Blood Test May Predict Postpartum Depression

Measuring hormone could find three-fourths of women at risk, study claims

MONDAY, Feb. 2, 2009 (HealthDay News) -- Measuring the levels of a hormone produced by the placenta during pregnancy might predict whether a woman is likely to develop postpartum depression, a new study suggests.

Approximately 13 percent of women will experience postpartum depression, a condition that holds significant consequences not only for women but for their infants and families as well, experts say. Once a woman has had postpartum depression, she is more likely to have future bouts of depression, and that puts infants and children at risk for cognitive, behavioral and social problems.

"If we know early on that a woman is at high risk to develop postpartum depression, then we can implement interventions before symptoms actually occur," said lead researcher Ilona S. Yim, an assistant professor of psychology at the University of California, Irvine.

"By means of a simple blood draw, we could correctly identify 75 percent of women who would later develop postpartum depression," she said.

The report is published in the February issue of Archives of General Psychiatry.

For the study, Yim's group looked for a link between placental corticotropin-releasing hormone (pCRH) and postpartum depression. The researchers took blood samples from 100 pregnant women at various stages during their pregnancy and tested for levels of pCRH.

They also assessed the women for signs of depression during pregnancy and about eight weeks, on average, after delivery.

In all, 16 women developed postpartum depression. In each case, the women had had high levels of pCRH at 25 weeks into their pregnancies, the study found.

The blood test, which was found to have a high degree of both specificity and sensitivity, could identify about 75 percent of women who would develop postpartum depression, Yim's team found. The test misclassified about 25 percent of the women.

When the blood test was combined with assessing symptoms of depression during pregnancy, Yim noted, it was even more predictive of postpartum depression.

If the findings can be replicated, then testing the level of this hormone might become standard care, Yim said.

"Postpartum depression affects so many women that it would be great to have something that would help to identify being at risk early on, and perhaps develop strategies to prevent it," she said.

Women who know they are at risk for postpartum depression can take steps to reduce stress that might ward off the condition, Yim said. "They could take yoga classes and avoid severe stressors," she said.

Postpartum depression generally begins within four to six weeks after delivery. Risk factors include a history of depression, stressful life events, a lack of social support, low self-esteem and depression, anxiety or stress during pregnancy.

Postpartum depression expert Jeanelle Sheeder, a clinical sciences senior instructor of obstetrics and gynecology and pediatrics at the University of Colorado Medical Center in Denver, said she was not sure that the blood test would add more than what can be gleaned from screening women for signs of depression before and during their pregnancies.

"It is encouraging to have a prenatal biologic measure that predicts postpartum depression," Sheeder said. "However, I am not sure about the practicality of using pCRH as a screening tool. It has been shown that prenatal depression is predictive of postpartum depression, and it is easier and cheaper to do that type of screening than pCRH in most clinical settings."

More information

The National Women's Health Information Center has more on depression and pregnancy.

SOURCES: Ilona S. Yim, Ph.D., assistant professor, psychology, University of California, Irvine; Jeanelle Sheeder, M.S.P.H., clinical sciences senior instructor, obstetrics and gynecology and pediatrics, University of Colorado Medical Center, Denver; February 2009 Archives of General Psychiatry
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