Placental lactogen levels as guide to outcome of threatened abortion.

The clinical value has been assessed of circulating placental lactogen levels as a pointer to the outcome in a patient with vaginal bleeding in early pregnancy. By using a semiautomated radioimmunoassay the normal range of values for the first and second trimesters has been established. In patients admitted with vaginal bleeding after the eighth week of gestation estimation of plasma human placental lactogen showed that patients with low levels were those in whom the abortion was completed during the first admission. Women whose pregnancies continued normally or who aborted after their first discharge from hospital had normal levels. In a small group sampled before the onset of bleeding but who later aborted the mean levels were lower than normal. This simple and inexpensive test can indicate those women in whom abortion is inevitable and could be used to reduce substantially the length of hospital stay in this common complication of early pregnancy.