Amniotic fluid cortisol after premature rupture of membranes

Total amniotic fluid cortisol concentration was studied in 12 patients at 24 to 34 weeks of gestation after premature rupture of membranes of one to eight days duration. Rupture of the membranes of less than 24 hours duration was associated with normal amniotic fluid cortisol concentrations. Rupture of membranes for more than 24 hours was associated in 10 of 12 patients with higher than normal amniotic fluid cortisol levels. The rise in amniotic fluid cortisol concentrations following premature rupture of the membranes may reflect increased fetal or maternal cortisol production or both, and could explain enhanced lung maturation in such infants.