Pregnancy Weight Gain Calculator

IOM guidelines by pre-pregnancy BMI: Underweight (<18.5): 28-40 lbs. Normal (18.5-24.9): 25-35 lbs. Overweight (25-29.9): 15-25 lbs. Obese (30+): 11-20 lbs. Gaining in the recommended range is associated with better outcomes for both mother and baby.

At delivery: Baby 7-8 lbs, Placenta 1-2 lbs, Amniotic fluid 2 lbs, Breast tissue 2 lbs, Uterus growth 2 lbs, Blood volume increase 3-4 lbs, Fluid retention 4 lbs, Fat stores 5-9 lbs. Total: 25-40 lbs for a normal-weight woman.

Excessive weight gain increases risks of: gestational diabetes, preeclampsia, large baby (macrosomia) making delivery harder, cesarean section, difficulty losing weight after delivery. It also increases the baby risk of childhood obesity. Gaining within guidelines benefits both mother and child.

Mild weight loss in the first trimester is common due to morning sickness and nausea — generally not concerning. However, significant weight loss (5+ lbs) in the first trimester should be discussed with your healthcare provider. The baby draws nutrients from your body regardless, but severe morning sickness (hyperemesis gravidarum) may require medical treatment.

First trimester: 1-4 lbs total is typical. Second trimester: about 1 lb per week. Third trimester: about 1 lb per week. This is a general guide — every pregnancy is different. Individual variation is normal. What matters most is the total gain, not week-to-week fluctuations.