Preterm birth: Associated neuroendocrine, medical, and behavioral risk factors

Increased CRH secretion by the placenta of pregnant women has been associat ed with preterm birth. Certain indices of risk, both medical and psychosoci al in nature, have been linked to preterm delivery. Levels of total, bound, and free CRH, CRH-binding protein (CRH-BP), and cortisol were measured pro spectively in a large sample of pregnant Danish women who delivered preterm and term infants. Measures of maternal serum hormones were taken at 7-23 a nd 27-37 weeks gestation and, for those who delivered at term, at 37-43 wee ks gestation. At 7-23 weeks gestation, maternal levels of total CRH (P = 0. 01), bound CRH (P = 0.03), and CRH-BP (P = 0.01) were higher in the preterm than in the term group. At 27-37 weeks gestation, levels of total CRH (P < 0.0001), bound CRH (P < 0.0001), free CRH (P < 0.0001), and cortisol (P < 0.0001) were all higher in the preterm than the term group, whereas levels of CRH-BP (P < 0.0001) were lower in the preterm than in the term group. Th e best medical and behavioral factors associated with preterm delivery were , respectively, previous preterm delivery (P < 0.0001) and engagement in ce rtain risk-taking behaviors (P = 0.008). The positive relations between pre term delivery and various adverse medical and socioeconomic variables with increases in placental secretion of CRH suggest that the latter may partici pate in the pathophysiology of preterm delivery.