Introduction: Diabetic ketoacidosis (DKA) in pregnancy could be a disastrous event, which increased both maternal and perinatal morbidity and mortality. As opposed to the typical findings of hyperglycemia, DKA can occur with a relatively low, or even normal blood glucose level, which is called euglycemic DKA. It particularly affects pregnant woman with pre-existing diabetes mellitus and poor oral intake.

Methodology: We report a case of euglycemic DKA in a pregnant woman with gestational diabetes mellitus on insulin.

Results: A 34 years old woman at 35 weeks of gestation, with underlying gestational diabetes mellitus, presented with 4 days history of vomiting and poor oral intake. She omitted insulin injection for 3 days duration. Apart from moderately dehydrated and tachycardic (pulse rate 136 beats/min), her systemic examination was unremarkable. Blood glucose level was 9.4 mmol/L with ketonuria of 2+. Venous blood gas revealed pH 7.19, bicarbonate 10.4 mmo/L and anion gap of 9.6 mmo/L. She was admitted to ICU after a late revised diagnosis of euglycemic DKA made by the endocrine team. An emergency caesarean section was performed for fetal distress on the same day. There was improvement in the metabolic acidosis with intravenous fluid and insulin infusion. Both the patient and her baby were discharged well after 5 days. Six weeks later, she was diagnosed to have type 2 diabetes mellitus following an abnormal modified glucose tolerance test.

Conclusion: This case illustrates the diagnostic challenge of DKA when euglycemia was encountered. This rare condition necessitates high index of suspicion by clinician with early recognition and prompt treatment, in order to prevent further maternal and fetal adverse outcomes.                                                   

Keywords: Euglycemic diabetic ketoacidosis, gestational diabetes mellitus