Which of the following histories is not an indication to perform oral glucose tolerance test to diagnose gestational diabetes mellitus?
Previous Eclampsia
Previous Congenital anomalies in the fetus
Previous Unexplained fetal loss
Polyhydramnios
Indications for performing GCT: All those conditions in which there is risk of having diabetes.
On the basis of risk factors females are categorised into 3 category:
Low risk
All of the folowing:

Member of an ethnic group with a low prevalence of GDM
No known diabetes in first degree relatives
Age <25 years
Weight normal before pregnancy
Weight of previous baby normal at birth
No history of abnormal glucose metabolism
No H/o poor obstetrical outcome

Average risk
One or more of the following:

Member of an ethnic group with a high prevalence of GDM
Diabetes in a first degree relative
Age > 25 years
Overweight before pregnancy
Weight high at birth (previous baby)

High risk

Marked obesity
Strong family history of type II DM
Previous history of GDM impaired glucose metabolism or glucosouria
Unexplained stillbirth
H/o previous congenitally malformed baby