Lactation ketoacidosis is a rarely described form of elevated anion gap metabolic acidosis precipitated by the large glucose requirement incurred during lactation. When available body glucose stores are inadequate to meet the energy requirements of metabolism whilst lactating (such as in low carbohydrate diets), water soluble ketone bodies are derived from fat stores to be utilised as fuel. This occurs in a low-insulin, high-glucagon environment, where lipoprotein lipase stimulates hepatocyte mitochondrial conversion of fatty acids to acetyl-coA, to enter the ketogenic pathway and form acetoacetate, beta-hydroxybutyrate and acetone.
We describe a case of a woman, 5 months post-partum and breastfeeding twins, following a ketogenic very low carbohydrate diet designed to regain her pre-pregnancy weight, who presented unwell, with a pH of 7.065, bicarbonate 6.8mmol/L, serum ketones 7.1mmol/L, and an anion gap of 25mmol/L. Lactate was 1.04mmol/L. Diabetic and alcoholic ketoacidosis were excluded, as was ingestion of salicylate and other organic acids. A dietary history revealed a very-low carbohydrate, hypocaloric diet of approximately 35g of carbohydrate, and 1000 calories daily. The diagnosis of lactation ketoacidosis was made. Management included intravenous dextrose and adequate caloric intake, and her biochemistry normalised within 48 hours. Dietician review and education formed the cornerstone of her admission.
There are only 5 cases of lactation ketoacidosis described in the literature, and of these, 2 occurred secondary to very low carbohydrate diets designed to promoted ketosis and weight loss. With the increasing popularity of ketogenic diets to regain pre-pregnancy weight, women who are breastfeeding should be educated about this concerning complication during lactation. Adequate caloric intake to support lactation should be encouraged.