Gestational Diabetes: Symptoms, Causes, and Treatment

Gestational diabetes is high blood sugar that starts during pregnancy. It affects how your cells use sugar and can lead to complications if untreated. Regular prenatal screening catches it early. Management focuses on diet, exercise, and sometimes medication. Most women's blood sugar returns to normal after delivery, but they remain at higher risk for type 2 diabetes later.

In plain words

Gestational diabetes is high blood sugar that starts during pregnancy. It happens when your body can't make enough insulin to control blood sugar. Insulin is a hormone that helps your body use sugar for energy. This type of diabetes usually goes away after the baby is born. But it needs to be managed during pregnancy to keep mom and baby healthy. Most women don't feel sick, but some may feel very thirsty, need to urinate often, or feel extra tired. Doctors test for it between weeks 24 and 28 of pregnancy. Treatment includes eating healthy foods, staying active, and checking blood sugar. Some women may need insulin shots to help control their blood sugar. After delivery, blood sugar usually returns to normal, but women who had gestational diabetes are more likely to develop type 2 diabetes later in life.

What is Gestational Diabetes: Symptoms, Causes, and Treatment?

Gestational diabetes is high blood sugar that starts during pregnancy. It affects how your cells use sugar and can lead to complications if untreated. Regular prenatal screening catches it early. Management focuses on diet, exercise, and sometimes medication. Most women's blood sugar returns to normal after delivery, but they remain at higher risk for type 2 diabetes later.

Symptoms

Early symptoms

  • Often no noticeable symptoms: Many women with gestational diabetes don't experience obvious symptoms. That's why screening tests during pregnancy are so important. (2) (5)
  • Increased thirst: Drinking more fluids than usual, even when not active or in hot weather. This happens when high blood sugar pulls fluid from tissues. (2)
  • Frequent urination: Needing to urinate more often, including waking up at night. The kidneys work harder to filter excess sugar from blood. (2) (5)
  • Fatigue: Feeling more tired than expected during pregnancy. Sugar not entering cells properly means less energy production. (2)
  • Sugar in urine (detected at prenatal visits): Found during routine urine tests at checkups. Not all women with sugar in urine have gestational diabetes, but it warrants testing. (5)

Serious or emergency symptoms

  • Blurred vision: High blood sugar can cause temporary swelling in the eyes' lenses. This is uncommon but requires immediate medical attention. Contact your obstetrician or midwife promptly if vision changes suddenly. (2)

Causes

Primary causes

  • Pregnancy hormones affecting insulin: Hormones from the placenta help the baby grow but can block insulin action in the mother. This insulin resistance makes blood sugar rise. (1)
  • Pancreas can't keep up with demand: Normally, the pancreas makes extra insulin to overcome resistance. In gestational diabetes, it doesn't produce enough. (1)

Risk factors

Being overweight before pregnancy

Excess weight increases insulin resistance. BMI over 30 particularly raises risk but doesn't guarantee gestational diabetes. (1) (6)

Previous gestational diabetes

Women who had it in prior pregnancies have a 30-70% chance of developing it again. Risk rises with each affected pregnancy. (1)

Family history of type 2 diabetes

Close relatives with diabetes suggest genetic predisposition to insulin problems. (6)

Age over 25

Risk increases steadily after age 25. Over 35 is considered higher risk. (1)

Certain ethnic backgrounds

Higher rates occur in African-American, Hispanic, Native American, South/ East Asian, and Pacific Islander women. (6)

Diagnosis

Gestational diabetes is typically diagnosed between 24-28 weeks of pregnancy using an oral glucose tolerance test (OGTT). You'll fast overnight, then drink a glucose solution. Blood tests measure sugar levels at fasting, one hour, and two hours after drinking. Higher than normal results at two or more points indicate gestational diabetes. Some doctors use a simpler one-step test or an initial glucose challenge test followed by OGTT if screening is positive. High-risk women may be tested earlier.

Oral glucose tolerance test (OGTT)

Measures how well your body processes sugar after fasting. The gold standard diagnostic test for gestational diabetes. (3) (5)

Glucose challenge screening

Initial one-hour test where you drink glucose and have blood drawn after. Only abnormal results require follow-up OGTT. (3)

Treatment

Medication options

Insulin therapy

Injected insulin helps control blood sugar when diet and exercise aren't enough. It doesn't cross the placenta to the baby. (4)

Oral diabetes medications

Some pills like metformin can be used off-label when insulin isn't an option. They help lower blood sugar production in the liver. (4)

Lifestyle and self-care

  • Healthy eating plan: A registered dietitian can create a meal plan with balanced carbohydrates, lean proteins and healthy fats. Spread carb intake evenly through the day to avoid large blood sugar spikes. (4) (7) (8)
  • Regular physical activity: 30 minutes of moderate exercise (like walking or swimming) most days helps lower blood sugar. Always check with your doctor about safe exercise during pregnancy. (7) (8)
  • Blood sugar monitoring: Checking levels with a glucose meter at home helps track what affects your blood sugar. Your care team will teach you how and when to test. (4) (8)
  • Attend all prenatal visits: More frequent monitoring ensures tight blood sugar control. Your doctor may order additional ultrasounds to track baby's growth. (7)

Always discuss dosing and treatment changes with your own prescriber.

Possible complications

  • Large baby (macrosomia): Extra glucose crossing the placenta makes the baby grow larger than average. This can lead to difficult delivery, birth injuries, or need for C-section. (6) (7)
  • Neonatal hypoglycemia: Babies may have low blood sugar after birth since they're used to high sugar levels from mom. This requires monitoring and sometimes treatment. (7)
  • Preterm birth: Higher risk of early delivery, often due to baby being large or other metabolic strains on the pregnancy. (6)
  • Future type 2 diabetes: About half of women with gestational diabetes develop type 2 diabetes within 5-10 years post-pregnancy without lifestyle changes. (6)

When to see a doctor

Routine follow-up

  • Schedule a visit if you have risk factors for gestational diabetes before your scheduled glucose test at 24-28 weeks. Early detection helps prevent complications. (3)
  • Discuss any concerning symptoms like unusual thirst or increased urination at your next prenatal appointment—don't wait until the next scheduled visit. (2)

Seek emergency care

  • Seek urgent care for signs of very high blood sugar like severe nausea/vomiting, excessive fatigue, or rapid breathing—these may indicate uncontrolled diabetes requiring immediate treatment. (2)
  • Call your healthcare provider immediately if your blood sugar readings are consistently above your target range despite following your management plan. (4)

Frequently asked questions

Does gestational diabetes mean my baby will be born with diabetes?

No. Gestational diabetes affects mom's blood sugar during pregnancy but doesn't mean baby is born with diabetes. However, uncontrolled high blood sugar can affect baby's development and increase their future diabetes risk. (8) (5)

Will I need diabetes medication during pregnancy?

About 30% of women need insulin when diet and exercise alone don't control blood sugar. Your doctor will help decide what's best for you and baby. Medication needs depend on your glucose levels and pregnancy progression. (4)

Can gestational diabetes turn into type 1 or type 2 diabetes?

It doesn't become type 1 diabetes but does raise type 2 risk. Type 1 is an autoimmune condition unrelated to pregnancy. About 50% of gestational diabetes patients develop type 2 later without lifestyle changes. (8)

How soon after delivery will gestational diabetes go away?

Blood sugar usually returns to normal within hours to weeks after birth. You'll have a glucose test 6-12 weeks postpartum to confirm. Over half resolve immediately, but all require long-term monitoring. (5)

Is gestational diabetes my fault?

No. It happens due to pregnancy hormones affecting insulin resistance, not from anything you did. While lifestyle factors influence risk, placenta-derived hormones are the primary cause. Focus on working with your care team to manage it. (1)

References

  1. CDC — Gestational Diabetes source 1
  2. NHS — Gestational diabetes - Symptoms source 2
  3. NHS — Gestational diabetes - Diagnosis source 3
  4. NHS — Gestational diabetes - Treatment source 4
  5. MedlinePlus — Gestational Diabetes source 5
  6. WHO — Diabetes Fact Sheet source 6
  7. CDC — Managing Gestational Diabetes source 7
  8. NHS — Living with Gestational Diabetes source 8