Amniotic fluid urocortin, CRF, oestriol, dehydroepiandrosterone sulfate and cortisol concentrations at mid-trimester: putative relationship with preterm delivery

OBJECTIVE: Stress-related peptide and steroid hormones are involved in the pathogenesis of preterm delivery, even though their clinical usefulness as predictive markers of preterm delivery remains unclear. The present study evaluated whether mid-trimester amniotic fluid concentrations of stress-related peptides, that is corticothophin-releasing factor (CRF) and urocortin (Ucn) and feto-placental steroids (oestriol, DHEA-S and cortisol) correlated with preterm delivery. STUDY DESIGN: It is a retrospective case-control study. Healthy women (n=130) undergoing amniocentesis at mid-gestation for genetic indications, of whom 15 had a preterm delivery (cases) and 115 delivered at term (controls). CRF, urocortin, cortisol, DHEA-S and oestriol concentrations were measured by specific and sensitive immunoenzymatic assays. RESULTS: Amniotic fluid urocortin concentrations in the cases (0.50+/-0.07 ng/ml) (M+/-SD) were significantly lower (P<0.0001) than in the control group (0.90+/-0.26 ng/ml), while CRF concentrations did not differ between the cases (1.52+/-0.39 ng/ml) and control group (1.64+/-0.68 ng/ml). Amniotic fluid cortisol (17.71+/-3.72 ng/ml vs. 17.32+/-3.17 ng/ml), DHEA-S (0.16+/-0.06 ng/ml vs. 0.17+/-0.09 ng/ml) and oestriol (4.68+/-1.95 ng/ml vs. 4.79+/-1.84 ng/ml) concentrations were similar in the two groups. CONCLUSIONS: The low amniotic fluid concentrations of urocortin at mid-trimester may be a signal of predisposition to preterm delivery, while the unchanged CRF and steroid hormones concentrations in women delivering preterm suggest that this mechanisms are not yet activated at mid-trimester.