A Deceptive Recovery: When Falling Glucose Concealed Rising Acidosis in Pregnancy

Introduction Diabetic ketoacidosis (DKA) complicates 5–10% of pregnancies with pregestational diabetes and is associated with an 8-fold increase in severe maternal morbidity and fetal mortality rates of 10–35%. Up to 35% of obstetric DKA cases present with euglycemia (glucose <200 mg/dL), which may lead clinicians to underestimate severity and anchor management decisions to glucose rather than acidosis. Case A 22-year-old G1P0 at 31 weeks 6 days with type 1 diabetes presented with a 4-day history of nausea and vomiting. She had been taking her long-acting insulin but only half of her short-acting doses. Initial labs revealed CO₂ 13 mEq/L, anion gap 19.1, glucose 165 mg/dL, and 4+ urine ketones. No blood gas was obtained. She was admitted to the antepartum unit and managed with home subcutaneous glargine, maintenance IV fluids at 125 mL/hr, and antiemetics. Glucose declined (165 → 46 → 118 mg/dL), requiring glucagon for hypoglycemia. Despite apparent glucose improvement, repeat labs the following day showed worsening acidosis: VBG pH 7.16, CO₂ <10, bicarbonate 6 mEq/L, and beta-hydroxybutyrate 4.59 mmol/L. She was transferred to the ICU for insulin infusion. A urinary tract infection was identified only at that time. Discussion Seven changes in management from ACOG-recommended DKA management were identified: (1) delayed IV insulin infusion initiation, (2) inadequate fluid resuscitation (125 mL/hr vs. recommended 4–6 L/12 hours), (3) absent blood gas at presentation, (4) iatrogenic hypoglycemia from continued long-acting insulin without dextrose-containing fluids, (5) delayed UTI identification, (6) insufficient lab monitoring frequency, and (7) triage to a unit without insulin drip capability. Conclusion Glucose normalization does not indicate DKA resolution. The treatment target is the correction of acidosis and ketosis. This case emphasizes the need for institutional obstetric DKA protocols mandating immediate IV insulin infusion, aggressive fluid resuscitation, serial acid-base monitoring, and clear ICU transfer criteria regardless of glucose level.