Gestational diabetes mellitus (GDM) is defined as glucose intolerance that begins or is first recognized during pregnancy. Numerous clinical factors are associated with an increased likelihood of GDM, such as increasing age, obesity, ethnicity, family history of diabetes and past obstetric history. There is a well-documented relationship between maternal hyperglycemia and increased rate of macrosomia, cesarean section, stillbirth, fetal congenital malformations, shoulder dystocia, hypoglycemia, hyperbilirubinemia, pre-eclampsia, preterm delivery, childhood obesity, and increased risk of maternal development of type 2 DM later on in her life. This case-based review is designed to provide health care workers a framework on using various ultrasound imaging modalities in early detection of the effects of gestational diabetes, and the specific conditions and/or anomalies seen in diabetic pregnancies.