Prevalence of pregestational diabetes increased since 2000, increases pregnancy risks

From 2000 to 2019, the prevalence of type 2 diabetes quadrupled, increasing the overall prevalence of pregestational diabetes. The rise in pregestational diabetes increased the odds of adverse pregnancy outcomes, researchers reported.

“Prior population-level analyses using administrative data found that pregestational diabetes increased approximately 50% from 1993 to 2009, consistent with the increase in diabetes prevalence among all U.S. adults in the same time period,” Lindsey P. Gorsch, BA, a student at Columbia University Vagelos College of Physicians and Surgeons in New York City, and colleagues wrote. “It is likely that pregestational diabetes has continued to increase in the obstetric population as risk factors such as obesity and advanced maternal age are becoming more prevalent.”

Gorsch and colleagues analyzed the U.S. National Inpatient Sample to identify 76.7 million delivery hospitalizations from 2000 to 2019. The researchers included patients aged 15 to 54 years in analyses and classified them based on diabetes status.

The primary outcome was trends in delivery hospitalizations involving patients with pregestational diabetes. Gorsch and colleagues evaluated pregnancy outcomes associated with pregestational diabetes as a secondary outcome.

Delivery hospitalization trends

In total, there was a diagnosis of type 1 diabetes for 179,885 (0.23%) deliveries, a type 2 diabetes diagnosis for 430,544 (0.56%) deliveries, a gestational diabetes diagnosis for 4,518,330 (5.9%) deliveries and an unspecified diabetes diagnosis for 99,327 (0.13%) deliveries.

From 2000 to 2019, the prevalence of type 2 diabetes increased from 1.8 to 7.3 per 1,000 births (average annual percent change [AAPC] = 8%; 95% CI, 6.9-9.2), the prevalence of unspecified diabetes increased from 1.5 to 3.2 per 1,000 births (AAPC = 3.9%; 95% CI, 1.4-6.3) and the prevalence of gestational diabetes increased from 35 to 85.6 (AAPC = 4.4%; 95% CI, 4.1-4.6). The prevalence of type 1 diabetes did not increase significantly.

Among deliveries with pregestational diabetes, the rate of chronic diabetes complications — which included chronic kidney disease, neuropathy, peripheral vascular disease and diabetic retinopathy — increased from 2.7% to 5.6% (AAPC = 5.9%; 95% CI, 3.7-8).

Adverse pregnancy outcomes

In terms of pregnancy outcomes, all diagnoses of diabetes were associated with higher odds of non-transfusion severe maternal morbidity, cardiac severe maternal morbidity, preterm birth, cesarean delivery and hypertensive disorders of pregnancy. All diabetes diagnoses in vaginal deliveries were associated with greater odds of shoulder dystocia and obstetric anal sphincter injury.

Type 2 diabetes was associated with the highest odds for non-transfusion severe maternal morbidity (adjusted OR = 2.68; 95% CI, 2.49-2.9), preterm birth (aOR = 3.4; 95% CI, 3.29-3.52), cesarean delivery (aOR = 4.37; 95% CI, 4.26-4.48), hypertensive disorders of pregnancy (aOR = 3.62; 95% CI, 3.52-3.72), shoulder dystocia (aOR = 4.75; 95% CI, 4.47-5.06) and obstetric anal sphincter injury (aOR = 1.78; 95% CI, 1.65-1.92).

The odds of cardiac severe maternal morbidity were highest among deliveries with diagnoses of unspecified diabetes (aOR = 2.74; 95% CI, 2.31-3.24).

“These findings support that pregestational diabetes is an important contributor to maternal risk and that optimizing care will continue to be of major public health importance,” Gorsch and colleagues wrote.