Introduction: Regardless of the level of hyperglycemia, gestational diabetes mellitus (GDM) is defined as any grade of glucose intolerance that is identified during pregnancy. Hyperglycemia is a factor that influences the short- and long-term hazards to mothers and babies. Background: To assess the correlation of pregnancy-associated plasma protein A (PAPP-A) with gestational diabetes mellitus and its usefulness in predicting gestational diabetes mellitus at 11–14th week of pregnancy in Egypt. Material & Methods: This was a prospective, observational cohort study with 80 pregnant participants. PAPP-A levels were assessed between 11 and 14 gestational weeks. Screening for GDM using 75-g oral glucose tolerance test following 8-hour overnight fasting, with plasma glucose assessment in fasting and 2 hours at 24-28 weeks of gestation. Results: After Screening for GDM at 24-28 weeks of gestation, the gestational diabetes mellitus (GDM) group ( n = 34 ) and those without GDM group ( n = 46 ). There was variance between the groups concerning fasting blood glucose and postprandial blood glucose levels, both of which were elevated in the gestational diabetes mellitus group. There was variation between both groups with respect to PAPP-A, which was reduced in the gestational diabetes mellitus group, and substantial variance between both groups regarding family history of diabetes, which increased in the gestational diabetes mellitus group. Conclusion: PAPP-A could be used as an early gestational diabetes mellitus screening procedure at 11–14th week of pregnancy.