Folate Nutrition Status in Mothers of the Boston Birth Cohort, Sample of a US Urban Low-Income Population.

OBJECTIVES: To examine maternal folic acid supplementation and plasma folate concentrations in the Boston Birth Cohort, a predominantly urban, low-income, minority population in Boston, Massachusetts.

METHODS: This report includes 7612 mothers with singleton live births (3829 Black, 2023 Hispanic, 865 White, and 895 others) enrolled in the Boston Birth Cohort at the Boston Medical Center, during 1999 to 2014. Folic acid supplementation during preconception and each trimester was obtained via interview questionnaire. In a subset (n = 2598), maternal plasma folate concentrations were measured in blood samples drawn within a few days of delivery.

RESULTS: The percentage of mothers taking folic acid supplementation almost daily during preconception and the first, second, and third trimesters were 4.3%, 55.9%, 59.4%, and 58.0%, respectively. Most striking, we observed a wide range of maternal plasma folate concentrations, with approximately 11% insufficient (< 13.4 nmol/L) and 23% elevated (> 45.3 nmol/L).

CONCLUSIONS: Findings indicate that fewer than 5% of mothers in the Boston Birth Cohort started folic acid supplements before pregnancy, and approximately one third of mothers had either too low or too high plasma folate levels, which may have important health consequences on both the mother and the child.