An evaluation of human placental lactogen levels in hypertension of pregnancy.

Maternal plasma levels of human placental lactogen (HPL) are decreased in hypertensive pregnancies and the concentration is related to the severity of the condition. Of infants who had HPL concentrations in the fetal danger zone (more than 2 SD's below normal mean) 75 per cent developed fetal distress, neonatal asphyxia or were light for dates. Patients who are identified in this way have lighter infants and placentae than their unidentified counterparts with normal HPL levels.