Women with increased levels of placental corticotropin-releasing hormone in midpregnancy have a higher risk for postpartum depression, according to a study in the February Archives of General Psychiatry. Ilona S. Yim, PhD, Assistant Professor in the Psychology and Social Behavior Department at the University of California, Irvine, and colleagues recruited 100 adult women with singleton pregnancies from two southern California medical centers for a longitudinal cohort study. Blood samples were collected at 15, 19, 25, 31, and 37 weeks’ gestation and were assayed for presence of placental corticotropin-releasing hormone, cortisol, and adrenocorticotropic hormone. Participants completed the Center for Epidemiological Studies–Depression Scale (CES-D) questionnaire during the last four pregnancy visits and at postpartum. The main outcome measure was score on the Edinburgh Postnatal Depression Scale, which was administered an average of 8.7 weeks after delivery.
Corticotropin Levels and Postpartum Depression
Sixteen women developed symptoms of postpartum depression. Increased levels of placental corticotropin-releasing hormone at 25 weeks’ gestation were the strongest predictor of these symptoms, a finding that remained significant after the researchers controlled for prenatal depressive symptoms. No significant associations were observed regarding cortisol and adrenocorticotropic hormone levels. Growth curve analysis showed that trajectories of placental corticotropin-releasing hormone in women with postpartum depression symptoms were significantly accelerated from 23 to 26 weeks’ gestation. Inclusion of CES-D scores at 25 weeks’ gestation accounted for 7% additional variance, while the influence of other variables was not significant.
Placental corticotropin-releasing hormone level remained a significant and independent predictor of postpartum depression after the addition of CES-D scores into a hierarchical linear regression analysis. “This further indicates that placental corticotropin-releasing hormone and CES-D scores explain different portions of the variance in the risk of developing postpartum depression symptoms,” Dr. Yim and colleagues stated.
The researchers suggested that the combination of both placental corticotropin-releasing hormone and CES-D markers would be an effective strategy for identifying women at risk for postpartum depression. Because hormone levels are an independent measure, consideration of placental corticotropin-releasing hormone level may help clinicians identify women at risk for developing postpartum depression, regardless of their willingness to disclose their symptoms in a self-report, the investigators noted.
“At a critical period in midpregnancy, placental corticotropin-releasing hormone is a sensitive and specific early diagnostic test for postpartum depression symptoms,” Dr. Yim and colleagues concluded. If the results are replicated, screening for placental corticotropin-releasing hormone levels and postpartum depression may be a useful addition to standard prenatal care. “In addition, a better understanding of the role of placental corticotropin-releasing hormone in the pathophysiologic mechanism leading to postpartum depression may contribute to the development of preventions targeted at this rather common disorder.
—Laura Sassano