Comparison of Glucocorticoid Conjugates with Other Indexes of Fetal Maturation

Abstract

Controversy exists as to whether cortisol acts physiologically to accelerate human fetal lung maturation. Recent data show that cortisol and corticosterone conjugates (GCS) rise 5-fold in amniotic fluid late in pregnancy and correlate well with the palmitic/steric (P/S) ratio (r = 0.79). GCS was compared with various tests of fetal maturation. Cases (38) compared with the lecithin/sphingomyelin (L/S) ratio, the GCS and palmitic acid had the highest concurrence (84% agreement), followed by the shake test (82%), cortisol (74%), cytology (64%), gestational age determined by ultrasound (63%) and creatinine (47%). The GCS correlate better than cortisol alone, probably because cortisol in amniotic fluid is derived from the chorionic membrane as well as from fetal urine. Convincing evidence was provided of a physiologic link between fetal lung maturation and alteration in fetal steroid production.