Placental hormone spike in late pregnancy linked to postpartum depressive symptoms

A University of California, Irvine-led team has found evidence of a potential link between patterns of changes in a key pregnancy hormone—placental corticotropin-releasing hormone—and symptoms of postpartum depression.

The findings, published in Psychoneuroendocrinology, add to a growing body of research on physiological risk factors during pregnancy tied to adverse postpartum outcomes and could aid in the early identification of at-risk mothers.

“One in five women report experiencing elevated depressive symptoms within the year after giving birth,” said lead author Isabel F. Almeida, UC Irvine assistant professor of Chicano/Latino studies and director of the Latina Perinatal Health Lab.

“Symptoms of depression following the birth of a child can have adverse effects for mothers, children and families, so it’s vitally important that we work to understand the causes.”

Co-authors include Gabrielle R. Rinne, a UCLA health psychology Ph.D. student; Christine Dunkel Schetter, a Distinguished Research Professor of psychology at UCLA; and Mary Coussons-Read, a psychology professor and department chair at the University of Colorado Colorado Springs.

The study followed 173 U.S. women of various income and education levels as well as racial and ethnic backgrounds (non-Latina white, Latina/Hispanic, Black and Asian) throughout pregnancy and the year after childbirth.

Blood samples were taken at three prenatal visits—one at eight to 16 weeks’ gestation, one at 20 to 26 weeks’ gestation and one at 30 to 36 weeks’ gestation—and a 10-item questionnaire was administered at one, six and 12 months postpartum to track the occurrence and degree of depressive symptoms.

“Previous studies have focused on a singular point in time to assess [placental corticotropin-releasing hormone] levels, whereas our work characterized comprehensive changes in pCRH across pregnancy to clarify links with postpartum mental health,” Almeida said. “This person-centered approach was key, as it allowed us to identify and compare subgroups of individuals and their trajectories at a more granular level over pregnancy alongside postpartum data.”

Earlier work has shown that pCRH levels increase exponentially throughout pregnancy, and blood samples taken by the researchers were consistent with these patterns. But there was variability in individual ranges of pCRH, particularly between mid- and late-stage prenatal levels. Specifically, women fell into one of three groups:

Across the study, 13.9% of participants reported depressive symptoms one month postpartum, with women in the accelerated group recording marginally higher depressive symptoms than those in the typical and flat groups.

Almeida said the results suggest that pCRH trajectories may influence postpartum depressive symptoms. “Our findings highlight the dynamic physiological changes that occur during pregnancy and elucidate how such changes relate to postpartum health.

“Future work should further explore how changes in stress response in the hypothalamic-pituitary-adrenal axis are related to postpartum depressive symptoms, focusing specifically on patterns of change in pCRH.”