Serum cystine aminopeptidase and the normal weight baby in normotensive and hypertensive pregnancy.

The levels of serum cystine aminopeptidase have been studied serially in normotensive and hypertensive mothers who delivered healthy, normal weight-for-dates babies. A normal range, both for enzyme level and maximum and minimum rates of increase of the enzyme during gestation, was established for each group, those of the hypertensive patients exhibiting different characteristics from the curves in normotensive patients. It is suggested that such differences be considered when assessing pregnancies complicated by hypertension.