A University of Pittsburgh study found that obese women are twice as likely to have a stillborn baby as women with healthier body mass indices.
Lisa Bodnar, associate professor of epidemiology, said many studies have shown the increase risk of stillbirth among women who begin a pregnancy while obese, but she wanted to understand why that happened and what could prevent it.
With her colleagues, she examined seven years of recorded stillbirths at Magee-Womens Hospital of UPMC. A panel of physicians then categorized those 658 stillbirths by the mother’s weight.
They found the higher the mother’s body mass index, the higher the rate of stillbirth.
Bodnar said high blood pressure – or hypertension – and placental disease were the most common causes of stillbirth among obese women.
“The placenta is there to sustain unborn baby, and what we found is that conditions that prevent adequate blood flow to the baby are ones that are related to stillbirths in these obese mothers,” she said.
By eliminating other factors for stillbirth, Bodnar found that the two most common causes of stillbirth were related to obesity because of the lack of adequate blood flow to the fetus.
“Many women who have hypertension also have problems with their placenta and what we found is that even if you remove the women who had hypertension there was still this independent relationship between obesity and placental diseases,” she said.
Bodnar said if women are considering pregnancy they should see a maternal fetal medicine specialist to understand the benefits of losing weight before pregnancy.
But many times women have unplanned pregnancies, she said, and don’t receive pre-conception care.
“Another important implication of the findings is that obstetricians who monitor women with obesity during pregnancy need to have a careful eye for these complications and quickly treat the conditions like hypertension if they arise in order to reduce the risk of stillbirths.”
Anti-hypertensive medicines and regular blood pressure monitoring would be put in place if a physician spotted these potential complications.
Bodnar said the results suggest even small changes in weight prior to pregnancy could reduce stillbirths. But, she said, the blame can’t be placed on just the mother.
“We can’t rely exclusively on asking women to change their diets and change their lifestyles," Bodnar said. "We have something to do as a society to help promote healthy weight in our country.”