Taking folate in pregnancy and risk of maternal breast cancer

Abstract

From June 1966 to June 1967, 3187 women were identified as potentially eligible for a trial of folate supplementation.3 4 At her booking visit, the mother's age, gestation, parity, weight, and blood pressure were recorded, and blood was taken to measure serum folate concentrations. Tablets were supplied in six colours, two of which contained folate in 0.2 mg and 5 mg daily doses. The tablets were kept in numbered drawers and distributed in sequence. The trial was double blind. The husband or partner's occupation at the time of delivery was used to determine social class. Linking the trial data to the Aberdeen maternity and neonatal databank added information on maternal smoking and maternal height. No women withdrew from the trial. Compliance was assessed by self report and by measurement of folate status.