PC2148: Oh Baby! a Case of Lactation Induced Ketoacidosis

Introduction: Anion-gap metabolic acidosis (AGMA) is a common physiologic derangement that internal medicine-pediatrics (Med-Peds) physicians regularly encounter and can occur in patients of all ages. A number of conditions can precipitate AGMAs and various mnemonics are often employed to concisely summarize the more common etiologies. We present a case of breastfeeding-induced starvation ketoacidosis, a rare etiology of AGMA that brings to light the importance of thorough history taking and counseling in ensuring high quality, effective care for patients of all ages. Topics discussed can be applied to all pregnant or breastfeeding patients during both pediatric and adult clinical encounters.

Case Description: A 29-year-old G4P4004 woman presented 4 weeks post-partum to the emergency department for one day of headache, nausea, vomiting, and dyspnea with notable 40lb weight loss since delivery. To add, on further questioning it was discovered that the patient was significantly restricting carbohydrates in her diet in an effort to lose weight. She had been breastfeeding her newborn since delivery with adequate milk production and appropriate infant weight gain.
The patient was tachycardic and tachypneic on presentation. Laboratory evaluation revealed a severe AGMA, with concomitant non-anion gap metabolic acidosis (VBG: 7.02/19/31/5, AG: 30, delta gap 18). Lab work revealed a blood glucose level of 68mg/dL, a lactic acid level of 1.1 mmol/L, and an elevated beta-hydroxybutyrate level of 122.5mg/dL. Other causes of presenting symptoms, for example, sepsis, toxic alcohols, and pulmonary embolism were ruled out and our patient was admitted to the medical intensive care unit for ongoing management. She was resuscitated with intravenous dextrose containing fluid, breastfeeding was paused, and she had subsequent resolution of her acidosis.
Given the significant caloric demands incurred during breastfeeding coupled with the patient’s reported dietary habits and lack of other identifiable precipitants, it was concluded that lactation ketoacidosis was the underlying diagnosis.

Discussion: It is known that breastfeeding causes marked alternations to the maternal metabolism. There is a 15-25% increase in energy expenditure to support lactogenesis. These nutrients are usually mobilized from fat stores or, more typically, obtained from maternal dietary intake. This case highlights that even for experienced mothers, as was the case here, every pregnancy and delivery are unique, and it is important to screen and counsel on maternal mental and physical health. Ensuring adequate nutrition for nursing mothers will, in turn, ensure adequate nutrition and well-being of the neonate.

Conclusion: While lactation ketoacidosis represents an extreme complication for a breastfeeding mother, it nonetheless demonstrates the unique biologic interplay between mother and child. The Med-Peds community has a unique passion to educate and empower patients of all ages. We can truly optimize our potential as Med-Peds physicians by thoughtfully caring for both mother and child in a way that enhances short- and long-term health.