If you weight 122 lb, you should gain approximately:
25-35 lbs if your weight before pregnancy was within the normal range (BMI 18.5-24.9);
15-25 lbs if before pregnancy you were overweight (BMI 25-29.9);
11-20 lbs if before pregnancy you were obese (BMI 30 and more); and
28-40 lbs if before pregnancy you were underweight (BMI less than 18.5).
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