Women are counseled not to be too thin or too heavy before getting pregnant, and new research gives even more reason for women to watch their weight: obese pregnant women stand a much greater chance of miscarrying or burying their child before the baby’s first birthday, the study finds.
“Given the rising prevalence of obesity in the population of pregnant women, the rates of miscarriage, stillbirth and infant mortality can be anticipated to increase,” according to the study from Newcastle University in the United Kingdom, which was published this week in the European journal Human Reproduction. (More on Time.com: Toddlers’ Junk-Food Diet May Lead to Lower IQ)
Researchers studied nearly 41,000 singleton pregnancies between 2003 to 2005 at five British maternity wards. They learned that women who were obese in early pregnancy had nearly double the risk of fetal death in utero or up to one year after birth compared to women who fell into recommended weight parameters.
That’s not to say, however, that obese women are unlikely to have healthy babies. Most babies carried by most women, regardless of their size, turn out just fine, points out the study’s lead researcher, Ruth Bell, a clinical senior lecturer in the Institute of Health and Society at Newcastle University.
Although it’s preferable to reach a healthy weight pre-pregnancy, Bell sought to reassure mothers, telling the Daily Mail “that it is uncommon for fetal and infant deaths — most women deliver healthy babies despite what weight they are.” (More on Time.com: Did Homeopathic Medicine, Breast-Feeding and Veganism Kill a Baby?)
Dieting is not recommended during pregnancy, but making healthy nutrition choices is, says Bell:
“When a woman is pregnant it is not the right time for her to go on a diet as it is most important that she eats healthily, ensuring her baby gets all the essential nutrients it needs.
“What is important, however, is that women are helped and supported to achieve a healthy weight before they become pregnant or after the baby is born, as this will give the baby the best start to life.”
Obese women suffer about eight more fetal and infant deaths per 1,000 births than women who enter pregnancy at a recommended weight, according to the study. (More on Time.com: Mothers Abused in Childhood More Likely to Have At-Risk Babies)
Pre-eclampsia — pregnancy-related high blood pressure — was responsible for a greater proportion of the obesity-related deaths. But obesity was also associated with an increased risk of other conditions. Obese pregnant women are more likely to develop gestational diabetes, which manifests itself during pregnancy.
Although researchers controlled for factors including the mothers’ age, ethnicity, smoking status, socioeconomic status and the birth weight and gestational age of the babies, they did not analyze how diet, exercise, alcohol or caffeine consumption may have influenced pregnancy risks.