Ever see a super slim pregnant woman, and feel a pang of jealousy? Well, a new study published in the American Journal of Public Health might change that.
Researchers at the University of Maryland looked at over 159,000 women over the course of four years, noting how much weight they gained during pregnancy in comparison to the rates of infant mortality. It turns out, women who didn’t gain enough weight were more likely to lose their baby within the first year of birth, compared to those who put on more pounds.
Obviously, no woman wants to put her baby at risk, but remember that the study can't prove causation—it's just an association for now. Still, if you're actively trying to stay slim during pregnancy, the research does suggest a big reason not to: The infant mortality rate among mothers who didn’t gain enough weight was 3.9 percent, compared to 1.2 percent among infants of mothers who gained the suggested amount of weight, and 0.7 percent among those who gained too much.
The importance of putting on the pounds.
So, what might be going on? Researchers also looked at the infant’s death certificates, and found that the most common cause of death was fetal malnutrition, ultimately resulting in birth defects and respiratory problems.
“Today, there’s a lot of concern around remaining slim during pregnancy, but it’s a trade off for the baby,” says Sandra Hofferth, PhD, professor in the Department of Family Science at University of Maryland, and lead researcher of the study. “You need to consume enough calories in order for your baby to develop adequately, and they need to be high quality calories.” (Read: Not from a drive thru.)
How much should you gain?
Check out our BMI Calculator to determine the optimal amount of weight for you, based on your body mass index, and ask your doctor if you’re gaining a healthy amount throughout your pregnancy.
Worth noting: You don’t want to gain too much weight, either. “Even though our study showed less risk of infant mortality for mothers who gained an excessive amount of weight, too many extra pounds are harmful to the mother,” says Dr. Hofferth. (Excessive weight gain could cause heart problems, gestational diabetes, and hemorrhaging.) Remember: You really only need an extra 300 calories per day, per baby.