Health

Pregnancy weight gain by trimester: what is a healthy range?

A healthy weight-gain target depends mainly on your pre-pregnancy BMI, whether you carry one baby or multiples, and your individual health. For a singleton pregnancy, US guidance recommends a total of 12.7–18.1 kg if underweight, 11.3–15.9 kg at a healthy BMI, 6.8–11.3 kg if overweight and 5–9.1 kg with obesity. Local recommendations may differ.

Pregnant woman discussing healthy weight gain with a maternity clinician

Written by HelloMommy editorial teamUpdated August 27, 20262 min read

Healthy total ranges for one baby

CDC ranges are: BMI below 18.5, 12.7–18.1 kg (28–40 lb); BMI 18.5–24.9, 11.3–15.9 kg (25–35 lb); BMI 25–29.9, 6.8–11.3 kg (15–25 lb); BMI 30 or above, 5–9.1 kg (11–20 lb). These are guides, not pass-or-fail targets.

First trimester

Weight change is often small: around 0.5–2 kg (1–5 lb) in total, and some people gain nothing. Nausea can cause temporary loss. Persistent vomiting, dehydration or ongoing weight loss needs medical help rather than pressure to meet a chart.

Second and third trimesters

Gain is usually steadier after week 13. At a healthy pre-pregnancy BMI, guidance often averages about 0.23–0.45 kg (0.5–1 lb) weekly. Suggested rates are lower at higher BMI and higher if underweight; your clinician should personalise the trajectory.

What the weight includes

Pregnancy gain includes the baby, placenta, amniotic fluid, increased blood and body fluids, breast and uterine tissue and energy stores. Daily scale changes can reflect fluid, meals and bowel habits, so the trend is more useful than one reading.

Supporting a healthy pattern

Eat regular balanced meals with vegetables, fruit, whole grains and protein, and stay active if medically safe. Extra calorie needs are usually minimal in the first trimester and rise later. Pregnancy is not the time for crash diets or unsupervised weight loss.

Frequently asked questions

How much weight should I gain in the first trimester?

Many people gain about 0.5–2 kg (1–5 lb) or none. Your pre-pregnancy BMI, symptoms and baby’s growth matter more than a single number.

Is the same range right for twins?

No. Multiple pregnancies use different, generally higher ranges. Ask your maternity team for an individual target.

Should I lose weight while pregnant if my BMI is high?

Do not start a restrictive weight-loss plan without specialist advice. Focus on nutrition, safe activity and fetal growth with your clinician.

Sources

This article is for general information only and is not medical advice. Always talk to your doctor or midwife about your own pregnancy.