These risk factors include Gestational diabetes or a macrosomic neonate (weight > 4500 g at birth) in a previous pregnancy Unexplained fetal losses A strong family history of diabetes in 1st-degree relatives A history of persistent glucosuria Body mass index (BMI) > 30 kg / m2 Polycystic ovary syndrome with insulin resistance If the 1st-trimester test is normal, the 50-g test should repeated at 24 to 28 weeks, followed, if abnormal, by a 3-hour test.