How Obesity Affects Pregnancy

Obesity during pregnancy can have very important consequences for the health of the mother and fetus. If you're overweight, you must start eating healthy.
How Obesity Affects Pregnancy
Saúl Sánchez Arias

Reviewed and approved by the nutritionist Saúl Sánchez Arias.

Written by Naí Botello

Last update: 17 March, 2023

A woman is considered overweight when she has excess body fat and her body mass index (BMI) is greater than 30. Her life and her baby’s could be in danger if she’s pregnant. That’s why it’s important to know how obesity affects pregnancy.

The consequences of obesity during pregnancy are alarming. For the mother, the threats include gestational diabetes and preeclampsia. For the baby, physical defects are possible. In addition, there’s an increased risk of dying in the womb.

If you’ve done tests that indicate that you’re overweight, we’ll give you some tips. They’ll help you prevent and treat this condition.

What is obesity?

To talk about how obesity affects pregnancy, first we need to define what it is. We also need to discuss the parameters to define it.

Obesity is considered to be a type of functional disease. However, it’s preventable. In it, excess amounts of fat build up in the body.

According to doctors’ parameters, a person is obese if his or her BMI is equal to or greater than 30 km/m2. For non-pregnant women, it can also be true if their abdomen is greater than or equal to 35 inches.

People with obesity are at risk of suffering from metabolic syndrome. Basically, it involves diseases such as diabetes, heart problems, skin problems, gastrointestinal discomfort, stroke and osteoarthritis. In extreme cases, it can also lead to cancer.

How Obesity Affects Pregnancy

How obesity affects pregnancy

If people suffering from obesity are at risk of developing one or more diseases, what happens to women who are pregnant and overweight? Below we’ll discuss some of the ways that obesity affects pregnancy.

For starters, women with obesity have more difficulty getting pregnant. This is because the excess fat in the body inhibits ovulation. This condition can be so radical that some people even experience failure with in vitro fertilization.

However, if you’re already pregnant, the direct consequences of obesity could be:

  • Prone to urinary tract infections during pregnancy and after childbirth. Also, it doesn’t matter whether the birth was vaginal or by cesarean section.
  • High blood pressure and preeclampsia. In addition, there could be proteins in the urine starting at week 22 of pregnancy.
  • Suffer a thrombosis. That is, blood clots form inside a blood vessel.
  • Gestational diabetes.
  • Pregnancy can be prolonged for longer than normal.
  • In many cases, you’ll need a cesarean section.
  • Miscarriage
  • In the most unfortunate cases, the child may die in the womb.

“For the mother, the threats of obesity during pregnancy include gestational diabetes and preeclampsia. For the baby, physical defects are possible.”

How does obesity of the mother affect the fetus?

As expected, the mother’s obesity also harms the fetus. The health complications that can affect it are:

  • Risk of developing heart disease
  • Risk of suffering from diabetes at a young age or in adulthood.
  • Possibility of having neural tube defects. This implies that the brain or spine don’t form correctly.
  • Physical malformations
  • Macrosomia. This is where a child has a weight, size and body fat index that’s higher than average children.
  • Children of overweight mothers tend to be obese as children.
  • Dystocia in the shoulder at the time of delivery. This is because they’re generally larger than normal.

How pregnant women with obesity can take care of themselves

If you’re pregnant and are already considerably overweight, you should know that the doctor treating your pregnancy will be responsible for checking your health periodically. In addition, you need to stick to the diet and exercise plan your doctor makes for you.

You’ll also have several tests to check for gestational diabetes. Likewise, you’ll have your ultrasound at the 22nd week instead of the normal 18th week.

This is because the amount of adipose tissue makes it hard to see on the ultrasound. Finally, you’ll have more than one fetal echocardiogram to rule out congenital problems.

As a final recommendation, if you want to get pregnant and struggle with obesity, make sure to take care of yourself.

Eating healthy and exercising regularly will benefit both you and your future baby. Thanks to these habits, you can avoid suffering medical complications.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Salaun H., Thariat J., Vignot M., Merrouche Y., et al., Obesity and cancer. Bull Cancer, 2017. 104 (1): 30-41.
  • Simjak P., Cinkajzlova A., Anderlova K., Parizek A., et al., The role of obesity and adipose tissue dysfunction in gestational diabetes mellitus. J Endocrinol, 2018.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.