Once they're pregnant, women have a lot of checkups to make sure they stay healthy. But a mom's health preconception is vitally important, too, and a growing cause for concern.
Increasingly, moms in the United States are starting their pregnancies already having heart risks like high blood pressure (hypertension), diabetes and obesity.
A new study finds that 60% -- even higher in some states -- of pregnant women have one or more of these complications of pregnancy.
"We were quite surprised that only 40% of women entered pregnancy with a normal weight without diabetes and without hypertension," said lead author Dr. Natalie Cameron, an internal medicine specialist and instructor at Northwestern University's Feinberg School of Medicine in Chicago.
"Even more surprising are the geographic differences we found," Cameron said, referring to lower cardiometabolic health in Midwestern and Southern states. At the low end, just 31% of moms-to-be had good heart health in Mississippi, compared to nearly 50% in Utah at the upper end.
While women in the West and Northeast fared better, they still had plenty of room for improvement: In the West, just over 42% had good heart health and in the Northeast, just under 44%.
The Northwestern University researchers used the U.S. Centers for Disease Control and Prevention Natality Database from 2016 to 2019, identifying pre-pregnancy heart health risk factors of more than 14 million women between the ages of 20 and 44. To have optimal heart health, the women needed to have a normal-range body mass index (BMI) and not have high blood pressure or diabetes. BMI is a measure of body fat based on height and weight.
The most common of those three heart health risk factors was being overweight or obese. Only about 42% of women ages 30 to 34 had good heart health, as did 37% of those ages 40 to 44.
Women were slightly healthier overall in 2016, with 43.5% per 100 births having good heart health, than in 2019, when just 40% had good heart health.
The risks can be significant. About 1 in 4 pregnancy-related deaths is caused by heart disease, according to the American Heart Association.
Their babies may be born early or at small gestational age. And the effects of having poor heart health during pregnancy can affect the children for years.
"Optimizing health prior to pregnancy is really important for the health of the pregnancy and also for the health of the baby," Cameron said.
The mothers, too, can experience the impact of having these risk factors years later.
"Entering pregnancy with poor cardiometabolic health increases your risk of adverse pregnancy outcomes, and adverse pregnancy outcomes are considered a risk-enhancing factor for cardiovascular disease later in life," Cameron said.
The reason for the geographical differences appears to be social determinants of health, including education, Medicaid enrollment, access to preventive care, ability to afford healthy foods and neighborhood characteristics, such as green space, the researchers noted.
"Women in this age group are generally not evaluated by preventive cardiologists and also are focusing on caring for their families and children," said Dr. Garima Sharma, a heart association volunteer expert who reviewed the study.
"They need to focus on their own health and cardiovascular disease risk factors," said Sharma, an assistant professor of medicine at Johns Hopkins School of Medicine in Baltimore. "These trends are concerning and addressing this in pre-pregnancy counseling and by internal medicine doctors is important."
Sharma called pregnancy "nature's stress test" because so many changes occur in a woman's cardiovascular system during these months. This includes increased blood circulation that can put an extra burden on a woman's heart.
Women can be proactive about their health by speaking to their doctors about cardiovascular risk factors prior to pregnancy, getting conditions under control, not smoking and maintaining a balanced diet and healthy weight, Sharma said.
"If cardiovascular health is suboptimal at baseline, it puts that mother at risk of immediate adverse outcomes," Sharma said. "But we are still learning about what subclinical changes occur in the heart and vascular system of these mothers postpartum that cause an increase in their risk."
The findings were published Feb. 14 in the journal Circulation.
For some women, pregnancy is what jump-starts regular health care visits, so they are not diagnosed with these heart risks until after a pregnancy begins.
The researchers called for changes in public health, asking not "what can women do," but what can society do to support mothers through public health policies that improve access to care and that invest in communities.
"So, increasing education about cardiometabolic health, increasing access to care, encouraging women to go to the doctor to optimize their health prior to pregnancy and just making prevention part of our culture in medicine and throughout the U.S.," Cameron said.
The U.S. National Heart, Lung, and Blood Institute has more on heart health in pregnancy.
SOURCES: Natalie A. Cameron, MD, internal medicine specialist and instructor, Northwestern University Feinberg School of Medicine, Chicago; Garima V. Sharma, MBBS, director, cardio-obstetrics and assistant professor, medicine, Johns Hopkins School of Medicine, Baltimore; Circulation, Feb. 14, 2022