Obesity in Pregnancy: How Being Overweight Affects You and Your Baby

Obesity In Pregnancy and Its Complications | Miami Center of Excellence

Overweight pregnant woman on a scale.

If you’re starting out your pregnancy overweight or obese, you are far from the only one. Did you know that 53% of American women start their pregnancies overweight? And more than half of those women gain more than the recommended amount during their pregnancy. Obesity in pregnancy can bring on a multitude of unwanted complications for you and your little one. Here, we’ll discuss the various complications of obesity in pregnancy, and what you can do to maintain (or even lose) weight in a healthy way while pregnant.


What Is Considered Obese?

While the science of obesity may be changing, the current guidelines of obesity consist of having a BMI (body mass index) of 30% or higher. (You can find your BMI using by an online calculator.) Within the category of obesity, there are three levels that have increased health risks with each increasing BMI:

  • Lowest risk is a BMI of 30–34.9.
  • Medium risk is a BMI of 35.0–39.9.
  • Highest risk is a BMI of 40 or greater.


What Are The Complications for Obesity in Pregnancy?

When discussing the complications of being obese while pregnant, it’s important to look at the effects for both you as the mother, and the baby. While there is a chance you can go through your whole pregnancy with no issues, being obese will put at a much higher risk for the following:

  • Gestational Diabetes:  Diabetes that is first diagnosed during pregnancy. Women who have gestational diabetes are considered higher-risk for having diabetes in the future. Their children are also at a greater risk of developing diabetes.
  • Cesarean Delivery: While there are many factors that can lead to having a c-section, obese women and women with gestational diabetes are more likely to need one, either through a planned surgery or by emergency.
  • Preeclampsia: The higher your BMI, the greater the likelihood of having high blood pressure that occurs during or after pregnancy. It can lead to a condition called Eclampsia. This can cause seizures, kidney and liver failure, and in rare cases, stroke. Severe cases need emergency treatment to avoid these complications and your baby may need to be delivered early.
  • Sleep Apnea: A condition in which a person stops breathing for short periods of time during sleep. Sleep apnea is more prevalent in those that are obese. While pregnant, sleep apnea can cause fatigue, high blood pressure, preeclampsia, eclampsia, and heart and lung disorders.


Complications For The Baby

If the complications for you aren’t enough to worry about, obesity can also result in a wealth of problems for your baby.

  • Pregnancy Loss: Obese women have an increased risk of miscarriage compared to women with a healthy BMI.
  • Birth Defects: Babies born to obese women have an increased risk of having birth defects, such as heart defects and neural tube defects.
  • Diagnostic Testing Issues: Having too much body fat can make it difficult to see certain problems with the baby’s anatomy. Checking the baby’s heart rate during labor also may be more difficult if you are obese.
  • Macrosomia: Or rather having a larger-than-normal baby. This can increase the risk of injury during delivery for both the baby and the mother. Many babies with macrosomia are delivered via cesarean and have a greater chance of being obese later in life.
  • Preterm Deliveries: Babies that are born before the 37th week of pregnancy. This could happen spontaneously, or be medically induced by your medical professional. Preterm babies are not as developed as babies born after 39 weeks and have an increased risk of short-term and long-term health issues.
  • Stillbirth: The higher your BMI during pregnancy, the greater the risk of having a stillbirth.


Can I Lose Weight Safely While Pregnant?

If you are considered obese and thinking about becoming pregnant, losing even the smallest amount of weight can help your fertility as well as your overall health. Even a drop of 5-7% body weight (roughly 10-20lbs) can improve your chances of getting pregnant and having a healthier pregnancy.

What if you have a surprise pregnancy, or you conceived earlier than you expected? It’s still possible to lose weight in a healthy way while pregnant. Your obstetrician may refer you to a nutritionist to get you on a food plan that is good for you and the baby. A few things to keep in mind are:

  • Buy foods that are whole in fiber and protein. These foods are not only calorie-efficient, but they make you feel fuller longer. (As a bonus, a fiber-rich diet will also help with the inevitable pregnancy constipation.)
  • If you are considered obese, it is considered safe to reduce your maintenance calories (the number of calories you need to take in to maintain your current weight) by around 350 per day. You can manage your caloric intake by using any one of the numerous calorie-counting apps on the market. These apps will also help you determine what your maintenance calories are.
  • Aim to be moderately active during your pregnancy. 60 minutes of vigorous exercise 3 times per week, or 30 minutes of exercise most days. If you can’t do it all at once, breaking it up throughout the day is also good. As long as you’re moving!

Note: Before you start ANY diet and exercise program, discuss what is safe and healthy with your obstetrician.


Taking an active role in having a healthy pregnancy is the best decision you can make for yourself and your baby. At Miami Center of Excellence, we’ll guide you through this important, but delicate topic with the care and sensitivity you deserve.


If you’re pregnant or trying to become pregnant and worried about how your obesity will affect you and your baby, schedule an appointment with our office by phone at (305) 515-5425, or online.