Picture

Northwestern Medicine
​Breakthroughs for Physicians

​​
  • Home
  • Specialties
    • Cardiovascular >
      • Research
      • Clinical Breakthroughs
      • News
    • Endocrinology >
      • Clinical Breakthroughs In Endocrinology
      • Research In Endocrinology
      • News
    • ENT (Otolaryngology) >
      • Clinical Breakthroughs
      • Research
      • News
    • Gastroenterology >
      • Clinical Breakthroughs
      • Research
      • News
    • Geriatrics >
      • Clinical Breakthroughs
      • Research
      • News
    • Neurosciences >
      • Rare and Complex Brain Tumors
      • Research
      • COVID-19 and Neurosciences
      • News
      • Clinical Breakthroughs
    • OB-GYN >
      • Clinical Breakthroughs
      • Research
      • News
    • Oncology >
      • Clinical Breakthroughs
      • Research
      • News
    • Ophthalmology >
      • Clinical Breakthroughs
      • Research
      • News
    • Organ Transplant >
      • Clinical Breakthroughs
      • Research
      • News
    • Orthopaedics >
      • Clinical Breakthroughs
      • Research
      • News
    • Psychiatry >
      • Clinical Breakthroughs
      • Research
      • News
    • Pulmonary >
      • Clinical Breakthroughs
      • Research
      • News
    • Rehabilitation >
      • Clinical Breakthroughs
      • News
    • Rheumatology >
      • Clinical Breakthroughs
      • Research
      • News
    • Urology >
      • Clinical Breakthroughs
      • Research
      • News
  • CME
  • REFERRALS
    • Refer to NM Cardiovascular
    • Refer to NM Neurosciences
    • Refer to Other Specialties

< BACK TO RESEARCH IN CARDIOVASCULAR

October 2023

CARDIOVASCULAR

PRE-PREGNANCY OBESITY PREDICTS FUTURE HEART HEALTH

Featuring: Sadiya Khan, ’09 MD, ’14 MSc, ’10, ’12 GME

‘Pregnancy reveals the risk that is already there’
​

Pregnancy complications such as preeclampsia and gestational diabetes have recently been associated with a higher risk of developing heart disease later in life. But a new Northwestern Medicine study published in Circulation Research has found obesity before or during pregnancy is the actual root cause of future cardiovascular disease.

Prior to this study, scientists were unsure which factor — obesity or pregnancy complications — played a larger role in cardiovascular disease risk years after pregnancy. This large, multi-center and diverse study is the first to disentangle that question, ultimately determining that pre-pregnancy obesity is the true driver of both poor pregnancy outcomes and future cardiovascular disease risk. It is one of the only studies to follow its participants — about half of whom were overweight or had obesity — from the beginning of their first pregnancy through several years postpartum.

“We demonstrate, for the first time, that adverse pregnancy outcomes are primarily indicators — and not the root cause — of future heart health,” said corresponding author Sadiya Khan, ’09 MD, ’14 MSc, ’10, ’12 GME, the Magerstadt Professor of Cardiovascular Epidemiology in the Departments of Medicine and Preventive Medicine, and a Northwestern Medicine physician. “This means that pregnancy just reveals the risk for heart disease that is already there.”

The findings were published Oct. 10 in the journal Circulation Research.
​
​The study used data from the nuMoM2b Heart Health Study to prospectively follow 4,216 first-time pregnant individuals from the early stages of their pregnancy to an average of 3.7 years postpartum. At the early-pregnancy first study visit, the average maternal age was 27 years old, and 53 percent had a normal body mass index (BMI), 25 percent were overweight and 22 percent had obesity. Compared to those with a normal BMI in early pregnancy, individuals with overweight or obese BMI had a higher risk of developing hypertensive disorders of pregnancy.

‘Pregnancy is a natural stress test for the heart’

In the study, the scientists wanted to better understand the associations among maternal obesity, hypertensive disorders of pregnancy and other adverse pregnancy outcomes and cardiovascular health several years after delivery.

“Our hypothesis was that it may be that the pregnancy complications are unmasking these things since, as we know, pregnancy is a natural stress test for the heart,” Khan said. “These findings are important because if pre-pregnancy obesity is the culprit or cause of risk, we should be targeting this with interventions.”

“We don’t want to just wait until people have these cardiovascular events; we want to stop them from happening,” Khan said.

Obesity intervention before pregnancy is key

A major throughline of Khan’s research is the idea of the “Zero trimester,” or pre-pregnancy health. By improving health during this critical time in an individual’s life, they can improve outcomes for not only their pregnancy and baby but for their personal long-term health, Khan said.

However, it can be difficult to target people before becoming pregnant, Khan said. So, early in the pregnancy may be an opportune time to counsel on heart-healthy habits like diet and exercise when people are more likely to be interacting with clinicians during prenatal visits.

“We definitely do not want to recommend weight loss during pregnancy but do want to recommend counseling and monitoring for appropriate gestational weight gain,” Khan said. “It is one of the few times in life that you are seeing the doctor frequently while you’re healthy.”

Pregnant individuals can safely limit their weight gain throughout pregnancy by eating healthy and exercising moderately or even vigorously, studies have shown.

​More about the study

Pregnant individuals in the study were seen at eight clinical centers across the U.S., including Northwestern University. Individuals were 18 years or older and did not have any history of pre-pregnancy hypertension or diabetes.

Approximately 15 percent of all participants experienced a complication related to high blood pressure; 11 percent had a baby with a low birthweight; 8 percent had a preterm birth; and 4 percent had gestational diabetes. In the years following pregnancy, those with complications related to high blood pressure were 97 percent more likely to have high blood pressure, and 31 percent were more likely to have high cholesterol.

For some complications, the investigators found body weight did not factor into risks. For example, people who were overweight or had obesity did not have increased risks for having a preterm birth or a baby with a low birthweight.

​However, among all participants, those experiencing preterm births had increased risks for having high blood pressure, high blood sugar or high cholesterol after pregnancy. Having a baby born with a low birthweight wasn’t found to increase risks.
​
Funding for the study was provided by National Heart, Lung, and Blood Institute grant R01 HL161514. The Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Center for Advancing Translational Sciences, Office of Research on Women’s Health and the Office of Disease Prevention provided additional support.

This article was originally published in the Feinberg School of Medicine News Center on October 12, 2023. 
Sadiya Khan, ’09 MD, ’14 MSc, ’10, ’12 GME headshot
Sadiya Khan, ’09 MD, ’14 MSc, ’10, ’12 GME, the Magerstadt Professor of Cardiovascular Epidemiology in the Departments of Medicine and Preventive Medicine, and a Northwestern Medicine physician, was senior author of the study published in Circulation Research.

Refer a Patient

Northwestern Medicine welcomes the opportunity to collaborate with you in caring for your patients. ​
Refer to Us
Find a Cardiovascular Physician

You May Also Like

Headshot of Dr. Faraz Ahmad
​

January 2022

CARDIOVASCULAR
Using Machine Learning to Identify Patients with Advanced Heart Failure
Physician looking at screens

January 2022

CARDIOVASCULAR
Artificial Intelligence and the Development of Cardiovascular Health Care Solutions
Headshot of Dr. Ramsey Wehbe

December 2021

CARDIOVASCULAR
Harnessing Artificial Intelligence to Improve Cardiovascular Care

Northwestern Medicine Breakthroughs for Physicians

About Us     Terms of Use     Privacy Policy     How to Vote for U.S. News & World Report Best Hospitals
© 2025 Northwestern Medicine® and Northwestern Memorial HealthCare. 
Northwestern Medicine® is a trademark of Northwestern Memorial HealthCare, used by Northwestern University
Connect with us
[email protected]
International physicians, contact [email protected]
  • Home
  • Specialties
    • Cardiovascular >
      • Research
      • Clinical Breakthroughs
      • News
    • Endocrinology >
      • Clinical Breakthroughs In Endocrinology
      • Research In Endocrinology
      • News
    • ENT (Otolaryngology) >
      • Clinical Breakthroughs
      • Research
      • News
    • Gastroenterology >
      • Clinical Breakthroughs
      • Research
      • News
    • Geriatrics >
      • Clinical Breakthroughs
      • Research
      • News
    • Neurosciences >
      • Rare and Complex Brain Tumors
      • Research
      • COVID-19 and Neurosciences
      • News
      • Clinical Breakthroughs
    • OB-GYN >
      • Clinical Breakthroughs
      • Research
      • News
    • Oncology >
      • Clinical Breakthroughs
      • Research
      • News
    • Ophthalmology >
      • Clinical Breakthroughs
      • Research
      • News
    • Organ Transplant >
      • Clinical Breakthroughs
      • Research
      • News
    • Orthopaedics >
      • Clinical Breakthroughs
      • Research
      • News
    • Psychiatry >
      • Clinical Breakthroughs
      • Research
      • News
    • Pulmonary >
      • Clinical Breakthroughs
      • Research
      • News
    • Rehabilitation >
      • Clinical Breakthroughs
      • News
    • Rheumatology >
      • Clinical Breakthroughs
      • Research
      • News
    • Urology >
      • Clinical Breakthroughs
      • Research
      • News
  • CME
  • REFERRALS
    • Refer to NM Cardiovascular
    • Refer to NM Neurosciences
    • Refer to Other Specialties