Hormone Levels in Threatened Abortion

Summary Fifty‐five patients admitted to hospital with the diagnosis of threatened abortion were assessed by means of urinary oestrogen, pregnanediol and chorionic gonadotrophin assays and by vaginal cytology. Oestrogen excretion was abnormally low (below the first percentile for the period of gestation) in 22 patients all of whom aborted, usually within a week of the measurement. Twenty‐two of the 33 patients with oestrogen values in the normal pregnancy range had pregnancies which continued and resulted in surviving infants. Eleven patients with normal oestrogen values subsequently aborted. These abortions occurred more than one week after the original assessment and usually in the second trimester. Pregnanediol measure ments provided comparable information. In patients who aborted, vaginal cytology and initial chorionic gonadotrophin levels were less useful investigations.