RESULTS Normal Pregnancy. Eleven pregnant women were studied at weekly intervals for periods ranging from 24 to 32 weeks. Three hundred and ten estimations were done in this group. An additional 68 assays were made in 40 patients at various stages of pregnancy, a total of 378 estimations being done in 51 patients, 189 in primigravidae and an equal number in multigravidae. Two of the patients in the first group had been attending the sterility clinic before becoming pregnant. None of the patients were suffering from hypertension …