Women with pre-existing hypertension more likely to develop depression during pregnancy

Women with a history of high blood pressure before getting pregnant have a higher risk of depression than women who develop pregnancy-related hypertension, according to a new study.

"Depression during pregnancy is associated with postpartum depression, problems bonding with the baby, and overall, has a large and detrimental impact on both mom and baby," said lead author Wayne Katon, M.D., of the Department of Psychiatry & Behavioral Sciences at the University of Washington.

The study, which appears in General Health Psychiatry, looked at 2,398 women receiving prenatal care at an obstetrics clinic in Seattle, Washington, evaluating them for depressive symptoms and evidence of pre-existing hypertension or pregnancy-induced hypertension.

Up to 13 percent of women have some form of hypertension during pregnancy. Seventy percent of hypertension during pregnancy is due to physiological changes occurring during pregnancy and blood pressure returns to normal after delivery. Five to seven percent of pregnant women develop a life-threatening condition known as preeclampsia, a severe form of gestational hypertension, which can lead to early delivery and low birth weight. Scientists are unsure of the causes of preeclampsia.

Previous research had suggested there might be a link between depression and pregnancy-induced hypertension and preeclampsia. However, Katon's research found no link.

Instead, they found that women with hypertension before pregnancy, with or without developing preeclampsia, were 55 to 65 percent more likely to meet the criteria for significant depressive symptoms or to be taking antidepressants.

Many women who have high blood pressure prior to pregnancy also have other risk factors, including health conditions such as diabetes and obesity, noted Katon. "Depression can make adherence to interventions, such as diet, exercise and medication, for these conditions low, further putting the mother's health at risk."

The researchers noted that they did not control for obesity, which is linked to both hypertension and depression. "Obesity is an increasing problem in pregnant women and targeting these women for more intensive counseling could be a cost-effective way of reducing the risk of depression during pregnancy," commented Ernest Graham, M.D., a gynecologist at Johns Hopkins Hospital in Baltimore, Md.

"To my knowledge, very few obstetricians do any formal screening for depression during prenatal check-ups," said Katon. "They do screen for hypertension. In women with pre-existing hypertension, it is essential to screen for depression at the four month checkup, given the risk of negative birth outcomes and non-adherence to hypertension treatment."