What Should You Do if You Are Diagnosed With Gestational Diabetes?
Start monitoring your blood sugar levels as directed by your healthcare team, typically four times daily: fasting and one to two hours after each meal. Meet with a registered dietitian specializing in gestational diabetes to develop a meal plan. Begin daily physical activity such as walking for 15 to 30 minutes after meals. Most women can successfully manage gestational diabetes with these lifestyle changes alone.
The first step after a gestational diabetes diagnosis is blood glucose monitoring. Your healthcare team will provide a glucose meter and teach you to check fasting glucose each morning and postprandial (after-meal) glucose one to two hours after the start of each meal. The ADA targets are fasting below 95 mg/dL, 1-hour postprandial below 140 mg/dL, and 2-hour postprandial below 120 mg/dL. Record all values in a log to share with your team at each visit. Consistent monitoring helps identify which foods and activities affect your blood sugar and guides treatment decisions.
Medical nutrition therapy is the cornerstone of gestational diabetes management. A registered dietitian will help you develop a meal plan that provides adequate nutrition for you and your growing baby while controlling blood sugar. General guidelines include distributing carbohydrates evenly across three meals and two to three snacks, choosing complex carbohydrates over refined sugars, pairing carbohydrates with protein and healthy fats to slow glucose absorption, and eating a small bedtime snack to prevent overnight fasting hypoglycemia. Most women need about 30 to 35 calories per kilogram of ideal body weight, with adjustments based on pre-pregnancy BMI.
Physical activity is an effective complement to dietary management. The American College of Obstetricians and Gynecologists recommends 30 minutes of moderate-intensity exercise on most days of the week for pregnant women without medical contraindications. Walking after meals has been shown to significantly reduce postprandial glucose peaks. Swimming, stationary cycling, and prenatal yoga are also safe options. Always consult your obstetrician before starting a new exercise program during pregnancy.
The ADA recommends blood sugar targets during pregnancy of fasting below 95 mg/dL and 1-hour postprandial below 140 mg/dL
What Is Gestational Diabetes and How Common Is It?
Gestational diabetes mellitus is a form of diabetes first diagnosed during the second or third trimester of pregnancy in women who did not have diabetes before conception. The CDC reports that gestational diabetes affects 2 to 10 percent of pregnancies in the United States, with prevalence increasing due to rising rates of obesity and maternal age.
During pregnancy, the placenta produces hormones essential for fetal development, including human placental lactogen, cortisol, estrogen, and progesterone. These hormones progressively increase insulin resistance, particularly during the second and third trimesters. In most women, pancreatic beta cells compensate by producing two to three times more insulin than normal. Gestational diabetes develops when the pancreas cannot meet this increased demand. The Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study, a landmark international multicenter study involving over 23,000 pregnant women, demonstrated a continuous relationship between maternal glucose levels and adverse outcomes, with no clear threshold.
Risk factors for gestational diabetes include pre-pregnancy overweight or obesity (BMI of 25 or higher), age 25 or older, family history of type 2 diabetes, personal history of gestational diabetes in a previous pregnancy, polycystic ovary syndrome, previously delivering a baby weighing 9 pounds or more, and belonging to certain ethnic groups including Hispanic, African American, Native American, South Asian, or Pacific Islander. The International Diabetes Federation estimates that approximately 21 million live births worldwide were affected by hyperglycemia in pregnancy in 2021.
The HAPO study, involving over 23,000 pregnant women, demonstrated a continuous relationship between maternal glucose and adverse outcomes
How Is Gestational Diabetes Screened and Diagnosed?
The most common screening approach in the United States is a two-step process: a 1-hour 50-gram glucose challenge test at 24 to 28 weeks, followed by a 3-hour 100-gram oral glucose tolerance test if the initial screen is abnormal. An alternative one-step approach uses a 2-hour 75-gram OGTT based on IADPSG criteria.
The two-step approach begins with a non-fasting 50-gram glucose challenge test. Blood sugar is measured one hour after drinking the glucose solution. A result of 130 or 140 mg/dL or higher (threshold varies by practice) indicates the need for a confirmatory 3-hour 100-gram OGTT. For the 3-hour test, fasting glucose is measured, the patient drinks a 100-gram glucose solution, and blood sugar is checked at 1, 2, and 3 hours. Gestational diabetes is diagnosed if two or more values meet or exceed the Carpenter-Coustan thresholds: fasting 95 mg/dL, 1-hour 180 mg/dL, 2-hour 155 mg/dL, 3-hour 140 mg/dL.
The International Association of Diabetes and Pregnancy Study Groups (IADPSG) recommends a one-step approach using a fasting 75-gram OGTT with lower diagnostic thresholds (fasting 92 mg/dL, 1-hour 180 mg/dL, 2-hour 153 mg/dL), with only one abnormal value required for diagnosis. This approach diagnoses more women with gestational diabetes and is used by the WHO and many international guidelines. The ACOG continues to recommend the two-step approach as the primary strategy in the United States due to concerns about overdiagnosis and increased intervention with the one-step approach. Women with high risk factors should be tested at their first prenatal visit for pre-existing diabetes.
ACOG recommends the two-step screening approach for gestational diabetes in the United States
What Are the Risks of Gestational Diabetes for Mother and Baby?
Uncontrolled gestational diabetes increases risks for both mother and baby. Maternal risks include preeclampsia, cesarean delivery, and future type 2 diabetes. Fetal and neonatal risks include macrosomia (large birth weight), birth injuries, neonatal hypoglycemia, respiratory distress, jaundice, and increased long-term risk of childhood obesity and diabetes.
For the baby, the primary risk of uncontrolled gestational diabetes is macrosomia, defined as birth weight above 4,000 grams (8 pounds 13 ounces). Excess maternal glucose crosses the placenta and stimulates the fetal pancreas to produce more insulin, which acts as a growth factor driving excessive fetal growth. Macrosomia increases the risk of shoulder dystocia (where the baby's shoulder gets stuck during delivery), birth injuries including brachial plexus injury, and cesarean delivery. After birth, the baby's high insulin levels persist while maternal glucose supply stops, potentially causing neonatal hypoglycemia. Neonatal jaundice, respiratory distress syndrome, and polycythemia are also more common in infants of mothers with poorly controlled gestational diabetes.
For the mother, gestational diabetes increases the risk of hypertensive disorders of pregnancy, including preeclampsia, by approximately two to four fold. Labor complications from fetal macrosomia may require cesarean delivery, which carries its own surgical risks. The most significant long-term risk is the dramatically elevated probability of developing type 2 diabetes after pregnancy. A meta-analysis published in Lancet found that women with prior gestational diabetes have a seven-fold higher risk of developing type 2 diabetes compared to women with normoglycemic pregnancies. The risk is highest in the first five years postpartum but persists for decades.
A Lancet meta-analysis found that women with prior gestational diabetes have a seven-fold higher risk of developing type 2 diabetes
What Should You Eat With Gestational Diabetes?
A gestational diabetes meal plan focuses on distributing carbohydrates evenly throughout the day, choosing complex carbohydrates with low glycemic index, combining carbohydrates with protein and healthy fats, and eating consistent meals and snacks. Working with a registered dietitian who specializes in gestational diabetes is the most effective approach.
Carbohydrate management is the cornerstone of the gestational diabetes diet. Total carbohydrate intake is typically limited to 35 to 45 percent of total calories, distributed across three meals and two to three snacks. Breakfast carbohydrates often need to be most restricted because insulin resistance tends to be highest in the morning. Choosing low-glycemic-index foods such as whole grains, legumes, most fruits, and non-starchy vegetables helps prevent postprandial glucose spikes. Pairing carbohydrates with protein (eggs, cheese, nuts, lean meat) and healthy fats (avocado, olive oil) slows glucose absorption and promotes satiety.
Adequate nutrition for both mother and baby remains the priority. Caloric needs during pregnancy increase by approximately 340 to 450 calories per day in the second and third trimesters. Key nutrients include folate, iron, calcium, vitamin D, DHA omega-3 fatty acids, and adequate protein (at least 71 grams per day). Avoid skipping meals, which can cause rebound hyperglycemia, and avoid going longer than 10 hours overnight without eating. A bedtime snack containing protein and complex carbohydrate helps prevent overnight fasting ketosis. The Academy of Nutrition and Dietetics recommends that all women with gestational diabetes receive individualized medical nutrition therapy from a registered dietitian.
When Is Medication Needed for Gestational Diabetes?
Medication is needed when blood sugar levels remain above target despite one to two weeks of dietary and lifestyle management. Approximately 15 to 30 percent of women with gestational diabetes require insulin or oral medication. Insulin is the preferred pharmacotherapy because it does not cross the placenta and provides the most precise glucose control.
Insulin is the gold standard pharmacological treatment for gestational diabetes when lifestyle measures are insufficient. Rapid-acting insulin analogs (lispro or aspart) before meals and intermediate-acting (NPH) or long-acting (detemir) insulin for basal coverage are commonly used. Insulin doses are carefully titrated based on blood sugar patterns, with frequent adjustments as pregnancy progresses and insulin resistance increases. The ADA emphasizes that insulin requirements may increase significantly in the third trimester and then drop sharply after delivery, requiring close monitoring to prevent hypoglycemia.
Metformin and glyburide are sometimes used as alternatives to insulin for gestational diabetes, though both cross the placenta. The MiG trial (Metformin in Gestational Diabetes) showed that metformin was not inferior to insulin for perinatal outcomes, though 46 percent of women assigned to metformin also required supplemental insulin. Metformin is classified as a reasonable alternative by the ADA for women who decline or cannot afford insulin. Glyburide use has decreased due to studies showing higher rates of neonatal hypoglycemia and macrosomia compared to insulin. The choice between insulin and oral agents should be a shared decision between the patient and her healthcare team.
The MiG trial showed metformin was not inferior to insulin for perinatal outcomes, though 46 percent of women required supplemental insulin
What Happens After Delivery With Gestational Diabetes?
Blood sugar levels typically normalize within hours to days after delivery. However, postpartum follow-up is critical because of the high future diabetes risk. The ADA recommends glucose testing at 4 to 12 weeks postpartum using a 75-gram OGTT, followed by screening every 1 to 3 years for life using A1C, fasting glucose, or OGTT.
Immediately after delivery, insulin or other diabetes medications are usually discontinued because insulin resistance drops rapidly once the placenta is delivered. Blood sugar should be monitored in the immediate postpartum period to confirm normalization. If glucose levels remain elevated, the patient may have pre-existing type 2 diabetes that was unmasked during pregnancy rather than true gestational diabetes. The ADA recommends postpartum glucose testing at 4 to 12 weeks using the 75-gram OGTT, which is more sensitive than fasting glucose or A1C for detecting postpartum glucose abnormalities.
Long-term follow-up is essential. The cumulative risk of developing type 2 diabetes after gestational diabetes ranges from 15 to 70 percent depending on the population and follow-up duration. Lifestyle intervention remains highly effective in this population: the DPP trial showed that women with a history of gestational diabetes who completed the lifestyle intervention had a 35 percent lower risk of developing type 2 diabetes. Breastfeeding may also provide protective benefits, with some studies suggesting a 25 to 47 percent reduction in diabetes risk among women who breastfeed for at least three months. Planning for future pregnancies should include preconception glucose testing and weight optimization.
The ADA recommends postpartum glucose testing at 4 to 12 weeks and then every 1 to 3 years for women with prior gestational diabetes
How Can You Reduce Your Risk of Gestational Diabetes Recurrence?
Women who have had gestational diabetes have a 30 to 70 percent chance of recurrence in subsequent pregnancies. Reducing risk involves achieving a healthy weight before pregnancy, maintaining regular physical activity, following a balanced diet, and working closely with your healthcare team for early prenatal screening and proactive management.
Preconception health optimization is the most effective strategy for reducing gestational diabetes recurrence. Achieving a BMI in the normal range (18.5 to 24.9) before pregnancy significantly lowers risk. Even modest weight loss of 5 to 10 percent of body weight between pregnancies is beneficial if normal BMI is not achievable. Interpregnancy weight gain is a strong predictor of recurrence, with studies showing that gaining more than 3 BMI units between pregnancies substantially increases risk. The ADA recommends preconception counseling for all women with prior gestational diabetes.
Lifestyle modifications between pregnancies mirror those recommended for diabetes prevention. Engaging in at least 150 minutes per week of moderate-intensity physical activity, following a Mediterranean or DASH-style dietary pattern, ensuring adequate sleep, managing stress, and avoiding excessive weight gain during pregnancy all contribute to reducing risk. Women with prior gestational diabetes should be screened for diabetes before conception to ensure normal glucose levels at the time of pregnancy. If preconception glucose testing reveals prediabetes or diabetes, treatment should be optimized before pregnancy to reduce risks of congenital anomalies and early pregnancy complications.
