Transplacental passage of insulin in pregnant women with insulin‐dependent diabetes mellitus. Menon R K, Cohen R M, Sperling M A, et al. New England Journal of Medicine, 1990; 323: 309–15

Fifty one babies of insulindependent mothers had cord blood measured for levels of insulin and anti‐insulin antibody. of six mothers who only received human insulin during pregnancy, only human insulin was detected in cord blood, whereas 28 out of 45 of those whose mothers had received animal insulin, up to 27% of total insulin within cord blood proved to be of animal origin. significant correlation between maternal and cord blood levels of both insulin and anti‐insulin antibodies was found. suggesting that considerable amounts of anti‐body bound insulin could bc transferred across the placenta during pregnancy. Furthermore high concentrations of animal insulin in cord blood correlated with both increased birth weight and in particular macrosomia.