Feb. 2, 2009 -- Could a simple blood test help predict a pregnant woman's
risk for developing
Researchers from the University of California, Irvine say that the level of
a hormone produced by the placenta around the 25th week of pregnancy may help
predict a woman's chance of developing postpartum depression.
Ilona S. Yim, PhD, and colleagues analyzed blood samples from 100 pregnant
women and found that those who had higher levels of placental
corticotropin-releasing hormone (pCRH) midway through pregnancy were more
likely to develop postpartum depression. The blood test correctly identified
75% of those who had future postpartum depression
The findings, published in the February issue of Archives of General
Psychiatry, raise the possibility that a screening test for postpartum
depression could one day become part of a woman's standard prenatal care. The
researchers envision a screening test being done the same time as a
gestational diabetes screen, which is typically performed around 24 to 28
weeks of pregnancy.
Postpartum depression can cause feelings of sadness and hopelessness that
usually begin within the first four weeks after
giving birth. It is different and more severe than the "baby blues," and
symptoms last longer.
What makes a woman more likely to develop the condition is not entirely
clear. Risk factors for postpartum depression include a history of depression
premenstrual syndrome, stress and anxiety during pregnancy, a lack of
social support, and fluctuating hormone levels.
Some research has suggested a link between pCRH and postpartum depression,
but direct evidence from observations have been lacking.
To investigate the link between pCRH and postpartum depression, Yim's team
took blood samples from each study participant at week 15, 19, 25, 31, and 37
of pregnancy and measured the levels of pCRH as well as cortisol, a stress
adrenocorticotropic hormone (ACTH), which triggers the release of
The women, each carrying one baby, were also individually screened for
depression symptoms at the last four pregnancy visits and again almost nine
weeks after giving birth.
Sixteen women developed postpartum depression symptoms by their follow-up
visit. Increased pCRH at week 25 of pregnancy was the strongest predictor of
development of postpartum depression and correctly identified most women at
"Placental CRH in this study was a moderately sensitive and specific marker
for PPD [postpartum depression] symptoms that allows for the correct
identification of 75% of women with future PPD symptoms, and at the same time
was characterized by a low misclassification rate (24%)," the researchers write
in the journal article.
Cortisol and ACTH levels did not appear to have a significant link to the
development of postpartum depression. However, some evidence suggests the surge
in pCRH during mid-pregnancy may be associated with an increase in cortisol
early in pregnancy.