Obesity during pregnancy increases the risk of complications for both the pregnant person and the child.

People with obesity may have an increased risk of developing various health conditions, including hypertension and diabetes.

Obesity can also be a significant health concern during pregnancy. It increases the risk of pregnancy and delivery complications for both the pregnant person and the child and can affect the child’s health into adulthood.

This article explores how obesity affects pregnancy and how to manage it to ensure a healthy pregnancy.

Black and white image of a pregnant person's body in a doctor's officeShare on Pinterest
SDI Productions/Getty Images

“Overweight” and “obesity” are terms that describe having a higher weight than experts consider healthy for a person’s height. Obesity also involves excessive body fat.

Body mass index (BMI) is a medical measurement that estimates body fat by dividing a person’s weight in kilograms by the square of their height in meters.

A BMI of 30 or higher falls within the range of obesity. Here are the BMI weight classifications for reference:

BMIWeight classification
under 18.5underweight
18.5–24.9normal weight
30.0–34.9obesity class 1
35.0–39.9obesity class 2
40 or higherobesity class 3

See BMI calculators and charts.

While many people with overweight or obesity have healthy pregnancies, obesity increases a person’s risk of developing serious health problems during pregnancy. Potential health concerns include:

Gestational diabetes

Gestational diabetes (GDM) is a type of diabetes that a person without prior diabetes can develop during pregnancy. Pregnant people with obesity have a three times greater risk of developing GDM than people without obesity.

In one 2016 study, pregnant people with GDM were more likely to have emergency cesarean deliveries than those without GDM.

Gestational hypertension

Gestational hypertension is high blood pressure that begins during the second half of pregnancy. A 2018 Iranian study found that gestational hypertension was 1.79 times more likely to occur in pregnant people with obesity than in those who had a BMI in the “normal” range.


Preeclampsia is a serious pregnancy-related high blood pressure disorder that can develop after 20 weeks of pregnancy or after giving birth. According to a 2022 research review, people with obesity have a three to four times greater risk of preeclampsia.

Obstructive sleep apnea

Obstructive sleep apnea (OSA) is a sleep disorder that causes repeated episodes of complete or partial collapse of the upper airway during sleep.

It can also cause fatigue and increase the risk of complications such as preeclampsia and high blood pressure. Pregnant people with obesity are at risk of OSA, and those with OSA are more likely to develop GDM.

Venous thromboembolism

Venous thromboembolism happens when blood clots form in a vein. Obesity is a major contributing factor to venous thromboembolism during pregnancy.

In addition to potentially contributing to complications during pregnancy and labor, obesity can affect the health of the fetus. It may also affect the health of the child into adulthood.

Fetal and neonatal complications

Babies born to people with overweight or obesity have a higher risk of congenital anomalies such as:

These newborn babies are also at risk of developing obesity and metabolic disorders, such as high cholesterol and diabetes, in childhood.

Additionally, a developing baby may be larger than expected for their gestational age. Doctors refer to this as macrosomia. It increases the risk of traumatic injuries and unfavorable delivery outcomes for both the pregnant person and the baby.

Labor and delivery complications

Pelvic pain and labor complications are more common in pregnant people with obesity, and pain relief during labor is more challenging.

Prepregnancy obesity increases the risk of cesarean delivery after induced labor in pregnant people with a BMI of 25–34.9. Pregnant people with obesity or severe obesity also have twice the risk of stillbirth, according to a 2023 Swedish study.

Overweight and obesity increase the risk of:

Despite the risks, a pregnant person with obesity can have a healthy pregnancy. Regular prenatal care is necessary to avoid or monitor complications.

The American College of Obstetricians and Gynecologists and the Institute of Medicine recommend that pregnant people with a BMI of 30 or higher gain 5–9 kilograms (kg), or 11–20 pounds (lb), during pregnancy, with an average weight gain of 0.23 kg (0.4 lb) per week in their second and third trimesters.

Some methods a person’s care team may use to manage the pregnancy include:

  • recommendations on weight gain during pregnancy
  • nutritional supplements
  • vaccinations against illnesses such as COVID-19 and influenza
  • ultrasound scans
  • monitoring for complications such as preeclampsia
  • glucose tolerance testing for GDM
  • anesthetic assessment for cesarean section

A doctor may recommend obtaining baseline labs such as a comprehensive metabolic panel, lactate dehydrogenase, and complete blood count, as well as urine tests such as urine protein creatinine ratios, for all pregnant people with obesity.

Doctors may also recommend other tests, such as:

  • vitamin deficiency screening
  • thyroid screening
  • OSA screening
  • ultrasound for congenital anomalies

The doctor may refer the pregnant person to a specialist, such as an endocrinologist or dietitian, when necessary.

Pregnant people with obesity may have challenges with pain relief and prolonged labor. Advance planning for pain relief options may be necessary.

Early epidural placement may be necessary for those proceeding with a vaginal birth.

High body fat can also make it more challenging to monitor the fetal heart rate during labor. This increases the likelihood that a person will have a cesarean delivery.

If the healthcare team opts for a cesarean delivery, they may recommend steps to reduce the risk of complications such as blood clots. Other common post-cesarean complications associated with obesity include:

  • wound infections
  • wound opening
  • infections

Doctors may provide higher doses of broad-spectrum antibiotics to people with obesity who are undergoing cesarean delivery.

There are several steps a pregnant person with obesity may take to increase their chance of a healthy pregnancy, including:

  • eating a variety of fruits, vegetables, whole grain foods, low fat milk products, oily fish, and lean meats
  • drinking 6–8 glasses of water daily
  • exercising for at least 30 minutes on most days of the week
  • making efforts to limit weight gain during pregnancy
  • limiting consumption of foods that are highly processed or high in added sugar, salt, or saturated fat

Learn more about foods to eat and avoid during pregnancy.

Those with a BMI of 30 or higher should take a daily dose of 5 milligrams of folic acid, ideally from 1 month before they conceive until their 13th week of pregnancy.

People with obesity who plan to get pregnant may wish to visit their doctor or midwife to discuss any challenges their weight may present and whether weight loss is advisable before attempting to conceive.

If necessary, the doctor or midwife may refer the person to a registered dietitian who can help them plan a healthy diet.

Obesity is a common condition that can increase the risk of pregnancy complications such as gestational diabetes, preeclampsia, and stillbirth.

However, many people with obesity have healthy pregnancies with careful management from their health team.

Regular prenatal care and management of weight gain during pregnancy can help reduce the risk of complications. It is advisable for people to eat a balanced diet and exercise regularly to maintain a healthy pregnancy.

Pregnant people with obesity may have additional tests and monitoring during pregnancy and labor.