FETAL LUNG MATURATION .3. AMNIOTIC-FLUID CORTISOL-CORTISONE RATIO IN PRETERM HUMAN DELIVERY AND RISK OF RESPIRATORY-DISTRESS SYNDROME

Abstract

Cortisol and cortisone were measured in amniotic fluid samples obtained within 24 h of delivery of 50 premature infants. When expressed as cortisol/cortisone ratios, the ratio tends to rise with advancing gestational age, although statistical significance is not attained. Both cortisol concentration and the cortisol/cortisone ratio are significantly lower in the amniotic fluid of infants who develop respiratory distress syndrome than in those with mature lung function (cortisol: 19.2 .+-. 10.3 ng/ml vs. 26.1 .+-. 9.4, P < .02; cortisol/cortisone ratio: 1.2 .+-. 0.6 vs. 2.0 .+-. 0.8, P. < .001). These findings also hold in the subgroup of infants < 32 wk gestation but not in those infants at or beyond the 32nd wk. The amniotic fluid cortisone concentration is significantly lower in infants born after spontaneous labor beginning with rupture of the membranes as opposed to after contractions or bleeding (13.2 .+-. 3.6 ng/ml vs. 16.3 .+-. 6.1, P < .05), although the cortisol concentrations and the cortisol/cortisone ratios are not significantly different.