Weight gain in pregnancy: recommended ranges and a judgement-free view

The number on the scale leaves some people curious and others uneasy in pregnancy. Yet gaining weight is a natural part of pregnancy, and every body does it at its own pace. This article walks through the ranges, where the weight goes and a calmer way of looking at the scale, without judgement.

Where does the weight you gain go?

Only part of the weight gained in pregnancy is body fat. The rest is directly linked to the pregnancy:

• Your baby’s weight
• The placenta and the amniotic fluid around your baby
• The growing womb and breast tissue
• Increased blood volume and body fluid
• Energy stores for birth and breastfeeding

We do not give exact figures for each item because they vary from person to person and week to week; what matters is knowing that most of the weight serves you and your baby.

General recommended ranges

The US Institute of Medicine (IOM) and ACOG use these ranges for single-baby pregnancies, based on pre-pregnancy body mass index (BMI):

• Underweight (BMI below 18.5): about 12.5–18 kg
• Normal weight (BMI 18.5–24.9): about 11.5–16 kg
• Overweight (BMI 25–29.9): about 7–11.5 kg
• Obese (BMI 30 and above): about 5–9 kg

These are general guides for total gain across the whole pregnancy, not strict targets. With twins or triplets the ranges are different and are set individually by your doctor; in that case, rely on your doctor’s advice alone.

How does the gain spread over time?

In most people gain is small in the first trimester; with nausea, weight may stay the same or dip slightly. In the second and third trimesters gain becomes more noticeable. Small ups and downs from week to week are common; it is the overall trend that matters, not a single reading. Even between morning and evening the scale can differ because fluid balance shifts during the day.

Weighing yourself: how often and how?

Being weighed at check-ups is to follow the trend and offer support when needed. If you would like to weigh yourself at home, once a week is enough; using the same day, same time (for example in the morning before breakfast), the same scale and similar clothing makes comparisons meaningful. If the scale makes you anxious, you can choose not to weigh at home and leave monitoring to appointments; that is a perfectly valid choice.

A judgement-free view

Comparison easily turns into stress when it comes to weight. Someone gaining less or more than another person says nothing about how your pregnancy is going. The changes in your body are part of your baby growing, and there may be days when the mirror or scale is hard; it is okay to share that feeling.

Very restrictive diets are not recommended in pregnancy. On the other hand, gaining a great deal may make some health conditions more likely. So the middle path, balanced eating and moderate activity, is usually the most comfortable. For details on eating, see the Guide article on balanced eating in pregnancy.

Gaining very fast or very little

If gain is clearly above the expected range, your doctor can review your eating and activity habits with you; this is a chance to plan together, not a reproach. If gain is clearly low, the reasons are explored: poor appetite, ongoing nausea, stress or something else. In both cases, talking at a check-up is better than deciding alone.

Sudden weight gain and swelling: take note

A sudden weight gain over a few days, especially with marked swelling of the face and hands, can be a sign of a condition linked to high blood pressure in pregnancy (pre-eclampsia). Mild ankle swelling in the evenings is common in pregnancy, but swelling that is sudden, widespread or comes with pain or headache should be assessed without waiting.

Weight after birth

After birth some weight goes right away (baby, placenta, fluid), but in most people the rest comes off gradually over months. How long varies a great deal and is affected by breastfeeding, sleep, activity and eating. Your body changed over nine months, and coming back can take time too. In the first weeks, putting recovery and nourishment first rather than weight loss is usually healthier; the article on postpartum nutrition may help.

10 quick tips that really help

1. Know your starting point: Share your pre-pregnancy weight and height with your doctor so the right range becomes clear together.
2. Look at the trend: Follow the course over weeks rather than a single reading.
3. Weigh at most once a week: Same day, same time, same scale.
4. Build balanced meals: Put vegetables, protein and wholegrains on your plate.
5. Try small, frequent meals: During nausea, focus on what you can eat comfortably rather than on weight worries.
6. Cut back on sugary drinks: Without restricting yourself, choose water or ayran more often.
7. Add gentle movement daily: Unless your doctor advises otherwise, walking suits most people.
8. Stop comparing: Numbers on social media or around you do not describe your journey.
9. Share how you feel: If you struggle with your body image, open up to your midwife, doctor or someone you trust.
10. Be patient after birth: A change that took nine months does not have to reverse in a few weeks.

When to contact your doctor

• If you gain weight very quickly and notice sudden swelling, especially of the face and hands.
• If you have a severe headache, blurred vision, flashing lights or upper abdominal pain; these may need urgent assessment, so call 112 (in Turkey) or your local emergency number or go to the nearest emergency department.
• If you have marked weight loss from early pregnancy or cannot keep anything down because of nausea.
• If your gain is clearly below expected or does not rise over several check-ups.
• If you have twins or more, or a condition such as gestational diabetes, and want to know your goal.
• If you feel intense anxiety or loss of control around food or weight, or have had an eating disorder in the past.

Frequently asked questions

How much weight should I gain in pregnancy? It depends on your pre-pregnancy BMI. The ranges above are general guides; ask your doctor about your own goal.

Is it a problem if I lose weight in the early months? Small losses in the first trimester due to nausea and poor appetite are seen in many people. Tell your doctor if the loss continues or you cannot eat anything.

How often should I weigh myself at home? Once a week is enough, at the same time and with the same scale. If it makes you anxious, you can choose not to weigh at all.

I have gained a lot. What should I do? Do not blame yourself or start a sudden diet. Review eating and activity together with your doctor.

When will the weight come off after birth? It varies; for most people it takes months. Breastfeeding, sleep and eating all play a part.

My gain is low. Will my baby grow enough? Your baby’s growth is monitored with ultrasound and check-ups. If you are worried, talk to your doctor.

This article is for information only; your doctor or midwife will work out with you the weight gain that suits you.