Team links placental hormone spike to postpartum depression

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Findings of a new study could help in early identification of mothers at risk for postpartum depression.

Researchers have found evidence of a potential link between patterns of changes in a key pregnancy hormone called 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.

“One in 5 women report experiencing elevated depressive symptoms within the year after giving birth,” says lead author Isabel F. Almeida, assistant professor of Chicano/Latino studies and director of the Latina Perinatal Health Lab at the University of California, Irvine.

“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.”

For the study, the researchers followed 173 US 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 postpartum depression 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 says.

“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:

  • Typical (50.9%), characterized by moderate, expected increases in pCRH levels.
  • Flat (23.7%), showing low levels of pCRH and the least change across pregnancy. Women in this group were significantly younger and less likely to identify as Asian, be married, or have completed college compared to those in the other groups.
  • Accelerated (25.4%), indicating the highest levels of pCRH and steepest increase from mid- to late-stage pregnancy. Women in this group had markedly higher income and lower pre-pregnancy body mass index.

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.

The results suggest that pCRH trajectories may influence postpartum depression symptoms, Almeida says.

“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.”

Additional coauthors are from UCLA and the University of Colorado Colorado Springs.

The National Institute of Mental Health Biobehavioral Issues in Mental and Physical Health Program, a UCI Chancellor’s ADVANCE Postdoctoral Fellowship, and a Eugene V. Cota-Robles Fellowship funded the work.

Source: UC Irvine