Figure. Major Birth Defects in Infants Born to Women With Gastric Bypass Surgery and Matched Controls.

Matched controls: exact matching by maternal presurgery body mass index and diabetes (early-pregnancy body mass index and preconception diabetes used for controls), history of major birth defects in previous pregnancies, delivery year, and a propensity score based on maternal age, alcohol and substance use, smoking, parity, psychiatric drug use, and number of prescription drugs. For first birth after gastric bypass surgery, restriction was performed to avoid clustering effects (13% of mothers had >1 birth after surgery). Weights from coarsened exact matching were used to account for different sizes of matching strata.