By Dr Janice TUNG, Associate Consultant and Associate Professor Tan Thiam Chye, Visiting Consultant, Department of Obstetrics and Gynaecology, KK Women’s and Children’s Hospital

Pregnancy is an exciting time of change for your body. It’s also a period when it’s more important than ever to look after your health, and the health of your growing baby. In this guide, we will talk you through how plus-sized mothers can ensure a smooth and healthy pregnancy.

Related: Healthy Start For Your Pregnancy

Calculating Your BMI

Guidelines for Pregnancy Weight Gain

First up is determining what BMI, or Body Mass Index, you fall under. This is an important way to help determine the healthy amount of body weight gain you should aim for during your baby’s growth.

Simply take your pre-pregnancy weight in kilos, divided by your height squared (“squared” means to take your height multiplied by your height again).

If you have any questions, there are many BMI calculators online, or you can simply ask your doctor to help you calculate it. Here’s a handy table with recommended weight gains during pregnancy based on your BMI:

Related: BMI Calculator

How Being Plus-Sized Might Affect Your Pregnancy

Pregnant mother checking her weight during a doctor's appointment

Just as being overweight can have adverse effects on your everyday health, it can also negatively impact your pregnancy. Here are some common complications:

Diagnostic Difficulties

Added layers of fat around your belly can make it hard for the ultrasound scan to accurately “see” your baby and to spot any potential problems.

Gestational Diabetes

Your body requires more of the hormone insulin during pregnancy, which can increase the risk of becoming diabetic when your body is unable to produce enough insulin to control blood sugar levels. This type of diabetes usually clears up after pregnancy, but may persist in some women as standard diabetes. Women who are obese are more at risk of developing both standard diabetes and gestational diabetes. The condition can result in miscarriages or larger babies, which could lead to more difficult labour and deliveries.


Also known as pregnancy-induced high blood pressure, this condition is fairly common, affecting 10 percent of pregnancies. There would also be protein in the urine. In many cases, pre-eclampsia is difficult for mothers to pick up on, as there may not be any symptoms. It’s important to go for your routine antenatal check-ups, which will include a blood pressure check and urine test. But if you experience headaches, blurry vision, vomiting, sudden swelling of your hands, feet and face, or feel unwell, see your doctor immediately.

Labour Difficulties

You might be in for a longer pregnancy than planned. Women who are obese are more likely to find that the birth occurs after their planned due date. This is why severely overweight mothers may need an induced labour. They are also at a higher risk of needing an assisted vaginal delivery with forceps or vacuum cup, or a Caesarean section delivery. With regards to labour pain relief, obesity can affect the success of an epidural.

Related: How Being Plus-Sized Affects Your Pregnancy

How Being Plus-Sized Might Affect Your Baby

plus sized pregnancy and baby

It’s not just you who may experience adverse effects from being plus-sized; your baby may also be affected.


This is the official term for a baby born larger than normal, which can make for a complicated labour. For example, your doctor might find it more difficult to extract the baby during a vaginal or C-section birth.

Heart Defects, Diabetes and Obesity

Heart defects have been found to be more common in babies born to obese women, and they are more likely to develop diabetes and obesity later on in life.

Related: How Being Plus-Sized Affects Your Baby

Specialised Care for Plus-Sized Women

specialised care for plus sized women

Many plus-sized women undergo completely normal pregnancies, but to tip the odds in your favour, get proactive.

Early testing for gestational diabetes is a great start. Ask your doctor about it, and let them know if a close family member had gestational diabetes, which increases the risk of you getting it. Testing for gestational diabetes is usually done by an Oral Glucose Tolerance Test (OGTT). This requires you to drink a glucose solution after a night of fasting, followed by the drawing of blood samples before and after the solution. Should you be diagnosed with gestational diabetes, more regular check-ups and monitoring of your blood sugar levels will become routine, and you may be prescribed medication.

As mentioned, in some cases the ultrasound may have trouble penetrating excess belly fat. You may require more scans in order to try and detect problems. In some cases, certain birth defects, especially heart defects, may only be detected after birth.

Related: Gestational Diabetes: What You Need to Know

Healthy Habits if You’re Plus-Sized and Pregnant

healthy habits for plus sized and pregnant women

Many mothers find that the more they pre-plan, the more at ease they feel. So why not ask your doctor for any tips and advice before trying to get pregnant? They can answer any queries you have, offer a vitamin plan and perhaps recommend effective ways to shed kilos before conception.

Similarly, once you’re pregnant, regular visits are a great way for you and your doctor to monitor development and plan for any issues. To help this process, share any health conditions you think might be relevant: for example, whether you suffer from diabetes, high blood pressure or snoring, which may be a sign of sleep apnea.

You can also take control of your diet, which will give you peace of mind and put you in the driver’s seat of maintaining your and your baby’s health, every day. Don’t just embark on a crash diet — for one thing, your body will need nutrients such as folic acid, calcium, iron and more at this time. Instead, come up with a diet plan that’s suitable for pregnancy through consultation with a dietician.

Healthy eating is, of course, best paired with appropriate exercise. Again, don’t overdo it: aim for gentle but effective activities, which can be as simple as walking, swimming or yoga. Hitting 30 minutes of exercise a day is a good level, but if you find it hard to reach this point, just take it a little day by day. Start with a five-minute workout a day, and add five minutes each subsequent day. Just be sure to keep it at a manageable level — you don’t have to feel like you’re training for a marathon! A good rule of thumb is that if you’re not able to talk normally during your exercise, you should take it down a notch.

If you or your partner smokes, the best thing you can do is to quit. For smokers, ditching this unhealthy habit will lower the risk of miscarriage, stillbirth or an underdeveloped baby — you’ll also feel better and healthier yourself. Staying off cigarettes after delivery will also ensure a healthier environment for your newborn.

Related: 4 Habits to Manage Your Weight if You're Plus Sized

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Read these next:


  1. Tan, T., Tan, K., Tan, H., & Tee, J. C. (2008). The New Art and Science of Pregnancy and Childbirth.. New Jersey: World Scientific.

  2. Health Promotion Board. (2013). Healthy Start for your Pregnancy. Singapore: Health Promotion Board.