Gestational diabetes diagnoses are by blood-glucose testing using random blood-glucose test, screening glucose tolerance test, and fasting blood glucose test.
Gestational Diabetes Test
Early diagnosis of gestational diabetes allows taking proper treatment to prevent/minimize the ill effects of high blood sugar on the mother & child in the short term & long term.
Pregnancy insulin resistance may be due to a combination of increased maternal adiposity and the insulin-desensitizing effects of hormones made by the placenta.
Recent studies show diagnosis and proper gestational diabetes treatment have beneficial effects on maternal and neonatal outcomes, including reduced rates of shoulder dystocia, fractures, nerve palsies, and neonatal hypoglycemia.
Gestational diabetes is defined as any degree of glucose intolerance with onset or first recognition during pregnancy.
Gestational diabetes treatment consists of glucose monitoring, dietary changes, exercise, and pharmacotherapy (if necessary) to maintain the blood glucose level. Insulin therapy is a conventional treatment, although glyburide and metformin may also widely used.
When and how do you go for a gestational diabetes diagnosis?
Timely diagnosis of gestational diabetes can help prevent short-term and long-term ill effects of gestational diabetes.
The American & Canadian guidelines recommend 2 step screening. It includes testing with 50g one hour plasma glucose test. If it is more than 140 mg/dL is considered as positive. The screen-positive women are subjected to 100gm OGTT if 2 or the more abnormal result of plasma glucose confirms gestational diabetes.
The WHO recommends screening for gestational diabetes from 24 to 28 weeks of gestation. The screening test using the 75gm of sweet drink and 2 hour plasma glucose test. If it is more than 140 mg/dL and fasting, more than 126mg/dL is screen positive.
It is advisable to screen all pregnant women at 12 to 16 weeks of gestation. If the results are normal, the next screening is done at 24 to 28 weeks of gestation and finally at 32 to 34 weeks.
In 2010, the International Association of Diabetes and Pregnancy Groups (IADPSG) proposed criteria based on the incidence of adverse perinatal outcomes, as assessed in the Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study. According to these criteria, the diagnosis of gestational diabetes based on at least one value of plasma glucose concentration is equal to or exceeds the thresholds of 92, 180 and 153 mg/dl (for fasting, one-hour and 2-hour post-glucose load glucose values respectively), after performing a 75 g OGTT. Diabetes Care. 2010 Mar; 33(3):676-82.
HAPO study results that demonstrated a continuous association of maternal glycemia with adverse pregnancy outcomes. IADPSG criteria developed based on the HAPO study. The IADPSG consensus panel consisted of leading experts in the field of gestational diabetes from a variety of countries.
The IADPSG suggests screening in all women at the first prenatal visit and a 75 g OGTT between the 24th and 28th week of gestation. One or more abnormal value confirm the diagnosis of gestational diabetes; more than or equal to 92, 180, or 153 mg/dl for fasting, 1-hour and 2-hour plasma glucose, respectively.