Prepregnancy Weight and the Risk of Adverse Pregnancy Outcomes

Obesity before pregnancy is associated with an increased risk of fetal macrosomia and perinatal mortality. 1 – 3 The mother's being leaner than average (underweight), on the other hand, is associated with an increased risk of delivering an infant who is small for gestational age and perhaps also the risk of preterm delivery. 3 – 6 Pregnancies among underweight or overweight women are therefore often regarded as high-risk pregnancies, and thin women are frequently advised to gain weight before becoming pregnant. 7 , 8 Nonetheless, the optimal weight or body-mass index for women who wish to become pregnant is not known. 7 – 9 The Swedish Medical Birth . . .