Gestational Diabetes: Causes And Risk Factors

What Causes Gestational Diabetes?

The hormones produced by the placenta in pregnancy—including estrogen, cortisol, and human placental lactogen (HPL)—are what trigger the insulin resistance in women predisposed to the condition known as gestational diabetes. As pregnancy progresses and the placenta grows larger, hormone production also increases and so does the level of insulin resistance. This process usually starts between 20 and 24 weeks of pregnancy. At birth, when the placenta is delivered, the hormone production stops and so does the condition, as this is what causes gestational diabetes.

Risk factors for developing gestational diabetes include:

• Being of African American, American Indian/Alaskan Native, Asian American, Pacific Islander or Latino descent
• Being an overweight or obese woman (i.e., BMI of 25 or higher)
• Having a first degree family history of type 2 diabetes, prediabetes or a previous history of gestational diabetes
• Being older than 25
  
• Having a still birth or a large baby (i.e., 9 pounds or more) in a previous pregnancy
• presence of glycosuria (detection of glucose in the urine despite nomal blood sugar level)
  
• diagnosis of PCOS (PolysCystic Ovarian Syndrome)¹
  

If you have 2 or more of these risk factors you are at HIGH RISK for gestational diabetes.

If you have ONLY ONE of these risk factors you are at AVERAGE RISK for gestational diabetes.

If you have none of these risk factors you are at LOW RISK for gestational diabetes.

SOURCE:

1 - American Diabetes Association. ADA Standards of Medical Care in Diabetes—2008. Diabetes Care, Volume 31, Supplement 1, January 2008. (PDF accessed 2/19/08).

Excerpted from NIH Pub. No. 00-4818.

Reviewed by Francine Kaufman, MD. 4/08