Objective: The high rate of preterm births is an imposing public health issue in the United States. Past research has suggested that prenatal stress, anxiety, and elevated levels of maternal plasma corticotropin-releasing hormone (CRH) are associated with preterm delivery in humans and animals. Studies to date have not examined all three variables together; that is the objective of this paper.
Methods: Data from 282 pregnant women were analyzed to investigate the effect of maternal prenatal anxiety and CRH on the length of gestation. It was hypothesized that at both 18 to 20 weeks (Time 1) and 28 to 30 weeks gestation (Time 2), CRH and maternal prenatal anxiety would be negatively associated with gestational age at delivery. CRH was also expected to mediate the relationship between maternal prenatal anxiety and gestational age at delivery.
Results: Findings supported the mediation hypothesis at Time 2, indicating that women with high CRH levels and high maternal prenatal anxiety at 28 to 30 weeks gestation delivered earlier than women with lower CRH levels and maternal prenatal anxiety. Women who delivered preterm had significantly higher rates of CRH at both 18 to 20 weeks gestation and 28 to 30 weeks gestation (p <.001) compared with women who delivered term.
Conclusions: These findings are the first to link both psychosocial and neuroendocrine factors to birth outcomes in a prospective design.