About 1 in 6 pregnancies worldwide are affected by gestational diabetes, making it one of the most common complications of pregnancy. In the United States, 8.3% of mothers who gave birth in 2021 received a gestational diabetes diagnosis, up from 6.0% in 2016. Those numbers have been climbing steadily, driven by rising maternal age, increasing rates of obesity, and broader screening practices.
Rates in the United States
The most recent CDC data shows gestational diabetes affected roughly 1 in 12 U.S. pregnancies in 2021. That’s a nearly 40% increase in just five years. The rise isn’t explained by a single factor, but the trend is consistent across age groups and demographic backgrounds.
Age plays a dramatic role. In 2021, 15.6% of mothers aged 40 and older had gestational diabetes, nearly six times the rate among mothers under 20 (2.7%). Rates also vary significantly by race and ethnicity. Asian American women had the highest rate at 14.9%, followed by American Indian/Alaska Native women at 11.8%, Native Hawaiian/Pacific Islander women at 10.6%, Hispanic women at 8.5%, non-Hispanic White women at 7.0%, and non-Hispanic Black women at 6.5%.
These disparities reflect a mix of genetic predisposition, differences in access to prenatal care, and variation in other risk factors like diet and body composition. Asian women, for example, tend to develop insulin resistance at lower body weights than other groups, which partly explains the higher rates even among those who aren’t overweight by standard BMI cutoffs.
Who Is Most at Risk
Maternal age is one of the strongest predictors. A meta-analysis covering over 120 million pregnancies found that risk rises in a near-linear pattern with each year of age. Compared to women aged 25 to 29, women in their early 30s are about 1.7 times more likely to develop gestational diabetes. By ages 35 to 39, the risk roughly triples. Women 40 and older face nearly five times the risk. For every additional year of maternal age starting at 18, the overall risk increases by about 8%.
Pre-pregnancy weight is the other major factor. Women who are obese before becoming pregnant are about 3.5 times more likely to develop gestational diabetes than women at a normal weight. This is because excess body fat makes cells less responsive to insulin, and pregnancy already puts significant strain on the body’s ability to regulate blood sugar. When those two pressures combine, the pancreas often can’t keep up.
Other factors that raise risk include a family history of type 2 diabetes, having had gestational diabetes in a previous pregnancy, polycystic ovary syndrome, and carrying multiples (twins or more).
What Happens During Pregnancy
Gestational diabetes develops when the body can’t produce enough insulin to handle the extra demands of pregnancy. During the second and third trimesters, the placenta releases hormones that make cells throughout the body more resistant to insulin. In most pregnancies, the pancreas compensates by producing more. When it can’t, blood sugar levels rise.
Most women are screened between 24 and 28 weeks of pregnancy with a glucose challenge test. You drink a sugary solution and have your blood drawn afterward. If levels are elevated, a longer follow-up test confirms the diagnosis. Women with significant risk factors may be screened earlier.
Gestational diabetes usually doesn’t cause noticeable symptoms, which is why routine screening matters. Left unmanaged, elevated blood sugar can lead to a larger-than-average baby (increasing the chance of a difficult delivery or cesarean section), low blood sugar in the newborn after birth, and a higher risk of preeclampsia for the mother.
Managing It During Pregnancy
The good news is that gestational diabetes is highly manageable. Most women control their blood sugar through dietary changes and regular physical activity. The focus is typically on eating smaller, more frequent meals, pairing carbohydrates with protein or fat to slow sugar absorption, and choosing complex carbs over refined ones. Regular walking or other moderate exercise helps cells use insulin more effectively.
You’ll monitor your blood sugar at home, usually by pricking your finger several times a day. If diet and exercise aren’t enough to keep levels in range, insulin or oral medication may be needed. About 10% to 20% of women with gestational diabetes require medication.
Blood sugar levels typically return to normal within days of delivery. Your doctor will check again at your postpartum visit to confirm.
Recurrence in Future Pregnancies
If you’ve had gestational diabetes once, there’s roughly a 50% chance it will come back in a subsequent pregnancy. A large meta-analysis found a pooled recurrence rate of 50.7%, though individual studies reported rates ranging from about 31% to 74% depending on the population. Factors that increase recurrence include gaining significant weight between pregnancies, being diagnosed earlier in the first pregnancy, and needing insulin to manage blood sugar the first time around.
Long-Term Risk of Type 2 Diabetes
Gestational diabetes is also a signal about your metabolic health beyond pregnancy. Within the first five years after diagnosis, about 8% of women go on to develop type 2 diabetes. After five years, that number rises to roughly 19%. Over a lifetime, women who had gestational diabetes face up to a sevenfold increase in type 2 diabetes risk compared to women who didn’t.
This doesn’t mean type 2 diabetes is inevitable. The same strategies that help during pregnancy, maintaining a healthy weight, staying physically active, and eating a balanced diet, significantly reduce the risk. Postpartum glucose screening at 6 to 12 weeks and then every one to three years helps catch any changes early, when they’re easiest to address.
Almost half of all gestational diabetes cases globally occur in women under 30, which means this isn’t only a concern for older mothers. For younger women, the long-term window for developing type 2 diabetes is even longer, making follow-up care especially important.