A large global meta-analysis found nearly 25% increase in fetal death and stillbirths per five-unit increase in maternal BMI. Being overweight or obese before becoming pregnant increased the risk of poor outcomes compared to normal-weight women. The greatest risk was for the heaviest women, and this dose-response relationship suggests underlying biological mechanisms. The optimal pre-pregnancy BMI and and any threshold effects are yet to be determined.
PositiveTip: Planning a pregnancy? Keep those extra pounds off for the health of your baby and yourself.