The Association of Maternal Folate and Vitamin B12 Concentrations During Pregnancy with Neonate Birth Weight in South Asians and White Europeans Living in Canada: START, FAMILY and CHILD Birth Cohorts

Abstract

Background: Folate and vitamin B12 have interdependent metabolic functions that are essential for neonate growth outcomes (i.e. birth weight) based on studies from India. The objective of this research was to evaluate the association of maternal folate and vitamin B12 concentrations with neonate birth weight in South Asian (SA) and white European (WE) populations. Methods: In this cross-sectional analysis of prospective cohort studies, maternal and neonatal data were collected during the second trimester from 3758 mother-child dyads living in Canada. Maternal diet and supplement use were assessed using a validated food frequency questionnaire. Biochemical indicators were analyzed in a subset of SA mothers. Birth weight was measured within 72 hours of delivery. All regression analyses were performed unadjusted and with adjustment for identified covariates. Results: Maternal folate and vitamin B12 (dietary, supplemental and total) were not associated with neonate birth weight in SA and WE pregnant women. Higher consumption of milk products by SA women was associated with higher birth weight (β=0.06; p=0.01), whereas higher consumption of egg by WE women was associated with lower birth weight (β=-0.19; p<0.01). Folate and vitamin B12 deficiency in the SA subgroup was 13.7% and 17.8%, respectively. Maternal serum vitamin B12 status was inversely associated with birth weight (β=-0.16; p=0.03). Conclusions: Folate and vitamin B12 may be proxies for poor nutritional status. Therefore, folate and vitamin B12 may have an association with neonate birth weight in a less developed area (i.e. India) rather than in a highly developed area (i.e. Canada). Highly developed countries have an adequate intake of folate and vitamin B12 and thus a higher nutritional baseline status. These findings complement current research on folate and vitamin B12 concentrations with birth weight in well-nourished populations.