Gestational diabetes was significantly associated with an increased cardiometabolic risk within the first few years postpartum, according to data from more than 1 million women in the US.

“Pregnancy is the earliest cardiometabolic stress test most women will ever take, and we have been reading only one line of the result,” said lead author Lili (Larry) Liu, PhD, a postdoctoral fellow in the Department of Epidemiology and Population Health at Stanford University, Stanford, California.

“Gestational diabetes affects about 1 in 7 pregnancies worldwide and roughly 300,000 women each year in the United States, yet fewer than half return for the postpartum glucose test that guidelines recommend,” said Liu.

Although previous research has established an increased risk for cardiometabolic disease, data on the timing and incidence of cardiovascular-kidney-metabolic disorders after gestational diabetes have been limited, he added.

“The postpartum visit after gestational diabetes should be a cardiometabolic visit, not just a glucose visit,” he emphasized.

Commercial Database Analysis of Over 1 Million Women

In a study published in Obstetrics & Gynecology, Liu and colleagues reviewed data from April 2007 to October 2023 from the Merative MarketScan commercial database. The study included 1,153,998 women aged 12-55 years with commercial insurance, a single delivery, and no history of cardiovascular, kidney, or metabolic disorders. The mean age was 28 years and 8.2% had gestational diabetes. Participants were followed for a median of 2.4 years after delivery.

Gestational diabetes and subsequent conditions were identified using diagnosis codes requiring at least one inpatient claim or two outpatient claims. Primary outcomes included incident postpartum obesity, hypertension, hyperlipidemia, prediabetes, type 2 diabetes (T2D), metabolic syndrome, chronic kidney disease, and cardiovascular disease.

Overall, gestational diabetes was associated with a tenfold increased risk for T2D (adjusted hazard ratio [aHR], 10.02) and a fivefold increased risk for prediabetes (aHR, 5.32). Individuals with gestational diabetes also had greater risks for metabolic syndrome (aHR, 2.72), hyperlipidemia (aHR, 2.00), hypertension (aHR, 1.76), and obesity (aHR, 1.75) than those without gestational diabetes.

The risk for composite cardiovascular disease was also increased among individuals with gestational diabetes (aHR, 1.28), whereas the risk for chronic kidney disease was not (aHR, 0.96).

Individuals with gestational diabetes also had higher crude incidence rates per 1000 person-years of T2D (9.9 vs 1.0), prediabetes (12.9 vs 2.5), hypertension (13.9 vs 8.1), hyperlipidemia (19.9 vs 10.1), and obesity (26.3 vs 15.2).

“The tenfold risk of T2D was expected; reproducing it confirmed that the data behaved as they should,” Liu said. What was less expected, he added, was how quickly other cardiometabolic conditions emerged among women with no recorded hypertension, hyperlipidemia, or obesity before delivery.

The excess risk also persisted over time, with the risk for T2D diabetes remaining more than sixfold higher at 5-10 years postpartum.

“Gestational diabetes is not a condition that ends at delivery,” Liu said. “It identifies a woman whose cardiometabolic trajectory has already diverged.”

Expanding Postpartum Assessments

The study provided new information about the timing of postpartum cardiometabolic outcomes, Liu said.

“Blood pressure, lipids, and weight are not a problem for the next decade; they are already appearing in the same window when clinicians screen for glucose postpartum,” he said. The postpartum visit should therefore include assessment of blood pressure, lipids, and weight in addition to glucose, he added.

“The American College of Obstetricians and Gynecologists’ fourth trimester framework asks us to treat the months after birth as continuous care. Our findings specify what that care should include,” Liu said.

Although the study demonstrated the timing of cardiometabolic risk, further research is needed to determine how best to reduce it. Longer follow-up with measured laboratory values is particularly important because cardiovascular disease unfolds over decades, whereas the current study followed participants for only a few years, Liu said.

The use of claims data was another limitation, given that diagnosis codes did not provide blood pressure or A1c measurements.

Trials are also needed to evaluate nonpharmacologic strategies for cardiometabolic prevention after gestational diabetes, including care navigation, self-monitoring at home, and coaching that extends beyond the 6-week postpartum visit, Liu said.

“An open question is whether a single pathway covering glucose, blood pressure, lipids, and weight changes trajectories, and whether the gains hold beyond a year,” he noted.

Structural barriers to postpartum care also remain.

“The handoff from obstetrics to primary care is where these women are lost,” Liu said. He noted particular challenges among those with Medicaid or without insurance coverage, as well as groups such as Asian American women, among whom gestational diabetes prevalence is high.

“Unless we build and test that bridge where it is weakest, we will have refined risk prediction only for the women already best served,” he added.

Challenges in Follow-Up Care

Although the association between gestational diabetes and subsequent T2D is well known, the study provided large-scale data on other components of cardiovascular-kidney-metabolic syndrome, said Diana Isaacs, PharmD, an endocrine clinical pharmacy specialist at the Cleveland Clinic Endocrinology & Metabolism Institute, Cleveland.

Isaacs, who was not involved in the study, said the findings were not unexpected.

“However, I think we are often so focused on the dysglycemia and not appreciating the impact of gestational diabetes on the full cardiometabolic system and the added lifetime risk of cardiovascular events,” she said.

For clinicians, the findings highlight the need for better postpartum care transitions so cardiovascular-kidney-metabolic risk factors can be closely monitored, she said. Although individuals with gestational diabetes generally receive close follow-up during pregnancy, many are lost to follow-up after delivery, and rates of recommended postpartum diabetes testing remain low.

Successful strategies are needed to improve postpartum follow-up and manage these risk factors, Isaacs said. Some high-risk women become pregnant again without realizing they have developed T2D until A1c testing during the first trimester of their next pregnancy, she noted.

Developing care models that accommodate the demands faced by busy mothers with newborns remains a challenge, she added.

Prospective studies following patients for decades after pregnancy remain limited because of the financial, logistical, and methodological challenges involved, said Amy Valent, DO, MCR, associate professor and medical co-director of the diabetes and pregnancy program at Oregon Health and Science University, Portland, Oregon.

Data on the long-term effects of gestational diabetes on cardiometabolic outcomes beyond T2D also remain limited, said Valent, who was not involved in the study.

“Although MarketScan data are not without limitations, their size and breadth make it possible to evaluate these important associations in large populations without the expense and complexity of a long-term prospective trial,” she said.

The findings reinforced that gestational diabetes can serve as early warning sign of future cardiometabolic disease, Valent said. Although the long-term risks associated with gestational diabetes have been recognized for decades, developing effective strategies for ongoing surveillance, counseling, and timely intervention remains a critical opportunity to improve long-term health outcomes, she added.

Valent pointed to the National Diabetes Prevention Program, which included participants with a history of gestational diabetes and showed reductions in progression to T2D with a 12-month life-coaching program or metformin. More studies are needed to determine whether similar approaches can reduce cardiovascular and kidney risks after gestational diabetes, she said.

Disclosure information for the authors is available in the original study publication. Isaacs and Valent reported having no financial conflicts of interest.