The ideal weight gain during pregnancy should be 1500-3000 grams in early pregnancy (12 weeks of pregnancy), then 400 grams per week (350 grams in mid-pregnancy and 500 grams in late pregnancy), and 12,500 grams at full term compared to unexpectant weight (for people with normal pre-pregnancy weight). For each pregnant woman, first calculate your pre-pregnancy body mass index BMI = weight (kg) / height (M2), according to your own BMI how much, then according to the table below to know the whole pregnancy maternal weight gain range, according to the corresponding chart below to know your weight gain range for each pregnancy week. Recommended weight gain range for pregnant women according to BMI before pregnancy (foreign information) BMI recommended weight gain range (kg) Low < 19.812.5 ~ 18.0 Normal 19.8 ~ 26.011.5 ~ 16.0 High 26 ~ 297.0 ~ 11.5 Obese >296 ~ 6.8 (…) Institution of Medicine: Nutrition during Pregnancy 1990 ) BMI (low) maternal weight management weight chart BMI (normal) maternal weight management weight chart BMI (high) maternal weight management weight chart