregnancy folate (1 SD unit) was positively associated with male newborn triceps SFT (std β = 0.17 (95 % CI: 0.06, 0.29; p < 0.05)) after adjusting for key maternal and infant confounders in multiple comparisons using Benjamini-Hochberg procedure. However, no associations were seen in female newborns. No influence of maternal fasting (FPG) and 2-h plasma glucose (2 h-PG) were detected on the association between folate and newborn anthropometry.

Conclusion: Our findings suggest a potential sex-specific influence of maternal folate on infant anthropometric indices. The association between early pregnancy folate on newborn adiposity was not mediated by maternal FPG and/or 2 h-PG at 24–28 weeks.