Background: Abnormal liver function tests are common in pregnancy; however, liver failure is rare. Pregnancy is a catabolic state that can precipitate illness in patients with underlying metabolic disorders.
Case: A 19-year-old woman presented at 14 weeks of gestation with an alanine transaminase of 2,252 international units/L (less than 30), an international normalized ratio of 6.9 (0.9-1.2), and an ammonia of 58 micromole/L (11-51 micromole/L). No cause was identified on routine investigations including liver biopsy. Biochemical and clinical deterioration prompted investigation for a metabolic disorder. Urinary orotic acid was elevated, consistent with the urea cycle disorder type 1 citrullinemia. Appropriate management (arginine supplementation and dietary protein restriction) led to rapid improvement and later delivery of a healthy neonate.
Conclusion: This is an unusual presentation that reminds us of the importance of considering metabolic disorders during the catabolic stress of pregnancy.