Genes May Boost Woman's Risk of Postpartum Depression
Test found specific changes to two genes predicted problem with 85 percent accuracy
Kaminsky acknowledged that if a blood test result actually caused distress for an expectant mom, it would not be good. But, he said, having a blood test as an option for women who want an idea of their risk could be valuable.
Kaminsky and two of his co-researchers have filed for a patent on testing for the genetic markers.
The findings are based on 51 pregnant women with a history of depression or bipolar disorder, which raises the risk of suffering depression during or after pregnancy. One group of 19 women had major depression during their pregnancies, and 12 continued to have symptoms in the first month after giving birth.
Another 32 women were depression-free during pregnancy, but 11 developed postpartum depression.
Based on research with mice, Kaminsky's team suspected that estrogen triggers so-called epigenetic changes in genes in the brain's hippocampus. With epigenetic changes, there is no defect in the underlying DNA, but a gene's activity is altered. The results of research conducted in mice, however, often are not able to be replicated in humans.
The researchers found that epigenetic changes in the TTC9B and HP1BP3 genes were predictive of a woman's risk of postpartum depression.
Yonkers said one theory has been that women who develop postpartum depression may respond differently to the big shifts in estrogen and other hormones that happen during pregnancy and after childbirth.
Kaminsky said the new findings give some insight into that hormonal response. But he said more research is needed to really understand what's going on.
The results also need to be confirmed in a larger, more diverse group of women, Kaminsky said. "The women in this study all had been previously diagnosed with depression or bipolar disorder," he said. "We really need to look at this in a general population of women too."
In general, experts suspect that many factors come together to cause postpartum depression, including a woman's particular circumstances, such as whether she has a good "support network," if she has other major stressors in her life or whether the pregnancy was planned or not.