Sometimes diabetes develops during pregnancy in women without diabetes, this condition is called gestational diabetes mellitus (GDM). Gestational diabetes may occur in 3-10 % of all pregnancies. As a result of gestational diabetes blood sugar (glucose) level increases, this range varies person to person.
Gestational diabetes is not caused by decreased insulin hormone level, it is caused by the hormones which are produced during pregnancy to support and develop the baby. These pregnancy hormones block the insulin effect in mother’s body, this is called insulin resistance. Insulin hormone can’t affect properly because of this pregnancy hormone effect and can’t reduce blood sugar level as expected. As a result, pregnant develops intolerance to carbohydrates and blood glucose level increases.
Gestational diabetes commonly occurs after 6th month of pregnancy. Most of the pregnant women return to normal after birth but rarely diabetes problem may be permanent. Control can be done with OGTT ( oral glucose tolerance test) with 75 gr glucose, 6 week after the birth.
Cause of gestational diabetes
In first months of pregnancy, some changes occur in pregnant and body produces some hormones like progesterone and estrogen to provide energy for growing baby. Pancreas beta cells produces more insulin by these hormones effect. In later months body produces placental lactogen which is a pregnancy hormone that is similar to growth hormone and cause insulin resistance.
Gestational diabetes mellitus (GDM) does not occur in pregnants who have normal pancreatic functions and produce enough insulin against pregnancy hormones. Sometimes pregnant’s pancreas functions may not be sufficient to produce enough insulin and gestational diabetes occurs.
Diagnosis of gestational diabetes
Some kind of laboratory tests are used to diagnose gestational diabetes;
- Blood sugar level measurement
- Urine glucose test
- Glucose tolerance test between 24-28 weeks of pregnancy
Oral glucose tolerance test normal results
Normal results are expected as listed below to say that you don’t have gestational diabetes, you’ll be diagnosed for gestational diabetes at least 2 of these results are found abnormal
- Fasting blood sample: Less than 95 mg/dL
- 1st hour blood sample: Less than 180 mg/dL
- 2nd hour blood sample: Less than 155 mg/dL
- 3rd hour blood sample: Less than 140 mg/dL