What Pregnancy Weight Gain Is, and Why It Matters

Gaining much more or much less than the recommended range is linked to complications for both parent and baby, including gestational diabetes, high blood pressure and a baby who is born small or large.

Key takeaways

• Underweight before pregnancy (BMI under 18.5): 28 to 40 lb (about 13 to 18 kg)
• Healthy weight (BMI 18.5 to 24.9): 25 to 35 lb (about 11 to 16 kg)
• Most useful single change: Ask at your first visit what your target range is.
• Commonest mistake: "Eating for two" in the sense of doubling portions.
• See a doctor if any of the signs under "When to speak to a doctor" below apply to you.

The short answer

The recommended range of weight gain across pregnancy, which depends on your BMI before you became pregnant.

Where it fits

This is part of Pregnancy. Guidance sets out what to look for and what to do about it, which is what the rest of this page covers.

The numbers, in one place

What that means in practice

In everyday terms:

• Ask at your first visit what your target range is
• Track your weight at each prenatal visit rather than daily
• Get the extra calories from nutrient-dense foods: whole grains, beans, dairy, lean protein, fruit and vegetables
• Stay active; guidelines recommend about 150 minutes of moderate activity a week in pregnancy if your provider agrees

What gets people into trouble

The mistakes that come up again and again:

• "Eating for two" in the sense of doubling portions
• Dieting to lose weight during pregnancy unless your care team advises it
• Comparing your gain to someone else's, since ranges depend on your starting BMI

Related topics

• Body Mass Index: Sorting the Evidence From the Noise (Weight Management)
• What the Guidance Really Says About Vaccination in Pregnancy (Vaccinations)
• Listeria in Pregnancy: What Published Guidance Supports (Food Safety)
• Type 2 Diabetes: Sorting the Evidence From the Noise (Diabetes)

Where to go next

• Pregnancy Weight Gain at a Glance
• The Evidence on Pregnancy Weight Gain, Without the Hype
• Pregnancy Weight Gain — the reference entry
• Pregnancy and Postpartum: The Complete Guide
• Gestational Diabetes: Sorting the Evidence From the Noise
• What the Guidance Really Says About Preeclampsia Warning Signs

When to speak to a doctor

Tell your prenatal care provider about sudden weight gain, especially with swelling of the face or hands, or about weight loss or being unable to keep food down, since these can signal preeclampsia or severe nausea and vomiting. Call 911 for chest pain, trouble breathing or fainting.

Where this comes from

• CDC — Weight Gain During Pregnancy
• American College of Obstetricians and Gynecologists — Nutrition During Pregnancy
• Office of Disease Prevention and Health Promotion — Physical Activity Guidelines for Americans

How this page was put together

Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.

Medical disclaimer

This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.