Results from a recent study published online in the American Journal of Clinical Nutrition show that obese women are twice as likely as women with a healthy weight to have stillborn babies for specific and possibly preventable medical reasons.
The study conducted by a team of researchers from the University of Pittsburgh Graduate School of Public Health also determined that hypertension and placental diseases were the most common causes of stillbirth babies among obese women.
“We’ve known for some time that obese women are more likely to have stillbirths, but this is one of the first and most comprehensive efforts to figure out why,” said lead author Lisa Bodnar, Ph.D., M.P.H., R.D., associate professor at Pitt Public Health’s Department of Epidemiology, in a news release. “Our hope is that this work can be used to better counsel women on the importance of a healthy pre-pregnancy weight and monitor them for complications during pregnancy that may threaten the survival of their fetuses.”
“This study also could be used to guide prevention efforts at a societal level,” she said. “If we can reduce pre-pregnancy obesity by even a small amount, through environmental or policy changes, we could significantly reduce the burden of stillbirth.”
Each year, worldwide there are 3.2 million stillbirths, with the United States having one of the highest stillbirth rates. Evidence from recent studies has shown that obesity may account for more stillbirths in high-income countries than advanced maternal age or smoking.
In the study, the team of researchers assessed the medical records of 658 stillbirths that occurred between 2003 and 2010 at the Magee-Womens Hospital of UPMC. The researchers defined stillbirths as cases where the baby had reached at least 16 weeks gestation and showed no evidence of life after delivery. Obstetricians were asked to review each case and each professional was assigned with a cause of the stillbirth.
Mothers were categorized as lean (underweight or normal weight ), overweight, obese or severely obese. This classification was based on the mother BMI before their pregnancy.
Results revealed that the stillbirth rate per 1,000 births varied from 7.7 for lean mother to 17.3 for severely obese mothers. Placental diseases and maternal hypertension (high blood pressure in the mother), fetal abnormalities and umbilical cord anomalies were all more likely to occur in the group of obese women.
“Obstetricians should monitor obese patients for these complications and quickly treat conditions like hypertension if they arise in order to reduce risk of stillbirth,” said senior author Hyagriv N. Simhan, M.D., professor and chief of the division of maternal-fetal medicine and medical director of obstetrical services at Magee. “However, we’d like to see these women before they even become pregnant. When a doctor has an obese patient who is considering pregnancy, she should be referred to a maternal-fetal medicine specialist who can counsel her on the benefits of losing weight before pregnancy, as well as safe approaches to weight loss.”