<prompt> Gestational diabetes mellitus GDM has been traditionally defined as any degree of glucose intolerance with onset or first recognition during pregnancy. Regarding diabetes in pregnancy all are true, EXCEPT:Glucose challenge test is done between 24-28 week50 gm of sugar given as screening testInsulin resistance improves with pregnancyDiabetes control before conception is impoant to prevent malformation  <response>: The hallmark of gestational diabetes mellitus GDM is insulin resistance. Women with GDM exhibit more insulin resistance than normal patients, which is a function of their pre pregnancy metabolic state. Screening test consists of a 1-hour 50-g oral glucose challenge test GCT, which is administered between 24 and 28 weeks of gestation. Diabetes control before conception is impoant to prevent malformation. Ref: Murphy A., Janzen C., Strehlow S.L., Greenspoon J.S., Palmer S.M. 2013. Chapter 31. Diabetes Mellitus Pregnancy. In A.H. DeCherney, L. Nathan, N. Laufer, A.S. Roman Eds, CURRENT Diagnosis Treatment: Obstetrics Gynecology, 11e. 