Weight and Pregnancy Being either underweight or overweight when you become pregnant can put you at risk for certain pregnancy complications. Babies born to underweight moms can be born prematurely or at low birthweight, which puts them at risk for health and development problems. Infants born to moms who are overweight can develop diabetes and high cholesterol. Getting to the ideal weight can be as simple as upping your nutrition game. Eating healthy meals is important for both you and your developing baby. Here are the pregnancy weight gain recommendations, based on your weight (BMI) coming into pregnancy: Normal weight: 25 to 35 pounds Underweight: 28 to 40 pounds Overweight: 15 to 25 pounds Obese: 11 to 20 pounds Just how much weight you should gain during your pregnancy depends on your BMI (body mass index) prior to pregnancy. Talk about your specific numbers with your doctor or midwife to ensure smooth sailing.