NUTRITION IN PREGNANCY AND THE CONCENTRATIONS OF PROINSULIN, 32-33 SPLIT PROINSULIN, INSULIN, AND C-PEPTIDE IN CORD PLASMA

As insulin is a major fetal growth hormone, we have related the mother 's nutrient intakes (assessed by a food frequency questionnaire) and o ther influences associated with fetal growth to the baby's concentrati ons of insulin and its propeptides in umbilical cord plasma. Among 391 term babies studied, those whose mothers had high energy intakes in e arly pregnancy and low protein intakes in late pregnancy had lower cor d plasma concentrations of 32-33 split proinsulin, insulin, and C-pept ide. Concentrations of split proinsulin fell by 0.66 (95 % CI 0.29 to 1.03, p = 0.0006) log pmol l(-1) for each log kcal increase in the mot her's energy intake in early pregnancy and by 0.005 (95% CI 0.000 to 0 .010, p = 0.04) log pmol l(-1) for each g decrease in protein intake i n late pregnancy. Insulin and propeptide concentrations were however u nrelated to the mother's height and body mass index, and to smoking du ring pregnancy. These observations parallel recent studies relating th e same pattern of dietary intakes to impaired fetal and placental grow th. Although dietary intakes assessed by food frequency questionnaires allow only cautious conclusions, our findings could have implications for the offspring's risk of Type 2 diabetes mellitus in adult life.