How much weight should I gain during pregnancy?

It depends on your pre-pregnancy BMI. For normal weight (BMI 18.5-24.9), the IOM recommends gaining 11.5-16 kg (25-35 lbs) total.

How much weight is gained per trimester?

In the first trimester, gain is 0.5-2 kg. In the second and third trimesters, gain is steadier: about 0.35-0.50 kg per week for normal-weight women.

Is gaining too much weight dangerous?

Yes, excessive gestational weight gain is associated with gestational diabetes, preeclampsia, cesarean delivery, and complications. Always consult your doctor.

Pregnancy Weight Gain Calculator | Calcufast

How Much Weight Should You Gain During Pregnancy?

Weight gain during pregnancy is normal and necessary for your baby's healthy development. However, gaining too much or too little can lead to complications.

IOM (Institute of Medicine) Guidelines

The U.S. Institute of Medicine published the most widely used guidelines for gestational weight gain in 2009:

Recommendation by pre-pregnancy BMI

| Pre-pregnancy BMI | Category | Total recommended gain | |---|---|---| | Below 18.5 | Underweight | 12.5 - 18.0 kg (28-40 lbs) | | 18.5 - 24.9 | Normal | 11.5 - 16.0 kg (25-35 lbs) | | 25.0 - 29.9 | Overweight | 7.0 - 11.5 kg (15-25 lbs) | | 30.0 or more | Obese | 5.0 - 9.0 kg (11-20 lbs) |

Weight Gain by Trimester

First trimester (weeks 1-13)

Gain is minimal: 0.5 to 2 kg total. Many women even lose weight due to morning sickness.

Second trimester (weeks 14-27)

Gain becomes steadier. Normal-weight women should gain about 0.35 to 0.50 kg per week.

Third trimester (weeks 28-40)

The rate of gain continues similarly to the second trimester as the baby grows rapidly.

Important medical disclaimer

This calculator is a guide based on IOM recommendations. Every pregnancy is different. Always consult your OB-GYN for personalized monitoring.

Where Does the Weight Go?

Not all weight gained is fat. Here's the breakdown:

Baby: 3.0 - 3.5 kg
Placenta: 0.5 - 1.0 kg
Amniotic fluid: 0.5 - 1.0 kg
Uterus: 1.0 kg
Breasts: 0.5 - 1.5 kg
Extra blood: 1.5 - 2.0 kg
Fat stores: 2.5 - 4.0 kg
Body fluids: 1.5 - 3.0 kg

In the first trimester, gain is minimal. From the second trimester onward, normal-weight women should gain 0.35-0.50 kg/week. Overweight women should gain 0.23-0.33 kg/week.

Yes, it's completely normal. Many women even lose weight in the first trimester due to nausea. What matters is the gain from the second trimester onward.

Excess gestational weight gain is linked to higher risk of gestational diabetes, preeclampsia, cesarean delivery, and difficulty losing weight postpartum. Consult your doctor.

Insufficient gain may be associated with low birth weight and premature delivery. Maintain nutritious eating habits and consult your doctor.

Yes. For twins, the IOM recommends more: 16.8-24.5 kg for normal weight, 14.1-22.7 kg for overweight, and 11.3-19.1 kg for obese women.