Maternal Folate and Vitamin B 12 Concentrations During Pregnancy Influence Neonatal Nutritional Status and Adiposity: Results from the OBESO Cohort.

BACKGROUND/

OBJECTIVES

Folate and B12, among other B vitamins, are methyl donors and contribute to multiple DNA methylation processes. Maternal deficiency of these nutrients may be associated with impaired fetal growth, affecting the nutritional status and adiposity of the newborn. This study aimed to describe maternal folate and B12 status throughout pregnancy and evaluate its association with neonatal nutritional status.

METHODS

We studied 90 healthy pregnant women and their babies from the prospective OBESO cohort (Mexico City). Serum folate and B12 concentrations were measured (ELISA) in the first and third trimesters of pregnancy. Deficiency was considered if serum folate was <4 ng/mL, red blood cell folate (RBC) < 151 ng/mL, active B12 < 40 pmol/L, and total B12 < 203 pg/mL). Maternal supplementation of these nutrients was recorded. Newborn assessment (24-72 h) included weight (BW), length (L), waist circumference (WC), and fat mass percentage (%FM; air-displacement plethysmography). Newborn nutritional status indexes were computed and interpreted (BMI/age and length/age) (term-WHO, preterm-Intergrowth). Mean differences, correlations, and multiple linear and logistic regressions were performed (SPSS v. 29).

RESULTS

One-third of women had total vitamin B12 deficiency at the end of pregnancy; no folate deficiency was observed. High doses for both folic acid and B12 supplementation were identified in the third trimester (2057.04 ± 2100.74 μg/d and 7.35 ± 4.56 μg/d). Higher first- and third-trimester maternal active B12 concentrations predicted higher WC and reduced the risk of LBW. Higher first-trimester Thcy levels increased the risk of stunting. Higher third-trimester total B12 and folate concentrations predicted higher WC; the latter was associated with higher FM% at birth.

CONCLUSIONS

Maternal folate, B12, and Thcy levels influence newborn nutritional status alterations, including adiposity markers. It is vital to guarantee an optimal and balanced maternal B-complex status throughout pregnancy.