How Many Kgs Will Increase During Pregnancy​?

You step on the scale at your antenatal visit, and the number jumps up. Now you wonder if that is too fast, too slow, or alright. One of the questions every mom-to-be asks is, ‘How many kgs will I gain during pregnancy?’ The honest answer is, “It is contingent upon where you started.” So let’s analyse the numbers, where these kgs go, and what Indian research has to say about weight gain during pregnancy.

Quick Answer: How Many Kgs Will Increase During Pregnancy?

Your target is based on your pre-pregnancy body mass index (BMI). The Institute of Medicine (IOM) guidelines, as reaffirmed by ACOG, are widely used for one baby—

Pre-pregnancy BMI	Category	Total gain (kg)
Below 18.5	Underweight	12.5 to 18
18.5 to 24.9	Normal	11.5 to 16
25 to 29.9	Overweight	7 to 11.5
30 or above	Obese	5 to 9

Most women with a normal BMI are between 11.5 and 16 kg. If you are a smaller woman, try to put on a bit of weight, and if you are a heavier woman, try to lose a bit of weight. The table is a starting point – your doctor sets the final goal.

How to Find Your Pre-Pregnancy BMI

BMI is your weight in kilograms divided by the square of your height in metres. Here is a worked example:

1. Take your weight pre-pregnancy, say 55 kg.
2. Suppose you are 1.55 m tall.
3. Square the height: 1.55 * 1.55 = 2.4025.
4. Divide: 55 / 2.4025 = about 22.9.

A BMI of 22.9 is in the normal range, and the target is 11.5-16 kg. If you cannot recall your weight before pregnancy, use your weight at the first visit to the antenatal clinic. ACOG says doctors should calculate your BMI at your first prenatal visit and advise you on appropriate gain.

Where Does the Weight Go?

Many pregnant women think the extra kgs are all fat. They aren’t. Here’s what a sample breakdown looks like at full term for an average woman:

• Baby: approx. 3.5 kg
• Amniotic fluid: around 0.9 kg
• Placenta: 0.7 kilos (1.5 pounds)
• Uterus size: 0.9 kg (approx.)
• Breast growth: ~1 kg
• Extra blood: around 1.5 kg
• Additional body fluids: about 1 to 1.4 kg
• Stores of fat and nutrients: about 2 to 3.5 kg

The baby typically makes up just over one-third of the weight you gain. The rest is a support mechanism that your body develops. Your blood volume increases by about 50 per cent, for example, and alone that adds some 3 kg of blood and body fluids. So a 12 kg gain is not 12 kg of fat. At the time of delivery, most of it is lost with the baby, the placenta, and the fluids.

Trimester-by-Trimester Weight Gain

Progress was slow at first, then faster. The IOM guidelines assume you will actually gain 0.5-2 kg in the first trimester. Your BMI group then determines your weekly rate:

Pre-pregnancy BMI group	Weekly gain in 2nd and 3rd trimesters
Underweight	about 0.51 kg (0.44 to 0.58)
Normal	about 0.42 kg (0.35 to 0.50)
Overweight	about 0.28 kg (0.23 to 0.33)
Obese	about 0.22 kg (0.17 to 0.27)

This is the maths for a mum with a normal BMI. Week 14 to week 40 is 26 weeks. That’s 11 kg or so at 0.42 kg a week. Then you add 0.5 to 2 kg from the first trimester, and you get to around 11.5 to 13 kg. That falls within the 11.5 to 16 kg range.

Don’t panic if week one isn’t a change week. Gains move in steps and not in a straight line. Check the trend over a month.

What Affects Your Weight Increase During Pregnancy

There are a number of things that can move your target up or down.

• Your initial BMI. This is the biggest factor, as the tables show.
• Twins or more. The IOM has provisional advice for a woman of normal weight of 16.8 to 24.5 kg for twins. The range will be decided by your doctor.
• Morning sickness. Nausea and vomiting may retard early gain. Many mums start to pick up the pace again in the second trimester.
• Diet & Activity. What you eat and how much you move affect the gain between visits.
• Your body’s own pattern. Two women who have the same BMI can gain differently. That’s normal.

Weight Gain Guidelines for Indian Women

Here’s something most articles don’t cover. The numbers used by the IOM are based on a Western population, and the recommendations for weight gain are in turn based on the Western WHO BMI cutoffs. So it is difficult to apply the findings to Asian Indians. WHO also recommends lower BMI cut-offs for risk in Asians than Caucasians. However, to date, Indian-specific guidelines have not been developed.

Mixed results are found in research from India:

A systematic review showed that most pregnant Indian women gain less than recommended by the IOM.

• A study of 2,728 women in Chennai found that overweight and obese women who gained more than recommended increased the risk of macrosomia (a very large baby). Obese women who gained more weight also had higher risks of preterm labour, caesarean section and pre-eclampsia.
• The same study found that women with normal weight and overweight women who gained less had a lower risk of caesarean section and macrosomia. They also had a higher risk of low birth weight and preterm birth, but the difference was not statistically significant.
• A study done in Pune in 2022 found that Indian women underweight, normal, overweight, or obese had lower weight than the international reference group in all BMI categories.
• In September 2025, the Indian Council of Medical Research (ICMR) issued a call for data to conduct a national study to develop India-specific guidelines for gestational weight gain.
• What does this mean for you? Use the IOM table as a rough guide and let your gynaecologist adjust it for your build, your diet, and your baby’s growth on scan. Chasing a number off a chart can deceive you.

Risks of Gaining Too Much or Too Little

Both extremes could be a danger.

• Too much. Excess weight gain raises the risk of high blood pressure and gestational diabetes, and the baby has a greater chance of metabolic disease later. It also makes it more difficult to lose the weight after delivery. Healthy gain prevents gestational diabetes, preeclampsia, and caesarean delivery.
• Not enough. Low gain has been linked to low birth weight, small-for-gestational-age infants, and preterm birth.
• See the pattern? It is not a race to the lowest or highest number, but a smooth middle.

Healthy Ways to Manage Your Weight Gain

This is not the time to diet during pregnancy. Dieting to manage weight is the wrong plan. Try these habits instead:

1. Eat a little more, not twice as much. According to the National Institute of Nutrition (NIN) in India, energy demand goes up by about 350 kcal a day during pregnancy. That is about one small meal more, like a bowl of dal with a chapati and a fruit, not a second full thali.
2. Have a balanced plate. Mix cereals with dal or other proteins, have vegetables and fruits in most meals, and add curd or milk.
3. Choose gentle motion. ACOG’s Committee Opinion 804 states that physical activity during an uncomplicated pregnancy is safe and advisable. Prenatal yoga and walking are favourites.
4. Weigh yourself at the same time each week or at your clinic visits. Use the same scale and similar clothes. Mention the trend to your doctor.
5. Forget crash dieting and eating for two. Both ends are blowable.
6. If you want to take classes and medical care at the same time, Mom’s Preg Ladder, founded by an internationally certified childbirth educator, Swapnil Kaushik offers trimester-specific prenatal yoga classes with gentle exercises for flexibility and relaxation. It also provides early pregnancy classes and one-on-one consultations. These are in addition to your doctor’s advice and not instead of it.

When to Call Your Doctor

If your weight shifts in a way that seems off, call your doctor. Examples include a sudden increase in weight over a few days, swelling in your face or hands, or very little weight gain over several weeks. Call, too, if you can’t keep food down. For guidance on when to take a pregnancy test, you can also refer to this resource. Do not attempt to rectify the number on your own by dieting or skipping meals.

Final Thoughts: Your Next Steps

There is no magic number for how much weight you’re supposed to gain while pregnant. There’s a range that applies to your starting BMI, your frame, and your baby’s growth. Calculate your BMI. Find out your range. Watch the trend, not the individual week’s reading. Eat a little more, take gentle exercise and bring any questions you have to your next antenatal visit.

Mom’s Preg Ladder lists its prenatal yoga, early pregnancy and consultation options for classes or a one-to-one chat with a trained educator. Be gentle with your body. It works a lot.

Frequently Asked Questions

How many kg will increase during pregnancy with a normal BMI?

If your BMI before pregnancy is between 18.5 and 24.9, the IOM and ACOG guidelines recommend gaining a total of 11.5 to 16 kg for one baby. Your doctor may change this range depending on your health and scans.

How much weight should I gain in the first trimester?

Most guidelines recommend a small first trimester gain of 0.5-2 kg. Nausea and food aversions can keep the count low or even cause a slight loss. The faster gain begins generally from the second trimester onwards;

Is it harmful to gain less than the recommended weight?

Some women may be comfortable gaining less. But low gain has been linked with low birth weight and preterm birth. Indian studies show many women gain less than the recommendations. Talk to your gynaecologist about your baby’s growth scans and your gain.

How much weight will I gain with twins?

The IOM’s provisional recommendation for a woman of normal weight is 16.8 to 24.5 kg for twins. The range is dependent on BMI. Your doctor will set a target for your own pregnancy, and you will likely have closer monitoring.

Is the baby most of the weight I gain?

No. At term, the infant weighs about 3.5 kg, one quarter to one third of the total gain. The rest is the placenta, amniotic fluid, uterus, breasts, extra blood, fluids, and fat stores.