What Is Gestational Diabetes?
You may have a greater risk of developing gestational diabetes if you:
- Are obese when you become pregnant
- Have high blood pressure or other medical complications
- Have given birth to a large (greater than 9 pounds) baby before
- Have given birth to a baby that was stillborn or suffering from certain birth defects
- Have had gestational diabetes in previous pregnancies
- Have a family history of diabetes
- Come from certain ethnic backgrounds, including African, Hispanic, Asian, Native American, or Pacific Islander
- Are older than 30
But half of women who develop gestational diabetes have no risk factors.
If left untreated, gestational diabetes can cause serious complications for your newborn. For example, babies of untreated mothers with gestational diabetes may grow too large (called macrosomia), increasing the risk of problems during delivery, such as injuries to the baby's shoulders and arms and nerves in these areas. Having a very large baby may also increase your risk for requiring a cesarean section or other assistance during delivery (such as a forceps or vacuum delivery). Your baby may also experience a sudden drop in blood sugar after birth, requiring treatment with a sugar solution given through a needle in the vein. Your newborn baby may also have a higher risk of developing jaundice (a condition that causes yellowing of the skin and whites of the eyes) and breathing problems.
The risk of birth defects in infants whose mothers have gestational diabetes is very low because most pregnant women develop gestational diabetes after the 20th week of pregnancy, when the fetus has already fully developed. The risk of birth defects increases only if you had undiagnosed diabetes before pregnancy or if you have high, out-of-control blood sugar levels during the first six to eight weeks of pregnancy.
If you have gestational diabetes, your baby doesn't have an increased risk of developing type 1 diabetes during childhood. However, your child is more likely to develop type 2 diabetes later in life as well as be overweight throughout life.
Most women's blood sugar levels return to normal after delivery. However, once you've had gestational diabetes, you are more likely to develop gestational diabetes again during subsequent pregnancies. You also have an increased risk of developing diabetes later in life. Women with gestational diabetes have a 50% chance of developing diabetes within 10 to 20 years of delivery.
What Causes Gestational Diabetes?
Gestational diabetes is the result of changes that occur in all women during pregnancy. Increased levels of certain hormones (including cortisol, estrogen, and human placental lactogen) can interfere with your body's ability to manage blood sugar. This condition is called "insulin resistance." Usually your pancreas (the organ that produces insulin) is able to compensate for insulin resistance by increasing insulin production (to about three times the normal amount). If your pancreas cannot sufficiently increase insulin production to overcome the effect of the increased hormones, your blood sugar levels will rise and cause gestational diabetes.