Amniotic fluid prolactin levels in rhesus isoimmunized patients.

The concentration of prolactin in the amniotic fluid (AFPRL) was measured in 75 samples obtained in the third trimester of 14 isoimmunized women. There was a uniform decline in prolactin levels with advancing gestation in each pregnancy (r = -0.89 to -0.99). The decline in AFPRL was similar in uncomplicated pregnancies. AFPRL levels were not predictive of umbilical cord hemoglobin or bilirubin levels and amniotic fluid lecithin/sphingomyelin ratio.