This sheet is about obesity in pregnancy and while breastfeeding. This information is based on available published literature. It should not take the place of medical care and advice from your healthcare provider.
What is obesity?
Obesity is a condition that is associated with too much body fat. One measure of obesity is body-mass index (BMI) which is an estimate of body fat based on height and weight. A person is said to be obese when their BMI is 30 or higher and overweight when their BMI is between 25 and 29.9. The Centers for Disease Control and Prevention (CDC) has a tool to find your BMI: https://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/english_bmi_calculator/bmi_calculator.html
What about weight gain during pregnancy?
Weight gain during pregnancy is expected. The suggested amount of weight gain during pregnancy can be different based on your weight/BMI before pregnancy and the number of fetuses that you are carrying. In general, a total weight gain of 15–25 pounds for people who are overweight and 11–20 pounds for people who are obese is recommended during pregnancy. However, it is important to work closely with your healthcare providers to determine how much weight you should gain during pregnancy.
Should I try to lose weight while pregnant?
Weight loss is usually not recommended during pregnancy. If you are already pregnant and overweight or obese, limiting your weight gain might be recommended. Talk with your healthcare provider before trying to lose weight during pregnancy. They can go over your recommended weight gain, nutrition, and exercise.
I am obese. Can it make it harder for me to get pregnant?
Studies have shown that it can take longer for people who are obese to get pregnant. Also, they may have a lower chance of getting pregnant.
Can obesity increase the chance of miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. Obesity has been associated with an increased chance of miscarriage.
Can obesity increase the chance of birth defects?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Obesity during pregnancy has been associated with a higher chance for certain birth defects, including heart defects or defects of the brain, spine, or spinal cord (neural tube defects [NTDs]). While the overall increased chance for birth defects is expected to be small, risks may be higher depending on a person’s level of obesity.
Can obesity increase the chance of other pregnancy-related problems?
Obesity can increase the chance for gestational diabetes, high blood pressure, bleeding after pregnancy (postpartum hemorrhage), preterm delivery (birth before week 37) and stillbirth. There are also reports of preeclampsia (high blood pressure and problems with organs, such as the kidneys) that can lead to seizures (called eclampsia). Obesity has also been associated with a greater chance for a C-section delivery. Babies of people who are pregnant and obese have an increased chance for large body size (macrosomia, greater than 8 pounds, 13 ounces [4000 grams]), which can lead to other complications with delivery and/or the child. Some of the complications for the child could include low blood sugar, an increased chance of childhood obesity, and heart conditions.
For more information on gestational diabetes, see the MotherToBaby fact sheet https://mothertobaby.org/fact-sheets/diabetes-pregnancy/.
Can obesity in pregnancy affect future behavior or learning for the child?
Some studies suggest an increased chance of learning difficulties, attention deficit/hyperactivity disorder, or autism when a person is obese during pregnancy. However, there are many factors that can affect behavior and learning, so it is unlikely that only one factor would be involved.
What screenings or tests are available to see if my pregnancy has birth defects or other issues?
Prenatal ultrasounds can be used to screen for some birth defects, such as heart defects and NTDs. Ultrasound can also be used to monitor the growth of the pregnancy. However, obesity can make it harder for birth defects to be detected by ultrasound. Talk with your healthcare provider about any prenatal screenings or testing that are available to you. There are no tests available during pregnancy that can tell how much effect there could be on future behavior or learning.
Breastfeeding and obesity:
People who are obese can successfully breastfeed. However, there is some information to suggest that people who are obese are less likely to start and keep breastfeeding than people who are not obese. If you have questions, concerns, or issues with breastfeeding, talk with your healthcare provider, your baby’s pediatrician, and/or a lactation consultant to get the support you need. Be sure to talk to your healthcare provider about all your breastfeeding questions.
If a male has obesity, can it make it harder to get a partner pregnant or increase the chance of birth defects?
Obesity in males can lower fertility (ability to get a partner pregnant). In general, exposures that fathers or sperm donors have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
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OTIS/MotherToBaby encourages inclusive and person-centered language. While our name still contains a reference to mothers, we are updating our resources with more inclusive terms. Use of the term mother or maternal refers to a person who is pregnant. Use of the term father or paternal refers to a person who contributes sperm.
