Weight gain recommendations are based on pre-pregnancy BMI and apply to single pregnancies. Gaining within recommended ranges supports the baby's health and makes postpartum weight loss easier. First trimester: minimal gain (about 1–2 kg). Second and third trimesters: steady gain of about 0.4–0.5 kg/week for normal BMI. For twins, the IOM/CDC ranges are higher — roughly 17–25 kg (37–54 lbs) for normal weight, 14–23 kg (31–50 lbs) for overweight, and 11–19 kg (25–42 lbs) for obesity; there is not enough evidence for a firm underweight twin recommendation. Pregnancy is generally not a time for intentional weight loss, even at higher BMIs. Consult your healthcare provider for personalized guidance. This information is for general reference and is not medical advice.
Frequently Asked Questions
Q: Which BMI does this chart use?
A: Your pre-pregnancy BMI, calculated from your weight before becoming pregnant. The recommended total gain decreases as pre-pregnancy BMI increases.
Q: How much weight gain is normal in the first trimester?
A: Often only about 1–2 kg (a few pounds) total. Most of the recommended gain happens steadily during the second and third trimesters.
Q: Is it safe to try to lose weight while pregnant?
A: Pregnancy is generally not a time for intentional weight loss, even at higher BMIs. The focus is on healthy eating and appropriate, gradual gain. Always follow your provider's guidance.
SourceInstitute of Medicine / National Academy of Medicine (2009) pregnancy weight gain guidelines, as cited by the CDC and ACOG (single pregnancies).