For Oral GTT –

Prior diet of  > 150 g of carbohydrate daily, x 3 days
no alcohol, and unrestricted activity for 3 days before test.

To come for test in morning after 10 to 12 hours of fasting.
Take a urine sample and Blood sample for FBS.
Loading dose of glucose to  be consumed within 5 minutes: [For adults = 75 g, for children = 1.75 g/kg of but never >75 g), for pregnant women = 100 g.
Draw blood at 30, 60 ,90 &,120 minutes; in fluoride vial ( as for F/PP)
Along with each sample also collect urine sample for urine sugar estimation.
 No medication, smoking, or exercise (remain seated) during test.
Test should  not to be done, during recovery from acute illness, emotional stress, surgery, trauma, inactivity due to chronic illness; therefore is of limited or no value in hospitalized patients.
Certain drugs should be stopped several weeks before the test (e.g., oral diuretics, oral contraceptives, phenytoin).

For GCT ( Glucose challenge test )  -

Advised to Patient come on any time in  day & give 50 gms of glucose in 200 ml water. Advised her to take complete rest . The collect the blood after 1 hrs.

Blood sample will be drawn exactly Two hrs from the starting time of meals or consumption of a 75 gm of glucose (as specified by the physician).If person is not a known diabetic / or on anti diabetic treatment , prefer post glucose estimation.