7 Complications of Excessive Weight Gain During Pregnancy

Written by Dr Sylvia Kama-Kieghe on Tue, 01 August 2023 — Fact checked by Dr. Kirilyuk Inna Anatolyivna

Key Highlights

  • Instead of eating for two, focus on the quality and variety of foods you eat when pregnant. 
  • Try to be at a healthy weight before you get pregnant. This will help you get back to your pre-pregnancy weight post delivery. 
  • Excess weight gain during pregnancy can lead to multiple complications such as gestational diabetes, pre-term delivery, still birth, and increased caesarian delivery. 

Contrary to some beliefs, adding too much weight when pregnant is not a good idea.Many women believe they need to support their growing baby in many ways when pregnant.

While that's true, it doesn't mean you have to increase your weight excessively to do so.

Thus, you can "eat for two" and not depend on becoming too overweight simply because you are pregnant.

What's the best Pregnancy Weight?

By the time most babies are born, they weigh between 3-4 kg.

So, the popular concept of “eating for two”( i.e. double quantities) doesn't apply as the second person only requires a small amount of nutrition which your body can provide without too many extras!

Instead of increasing your appetite, why not expand the quality and variety of food you eat?

This will ensure your baby is getting the right supplements to develop properly.

Here are some facts to be aware of regarding pregnancy weight.

Studies Suggest overweight women

  • Try to be at a healthy weight before you get pregnant. This means your BMI (body mass index) is between 18 and 24. Any higher, and you may have trouble ovulating and falling pregnant. Or if you do fall pregnant, you may be more at risk of miscarrying the pregnancy.
  • We recommend you not gain more than 8-10 kg while pregnant. Exact weight gain can vary from one woman to the next. This extra weight includes that of your baby, placenta, and womb, which grows while you are pregnant. In addition, you need a little extra fat and increased fluid and blood volume in your body to support you and your baby while pregnant.

Not only does this prevent complications, but it is hopefully easier for you to return to pre-pregnancy weight after you've had the baby.

At that time, your body needs to be as fit as possible to cope with the new life demands of a growing baby.

Also, suppose you've had different treatments during labour, like assisted birth, C-section, infections, episiotomy, etc.

In that case, you will recover quicker and better if your BMI is not too high.

7 Pregnancy Complications if excessively overweight

Apart from these mentioned above, here are seven complications that an overweight woman may face during pregnancy:

Gestational Diabetes

This is a condition where abnormally high blood sugar develops when pregnant (gestation). Just like developing Diabetes outside of pregnancy, gestational Diabetes doesn't only affect sugar metabolism. 

There are also problems with cholesterol and potential damage to several organs. Apart from the health risks to the mum, women with gestational Diabetes may also have bigger-sized babies (a condition known as Macrosomia).

An immediate problem this brings could be difficult vaginal delivery. For example, the child struggles to emerge from the birth canal, and after their head appears, the shoulders may become stuck in the birth canal. This is known as shoulder dystocia and is an emergency requiring urgent treatment.

Gestational Hypertension/Pre-eclampsia

Being overweight is associated with increased effort and strain on the heart and blood vessels. This similarly translates to pregnancy, where abnormally high blood pressure can rapidly cause life-threatening emergencies. 

Besides the effect on you, high blood pressure in pregnancy (gestational hypertension/pre-eclampsia) can lead to impaired growth and development of your baby.

Preterm Delivery

 This happens when you deliver your baby before the expected term (37-40 weeks of pregnancy). This may present serious problems to the baby, whose organs are not yet mature before they are born. Studies suggest that overweight women are at a higher risk of prematurely delivery.


 A stillbirth is when a baby is born dead after 24 completed weeks of pregnancy. We don't always know why it happens. Still, most often, conditions that complicate obesity, like Diabetes or hypertension, can lead to a stillbirth.

Birth Trauma

Overweight women having vaginal or caesarean section birth are at a greater risk of experiencing birth trauma. During a difficult vaginal birth, an overweight lady may require a cut/ episiotomy to allow delivery (particularly if her baby is large). 

Surgical delivery may also create complications with anaesthetic drugs or wounds that do not heal properly after birth.

Caesarean Delivery

Obese mums-to-be are more likely to have a surgical delivery (planned or emergency). 

Firstly, they may spend a long time in labour, become exhausted and struggle to deliver vaginally. Secondly, if the baby is large, the risk of getting stuck in the birth canal and the distress to the baby makes an emergency caesarean section inevitable.

Postpartum Complications

These are problems that happen immediately after birth and in the 6 weeks following. Examples include abnormal (heavy) vaginal bleeding or womb infections. These may occur for various reasons but could be more challenging to manage if you are overweight. 

Another significant postpartum problem (which can also happen at any time during the pregnancy) is developing blood clots. Blood clots are more likely to occur in pregnant and overweight women. When you are both overweight and pregnant, the risk is even greater.

 If you have a C-section, your limited mobility following surgery may also contribute to increased risk. The blood clots may affect the lungs directly (pulmonary embolism, PE). Or they can begin elsewhere in the body, like the arms or legs (deep vein thrombosis, DVT), before travelling to the lungs (PE), where they can quickly become fatal.

These are some problems women with excess weight during pregnancy may develop.

Tips to keep a healthy weight when planning to get pregnant (and while pregnant)

Keep your diet low

  • Base your meals around starchy food, especially wholegrain, in moderate amounts (for example, bread, rice, pasta, potatoes).
  • Eat plenty of fibre-rich foods (for example, fruit, vegetables, oats, beans, peas, and lentils).
  • Eat at least five portions of different fruits and vegetables each day.
  • Keep your diet low in saturated fat.
  • Only eat small portions of fried food, drinks and candy with added sugar (for example, cakes and fizzy drinks) and other foods high in fat and sugar. From some of the healthy foods you eat, your body can process and store healthy fats. Therefore, you do not need to add more to your diet.
  • Avoid skipping meals - especially breakfast.
  • Be intentional about the portion sizes of meals and snacks and how often you eat. Remember, they can quickly add up, so small amounts frequently should be your goal.

What's next?

Have you experienced any complications related to being overweight while pregnant? We'd love to hear from you in the comments section.

In addition, please speak to your health provider if you have any concerns about this topic.


Dr Sylvia Kama-Kieghe

Dr Sylvia Kama-Kieghe is a UK-based General Practitioner with a special interest in Women's Health and founder of Askawayhealth. She's also a tutor and medical student examiner. She is a Fellow of the Royal College of General Practitioners (FRCGP), Fellow of the Royal Society of Public Health (FRSPH), Fellow of the Royal Society of Medicine (FRSM), and holds a Diploma of the Faculty of Sexual and Reproductive Healthcare (DFSRH).

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