A 34-year old pregnant woman (para 1, gravida 2) presented for routine antenatal care at 24 weeks gestation. Her pregnancy was uneventful so far, but she reported tiredness and increased thirst. She was overweight (BMI 28 prior to pregnancy). The patient's past obstetric history included the spontaneous vaginal delivery of a 4.5 kg male infant at 40 weeks gestation, five years before. Her family history revealed her mother had type 2 diabetes mellitus. On examination, vital signs were within normal limits. Uterine size was appropriate for gestational age.