GESTATIONAL DIABETES: INTRODUCTION AND SCREENING

It is the glucose intolerance present in pregnancy. Child born of mother with gestational diabetes will develop malformations. American Diabetes Association recommendations for screening GDM;

Subjects should have OGTT if they fulfill one of the following:

·         FPG ≥126 mg/dl at any stage of gestation

·         RBS ≥200 mg/dl at any stage of gestation

·         Marked obesity

·         History of GDM

·         Glycosuria

·         Strong family history

·         Positive screening

Screening procedure:

·         Plasma glucose measurement:

·         50g oral glucose load administered between 24^th and 28^th week of gestation (3^rd trimester) without regard of time of day or meal, to all pregnant women who have not been identified as having glucose intolerance by the 24^th week.

·         Plasma glucose 60 min later a value ≥140 mg/dl indicates need for full diagnostic glucose tolerance test.

Diagnostic OGTT:

75g or 100g glucose load administered in morning after overnight fasting for at least 8 h and after at least 3 days of unrestricted diet and physical activity

Venous plasma glucose measured fasting and at 1 hr, 2 hr and 3 hr after glucose load (upto 2 hr if 75 g is given)

Two or more of the following venous plasma concentrations must be met or exceeded for positive diagnosis

·         Fasting, ≥95 mg/dl

·         1 hr, ≥180 mg/dl

·         2 hr, ≥155 mg/dl

·         3 hr, ≥140 mg/dl

Pregnant women who fulfill all the following criteria need not be screened for GDM:

·         <25 years of age

·         Normal body weight

·         No familial history of diabetes or abnormal glucose metabolism

·         No history of poor obstetric outcome

·         Not member of an ethic/racial group with a high prevalence of diabetes.

Gestational diabetes or delivery of a large or macrosomic baby is strongly predictive of type 2 diabetes and many recommend screening such women for type 2 diabetes mellitus by OGTT six weeks after delivery, and periodically (every 1-2 years) either by using OGTT or measuring FPG.

Although asymptomatic and non life threatening to mother GDM is associated with increased incidence of neonatal mortality and morbidity, including hypocalcemia, hypoglycemia and macrosomia. The maternal hyperglycemia causes the fetus to secrete more insulin, resulting in stimulation of fetal growth and macrosomia. So, when a child is born this high amount of insulin causes hypoglycemia in child.