amniotic fluid beta-endorphin ( beta-ep ) and beta-lipotropin ( beta-lph ) were measured by radioimmunoassay after silicic acid extraction and gel chromatographic separation of the two peptides in uncomplicated second-trimester and term pregnancies , in diabetic patients at term , and in pregnancies complicated by rh-isoimmunization , premature labor , and intrauterine growth retardation .
C0032980
second-trimester
C0032961
pregnancies