Gestational Diabetes:What do you need to know?

Gestational diabetes mellitus (GDM) is a type of diabetes that occurs during pregnancy, typically around 22 to 24 weeks of gestation. While most women can produce enough extra insulin to regulate blood sugar levels, about 5% of pregnant women develop GDM when their bodies cannot produce sufficient insulin to counteract the effects of pregnancy hormones. This leads to elevated blood sugar levels, posing potential health risks for both mother and baby.

What Causes Gestational Diabetes?

During pregnancy, the placenta plays a crucial role in supplying the foetus with nutrients, blood, and water from the mother. However, the placenta also produces certain hormones that can interfere with insulin function, a condition known as insulin resistance.

Insulin is a hormone responsible for helping cells absorb glucose from the bloodstream for energy. When insulin resistance develops, the body must produce more insulin to compensate. In a healthy pregnancy, this additional insulin production is usually sufficient to maintain normal blood sugar levels. However, in some women, the pancreas cannot produce enough insulin to meet the body’s increased demand, leading to gestational diabetes.

As pregnancy progresses, insulin resistance tends to increase, which is why GDM is commonly diagnosed in the second or third trimester. If left unmanaged, gestational diabetes can have serious consequences for both the mother and baby.

Risk Factors for Gestational Diabetes

Several factors can increase a woman’s risk of developing gestational diabetes, including:

  • Family history of diabetes: Women with a close relative (such as a parent or sibling) who has diabetes are at higher risk.
  • Previous history of gestational diabetes: If a woman has had GDM in a previous pregnancy, she is more likely to develop it again.
  • Being higher BMI: Excess weight can contribute to insulin resistance.
  • Polycystic ovary syndrome (PCOS): Women with PCOS often have insulin resistance, which increases the risk of GDM.
  • Age over 25: Older pregnant women are more likely to develop gestational diabetes.
  • Ethnic background: Indian women, along with women of Asian, African, and Hispanic descent, have a higher likelihood of developing GDM.

Symptoms of Gestational Diabetes

Gestational diabetes often does not cause noticeable symptoms, making screening essential. However, some women may experience:

  • Increased thirst
  • Frequent urination
  • Fatigue
  • Blurred vision
  • Increased hunger

Since these symptoms are common during pregnancy, they may not always indicate gestational diabetes. This is why all pregnant women, especially in India, are advised to undergo screening for diabetes as early as possible during pregnancy.

Screening and Diagnosis of GDM

Doctors typically screen for gestational diabetes between 24 and 28 weeks of pregnancy. However, women with higher risk factors may be screened earlier.

The two main tests used for diagnosing GDM are:

  1. Oral Glucose Tolerance Test (OGTT):
    • The pregnant woman drinks a glucose solution, and blood sugar levels are tested after one hour.
    • If the blood sugar level is high, a three-hour OGTT may be performed for confirmation.
  2. Fasting Blood Sugar and Postprandial Blood Sugar Tests:
    • These tests measure blood sugar levels after fasting and after eating a meal.
    • Elevated levels indicate gestational diabetes.

Effects of Gestational Diabetes on the Mother and Baby

If not managed properly, gestational diabetes can lead to complications for both the mother and the baby.

Risks for the Baby:

  • Macrosomia (large birth weight): High blood sugar levels cause the baby to grow excessively large, increasing the risk of complications during delivery.
  • Preterm birth: Babies of mothers with uncontrolled GDM are at a higher risk of being born prematurely.
  • Hypoglycaemia (low blood sugar) after birth: Babies may develop low blood sugar soon after delivery because they produce extra insulin.
  • Increased risk of obesity and type 2 diabetes later in life: Children born to mothers with GDM have a higher chance of developing diabetes and obesity in the future.

Risks for the Mother:

  • High blood pressure and preeclampsia: GDM increases the risk of hypertension and a serious condition called preeclampsia, which can be life-threatening.
  • Higher risk of caesarean delivery: Due to the increased likelihood of having a large baby, women with GDM are more likely to require a C-section.
  • Increased risk of type 2 diabetes: Women who develop GDM are at a higher risk of developing type 2 diabetes later in life.

 

Managing Gestational Diabetes

The good news is that gestational diabetes can be effectively managed with lifestyle changes, medication, and regular monitoring.

  1. Healthy Diet:
  • Balanced meals: A diet rich in whole grains, lean proteins, healthy fats, and plenty of fibre can help regulate blood sugar levels.
  • Portion control: Eating smaller, frequent meals helps prevent blood sugar spikes.
  • Limiting sugar intake: Reducing the consumption of sweets, sugary drinks, and processed foods is essential.
  1. Regular Physical Activity:
  • Engaging in at least 30 minutes of moderate exercise, such as walking, yoga, or prenatal aerobics, can help improve insulin sensitivity.
  • Physical activity helps in maintaining healthy blood sugar levels and reducing the risk of complications.
  1. Monitoring Blood Sugar Levels:
  • Regular blood sugar checks at home help track glucose levels and allow timely intervention if needed.
  • Keeping blood sugar levels within the recommended range is crucial for a healthy pregnancy.
  1. Medication and Insulin Therapy:
  • In some cases, diet and exercise alone may not be enough to control blood sugar levels.
  • Doctors may prescribe insulin therapy or oral medications to help maintain normal glucose levels.

Postpartum Care and Future Health Risks

Gestational diabetes usually disappears after childbirth. However, women who have had GDM are at a higher risk of developing type 2 diabetes later in life.

Postpartum Guidelines:

  • Blood sugar testing after delivery: A follow-up glucose test is recommended 6-12 weeks after childbirth to ensure blood sugar levels have returned to normal.
  • Maintaining a healthy lifestyle: Eating a balanced diet, staying physically active, and maintaining a healthy weight can help reduce the risk of future diabetes.
  • Regular health check-ups: Women who have had GDM should undergo regular diabetes screenings at least every 1 to 3 years.

Conclusion

Gestational diabetes is a significant medical condition that requires careful monitoring and management. While it poses risks to both mother and baby, early detection and proper management can help ensure a healthy pregnancy and delivery.

Since GDM is a strong predictor of future type 2 diabetes and cardiovascular diseases, women with a history of GDM should adopt a lifelong commitment to a healthy lifestyle to reduce future health risks.

By raising awareness and encouraging early screening, we can help more women manage gestational diabetes effectively and ensure the well-being of both mothers and their babies.

Dr. Honey Evangelin M, Consultant
Dr. Mohan’s Diabetes Specialities Centre
Porur, Chennai