To assess whether maternal plasma folate and vitamin B12 in the first trimester of pregnancy are associated with child neurodevelopment during the first 30 months of life, and whether those associations are modified by maternal methylenetetrahydrofolate reductase677C>T (MTHFR677C>T) polymorphism.
We conducted a longitudinal study of 181 pairs (mother-child) who participated in a prospective perinatal cohort in the State of Morelos, Mexico. We determined maternal plasma concentrations of folate and vitamin B12 in the first trimester of pregnancy by radioimmunoassay. MTHFR677C>T genotypes were determined by PCR. We used the Bayley Scale of Infant Development II to evaluate child neurodevelopment at ages 1, 3, 6, 12, 24 and 30 months
About 6% of the women had low folate concentrations (<4 ng/ml) and 15% had an excess of folate (> 13.4 ng/ml), while 42% had low concentrations of vitamin B12 (<203pg/ml); among them, 32% were carriers of the MTHFR 677TT genotype. We observed a reduction pattern between folate and mental development among the offspring of MTHFR 677CC carriers. When plasma vitamin B12 was low, there was an increasing pattern of psychomotor development among offspring of MTHFR 677TT carriers.
Our results show that not only folate and vitamin B12 intake but also maternal genetic traits are cofactors of infant neurodevelopment.