THE VARIABILITY OF PLASMA OESTRADIOL CONCENTRATION IN LATE PREGNANCY

Abstract
Summary: Plasma oestradiol concentration was measured daily in five normal subjects for five consecutive days during the third trimester of pregnancy. The overall co‐efficient of variation was 7.9 per cent for conjugated oestradiol, 7.2 per cent for the unconjugated steroid and 7.4 per cent for the total oestradiol. Single measurements were made in a further 30 women. Generally the conjugated and unconjugated steroid were present in equal amounts.