It’s estimated that gestational diabetes (GDM) affects up to 6-9% of pregnant women, but what exactly what is this condition? Gestational diabetes is a type of diabetes that can occur in pregnant women. It begins in middle pregnancy and therefore, is typically tested for at the 24-28 week mark of pregnancy. Learn more about gestational diabetes below, including its causes, risk factors, potential complications and the testing process for diagnosis.  


What Causes Gestational Diabetes?

The body produces specific pregnancy hormones throughout pregnancy that can interfere with insulin (this is the hormone that helps sugar move from the blood stream to the body’s cells). Typically, the body can produce more insulin to compensate for pregnancy hormones making it difficult for insulin to do its job, but sometimes the body is not able to make enough. This causes blood sugar levels to rise and can lead to gestational diabetes.


Risk Factors for GDM

Risk factors for gestational diabetes include:

  • Overweight or obese
  • Physical inactivity
  • Ethnicity: African American, Hispanic/Latino American, American Indian, Alaska Native, Native Hawaiian, or Pacific Islander
  • Age – namely being older than 25 years old
  • Family history of type 2 diabetes
  • Previous diagnosis of gestational diabetes in prior pregnancy
  • Previous birth of a baby greater than 9 pounds
  • Polycystic ovarian syndrome


GDM Complications that may affect your baby

Some potential complications of uncontrolled GDM include:

  • Excessive birth weight. Higher than normal blood sugar in mothers can cause their babies to grow too large. Very large babies — those who weigh 9 pounds or more — are more likely to become wedged in the birth canal, have birth injuries or need a C-section birth.
  • Early (preterm) birth. High blood sugar may increase women’s risk of early labor and delivery before the due date. Or early delivery may be recommended because the baby is large.
  • Serious breathing difficulties. Babies born early to mothers with gestational diabetes may experience respiratory distress syndrome — a condition that makes breathing difficult.
  • Low blood sugar (hypoglycemia). Sometimes babies of mothers with gestational diabetes have low blood sugar (hypoglycemia) shortly after birth. Severe episodes of hypoglycemia may cause seizures in the baby. Prompt feedings and sometimes an intravenous glucose solution can return the baby’s blood sugar level to normal.
  • Obesity and type 2 diabetes later in life. Babies of mothers who have gestational diabetes have a higher risk of developing obesity and type 2 diabetes later in life.
  • Untreated gestational diabetes can result in a baby’s death either before or shortly after birth.

How to Test For Gestational Diabetes

The accepted methods to test for and diagnose GDM are:

  • Glucose Challenge Test: Sometimes known as the glucose screening test. Typically, this is the first test performed when screening for gestational diabetes. In this test, a health care professional will draw your blood 1 hour after you drink a sweet liquid containing glucose. You do not need to fast for this test, meaning you can eat and drink as usual before the testing.  (Fasting means having nothing to eat or drink except water.) If your blood glucose is too high—140 or more—you may need to return for an oral glucose tolerance test while fasting.
  • Oral Glucose Tolerance Test (OGTT): The OGTT measures blood glucose after you fast for at least 8 hours. First, a health care professional will draw your blood. Then, you will drink the liquid containing glucose. You will need your blood drawn every hour for 2 to 3 hours, for a total of four blood draws, for a doctor to diagnose gestational diabetes. Having elevated blood glucose at any two of the four blood draws could determine a diagnosis of diabetes.
    • A normal fasting blood glucose level is lower than 95 mg/dL
    • After drinking the glucose solution a normal blood glucose is:
      • One hour: lower than 180 mg/dL
      • Two hours: lower than 155 mg/dL
      • Three hours: lower than 140 mg/dL

While gestational diabetes may seem scary, the biggest weapon is knowledge. Stay tuned for further information about what to expect if you’ve been diagnosed with gestational diabetes and how to successfully manage it.