1 step approach-WHO & IAD PSG
→ It is done only in females with any risk factor @ 24-28 weeks of pregnancy.
→ It is used both for screening and diagnostic purpose.
→ Patient is advised unrestricted diet for 72 hours followed by overnight fasting and then 75 gm of glucose is given.
→ Total 3 samples are taken:
→ 1st sample – fasting sample
→ 2nd sample = After 1 hour of 75 gm of glucose
→ 3rd sample = After 2 hours of 75 gm glucose
→ Reference Readings of one step approach
|Time||75 g OGTT|
|1 hour||180 mg/dl|
|2 hours||153 mg/dl|
→ Out of these 3 values if any I value is abnormal; patient is considered as having gestational diabetes\