Gestational Diabetes: The Fact File

Gestational Diabetes Mellitus is the development of high blood sugar levels during pregnancy. It occurs in about 4% of all pregnancies. It is typically diagnosed in the later months of pregnancy and often occurs in women who have no prior history of diabetes.


The two main aspects of the underlying pathology is insulin resistance as well as impaired glucose tolerance, where the body’s cells fail to respond to the hormone insulin in the usual way.

Several pregnancy hormones are thought to disrupt the usual action of insulin as it binds to its receptor, most probably by interfering with the cell signaling pathways. Insulin is a hormone made by specialized cells of the pancreas that allows the body to metabolize glucose for later usage as fuel (energy). When levels of insulin are low, or when the body cannot effectively use insulin (i.e., when one has insulin resistance), blood glucose levels rise. This gives rise to the diabetic condition.

Risk factors for developing gestational diabetes in pregnant women include:

  • Women with history of gestational diabetes are at an increased risk of developing the condition during future pregnancies. The risk of gestational diabetes recurring during a second pregnancy is between 30- 84%.
  • Women who have given birth to a baby weighing more than 4000 grams are more likely to develop gestational diabetes in their next pregnancy.
  • Women diagnosed with impaired glucose tolerance or impaired fasting glucose levels or pre-diabetes before getting pregnant are at a greater risk of developing gestational diabetes.
  • When women who are overweight/obese get pregnant, they are at a greater risk of developing gestational diabetes. Being overweight increases the risk of gestational diabetes 2-fold, while obesity increases the risk 4-fold and severe obesity 8.6-fold.
  • Women who have a first degree relative (such as a sibling or parent) with diabetes, are at a higher risk of gestational diabetes.
  • Some studies have shown that being aged above 35 years when getting pregnant for the first time increases the risk of gestational diabetes compared with being pregnant at a younger age.
  • Women from certain ethnicities are at an increased risk. Examples include African-Americans, Native Americans, Afro-Caribbeans, Pacific Islanders, Hispanics, Middle eastern and South east Asians.
  • Other risk factors include smoking in the mother and women with polycystic ovarian syndrome (PCOS).

Symptoms of gestational diabetes include:

  • Excessive thirst with dry mouth.
  • Frequent urination.
  • Recurrent infections including thrush or yeast infection.
  • Blurred vision.

How does gestational diabetes affect the baby?

Gestational diabetes raises the risk of birth complications and future health conditions. They include:

  • Premature birth.
  • Macrosomia/ large baby.
  • Placental abruption, which can be fatal to both mother and baby.
  • Trauma during delivery.
  • Stillbirth of the baby.
  • Low blood sugar (hypoglycemia) of the newborn.
  • Development of obesity and diabetes later in the baby’s life.

How does gestational diabetes affect the mother?

  • They have a greater chance of needing a Cesarean birth (C-section), in part due to large infant size.
  • Gestational diabetes may increase the risk of preeclampsia, a maternal condition characterized by high blood pressure and protein levels in the urine.
  • Women with GDM are also at increased risk of having type 2 diabetes after the pregnancy.

What are the screening guidelines for gestational diabetes?

All pregnant women should be screened for gestational diabetes during their pregnancy. Most pregnant women are tested between the 24th and 28th weeks of pregnancy.


Gestational diabetes can be diagnosed by routine blood sugar testing.

The tests used to check for diabetes include:

  1. Fasting blood glucose, which measures the blood sugar around 8 hours after the last meal;
  2. Post prandial blood glucose, which measures blood sugar 2 hours after a meal;
  3. Glycated haemoglobin (HbA1c), which helps determine blood glucose control over the previous three months.

Treatment and control:

Gestational diabetes can usually be controlled by managing the diet and taking regular exercise. However, some women may require medications such as insulin or oral hypoglycemic agents to bring their blood sugar level under control.

It is important to detect and diagnose gestational diabetes carefully so as to avoid any further complications to both, the mother and the child.

Article Credits – Dr. Garima Mishra