Catecholamines in human amniotic fluid

This study was undertaken to determine the amniotic fluid levels of epinephrine (E), norepinephrine (N), and dopamine (D) at different gestational ages in the human. Amniotic fluid obtained from 32 pregnant women undergoing amniocentesis for medical indications was analyzed with a radioenzyme assay for these catecholamines. The gestational ages ranged from 17 to 39 weeks. No patient was in active labor at the time of amniocentesis. The data obtained in this study demonstrated a rise of all three catecholamines at the end of the third trimester: N = 362.7 +/- 61.2 pg/ml (+/- SEM), E = 179.6 +/- 45.4 pg/ml (p < 0.05), and D = 2717.0 +/- 836.6 pg/ml (p < 0.01). The physiologic role for the increasing amounts of catecholamines, especially D, in amniotic fluid is known; however, these amines could be the stimulus for the intrauterine synthesis of prostaglandins as parturition approaches.