Gestational Diabetes Rates Climb Among All Racial, Ethnic Groups

Rates of gestational diabetes increased significantly over the last decade in the U.S., according to a retrospective analysis.

Among over 12 million individuals included in the study, the overall age-standardized rate of gestational diabetes increased from 47.6 to 63.5 per 1,000 live births from 2011 to 2019 — an average increase of 3.7% per year, reported Sadiya Khan, MD, MSc, of Northwestern University’s Feinberg School of Medicine in Chicago, and colleagues.

These rates rose in all racial, ethnic, and age groups, the researchers wrote in JAMA.

The absolute rate of gestational diabetes was highest in Asian Indian participants (129.1 per 1,000 births in 2019), and this group was more than twice as likely to have gestational diabetes compared with white individuals (rate ratio [RR] 2.24, 95% CI 2.15-2.33).

These findings reinforce that it is “time to get serious about curbing increasing rates of gestational diabetes, particularly in pregnant people from racial and ethnic minority populations,” wrote Camille Powe, MD, of Massachusetts General Hospital in Boston, and Ebony Carter, MD, MPH, of Washington University School of Medicine in St. Louis, in an accompanying editorial.

During the “ongoing epidemic” of diabetes in the general population, findings of increased rates of gestational diabetes among nulliparous women are “particularly concerning,” they noted.

Shah’s group used data from the National Center for Health Statistics to define how rates of gestational diabetes changed over the last decade. They analyzed first live births in 12,610,235 people in the U.S. from 2011 to 2019.

Among the study participants, mean maternal age was 26.3; 21% identified as Hispanic, 8% as Asian or Pacific Islander, 14% as non-Hispanic Black, and 56% as non-Hispanic white. Nearly 90% of study participants completed at least a high school education, and almost all had insurance. Average age at delivery increased during the study period, from 25.5 to 27.

Compared with white participants, those who identified as Asian or Pacific Islander had nearly an 80% increased rate of gestational diabetes (RR 1.78, 95% CI 1.74-1.82).

There was a wide variation in gestational diabetes rates across subgroups of patients who identified as Asian or Pacific Islander, Khan told MedPage Today. Because subgroups such as Japanese, Filipino and Asian Indian, and others often are aggregated, it may be difficult to identify specific groups at risk, she said.

“It’s almost misleading to pool a group with that much difference into one category,” Khan pointed out. “You may actually miss out on the fact that there is a group that is disproportionately affected.”

Those who identified as Hispanic or Latina had rates 15% higher (RR 1.15, 95% CI 1.13-1.18) than white participants. However, Black participants had slightly lower rates (RR 0.97, 95% CI 0.94-0.99), which the authors said may be attributed to higher rates of pregestational diabetes.

Rates of pregestational diabetes at first birth also increased over the last decade, from 7.3 to 9.0 per 1,000 births. Compared with white patients, rates were 80% higher among Black patients (RR 1.80, 95% CI 1.71-1.90) and 40% higher in Hispanic or Latina patients (RR 1.38, 95% CI 1.31-1.44). Rates were not statistically significantly different among those in the Asian/Pacific Islander group.

Gestational diabetes increased during a time when risk factors such as overweight and obesity were also on the rise in the U.S., Powe and Carter noted. But while underlying causes of illness were outside of the scope of this study, “based on the observations from previous studies of racial and ethnic disparities in diabetes, many of the race-associated determinants of health that lead to inequities can be linked to systemic racism,” they wrote.

The experience of discrimination may also pose a risk of diabetes through a number of biological mechanisms, they added.

Shah’s group recognized that their analysis of trends that occurred before 2016 may be limited, as they only included states that adopted the 2003 birth certificate revision. Because some states adopted this revision during the study period (such as Hawaii, which adopted it in 2014), it may have affected results. Additionally, including only nulliparous patients may also skew results, as previous gestational diabetes is a risk factor for future illness.

Khan said future research should focus on factors driving the increases and disparities in gestational diabetes, as well as effective interventions for at-risk groups. But these data can help providers better inform patients of their individual risk.

“This can be clinically useful when thinking about whether these numbers and rates will help inform the patient in front of you,” she added.