Gestational diabetes mellitus (GDM) affects approximately 8 to 10 percent of U.S. pregnancies, according to CDC estimates, though some studies using more sensitive diagnostic criteria find rates as high as 14 percent. The prevalence has roughly doubled over the past two decades and varies substantially by age, race, ethnicity, and body mass index.
Current U.S. Prevalence
The CDC estimates that 8 to 10 percent of U.S. pregnancies are affected by gestational diabetes each year. National Vital Statistics data based on birth certificates reported 8.2 percent of births in 2021 were to women diagnosed with gestational diabetes, up from 6.0 percent in 2016 and roughly 3.5 percent in 2000.
Estimates vary by how gestational diabetes is diagnosed. The two-step approach (50 g glucose challenge followed by a 3-hour OGTT) used by most U.S. obstetricians yields 8-10 percent rates. The single-step 75 g OGTT approach recommended by the IADPSG can identify more cases, pushing rates to 14 percent or higher.
Trends Over Time
Gestational diabetes rates in the U.S. have roughly doubled since 2000. Several factors contribute:
- Rising maternal age. The average age at first birth has risen, and women over 35 have 2 to 3 times the risk.
- Higher pre-pregnancy BMI. Obesity rates among women of reproductive age have climbed steadily.
- Demographic shifts. Populations with higher baseline risk have grown.
- Expanded screening. More universal screening detects cases that were previously missed.
- Lower diagnostic thresholds. Some criteria revised over the years have increased case identification.
Rates by Race and Ethnicity
According to National Vital Statistics data, 2021 gestational diabetes rates by maternal race/ethnicity were roughly:
| Group | Rate (2021) |
|---|---|
| Asian | 14.9% |
| American Indian/Alaska Native | 10.1% |
| Native Hawaiian/Pacific Islander | 9.8% |
| Hispanic | 8.8% |
| Non-Hispanic White | 7.7% |
| Non-Hispanic Black | 6.8% |
Asian American women, particularly those of South Asian descent, show notably higher risk even at lower BMIs than other groups. Clinicians sometimes use lower BMI thresholds (23 or 25) for Asian women when assessing risk.
Rates by Maternal Age
Age is a strong risk factor. Pregnancy complicated by gestational diabetes rises with each decade of maternal age:
| Age Group | Approximate Rate |
|---|---|
| Under 25 | 3-5% |
| 25-29 | 6-8% |
| 30-34 | 9-11% |
| 35-39 | 12-15% |
| 40 and over | 15-20% |
Other Risk Factors
The ADA and ACOG list several factors that increase gestational diabetes risk:
- Pre-pregnancy BMI of 25 or higher (23 for Asian American women)
- Physical inactivity
- First-degree relative with diabetes
- Personal history of gestational diabetes or macrosomia (baby over 9 lb)
- Hypertension or cardiovascular disease
- HDL cholesterol below 35 mg/dL or triglycerides over 250 mg/dL
- Polycystic ovary syndrome
- A1C 5.7 percent or higher, or prior abnormal glucose testing
- Acanthosis nigricans or other signs of insulin resistance
If you already have prediabetes before pregnancy, your risk of developing gestational diabetes is substantially higher.
When Screening Happens
Standard screening occurs at 24 to 28 weeks of pregnancy. Women with multiple risk factors may be screened at the first prenatal visit. The two common approaches are:
- Two-step (more common in U.S.): 50 g 1-hour glucose challenge; if elevated, a 3-hour 100 g OGTT.
- One-step (used internationally): 75 g 2-hour OGTT with thresholds of 92, 180, and 153 mg/dL at 0, 1, and 2 hours.
Short-Term Risks of Gestational Diabetes
Uncontrolled gestational diabetes can increase the risk of:
- Macrosomia (large baby over 9 lb)
- Shoulder dystocia during delivery
- Neonatal hypoglycemia
- Preeclampsia and gestational hypertension
- Preterm birth
- Cesarean delivery
- Respiratory distress syndrome in the newborn
With diet, exercise, glucose monitoring, and sometimes insulin or metformin, most women achieve good control and deliver healthy babies.
Long-Term Risks for Mother and Child
Gestational diabetes is a strong predictor of future type 2 diabetes in the mother:
- About 50 percent develop type 2 diabetes within 10 years
- Up to 70 percent develop type 2 diabetes within 20 to 30 years
- Recurrence in a future pregnancy: 30 to 70 percent depending on the population
Children born to mothers with gestational diabetes have a higher risk of childhood obesity, metabolic syndrome, and type 2 diabetes later in life. Breastfeeding may reduce some of this risk.
Postpartum Follow-Up
The ADA suggests a 75 g oral glucose tolerance test 4 to 12 weeks after delivery to detect persistent glucose abnormalities. After that, women should be screened for diabetes every 1 to 3 years for life. Weight management, physical activity, and breastfeeding may help reduce the risk of future type 2 diabetes.
Our prediabetes treatment guide discusses lifestyle steps that may help lower long-term diabetes risk after a gestational diabetes diagnosis.
Global Comparison
Gestational diabetes rates vary globally. Estimates include roughly:
- United States: 8-10 percent
- Europe: 5-13 percent
- Southeast Asia: 10-25 percent
- Middle East and North Africa: 12-25 percent
- Sub-Saharan Africa: 9-14 percent
The International Diabetes Federation estimates about 14 percent of pregnancies worldwide are affected by some form of hyperglycemia in pregnancy, although criteria and screening coverage differ widely.
What Might Reduce Your Risk
While age, genetics, and race can’t be changed, some factors may lower risk:
- Achieving a healthy pre-pregnancy weight
- Getting regular physical activity before and during pregnancy
- Eating a diet rich in vegetables, fiber, lean protein, and healthy fats
- Managing PCOS or prediabetes before conceiving
- Gaining weight within recommended ranges during pregnancy
Always discuss exercise and diet plans during pregnancy with your obstetrician.
The Bottom Line
Gestational diabetes affects about 8 to 10 percent of U.S. pregnancies, and rates have been rising in parallel with maternal age and obesity. Asian, Hispanic, and American Indian women have higher prevalence. Most cases resolve after delivery, but about half of affected women develop type 2 diabetes within 10 years, making postpartum follow-up essential. Early screening, prenatal care, and lifestyle changes may help reduce risk and improve outcomes for both mother and baby.
