Objective: To evaluate the association between maternal acute fatty liver of pregnancy (AFLP) and fetal fatty acid oxidation (FAO) disorders and to define the clinical and genetic characteristics of mothers with AFLP and their fetuses affected by FAO disorders, we performed a systematic literature review of all reported cases of AFLP that underwent genetic testing for FAO disorders.
Data sources: We searched PubMed, Ovid MEDLINE, Cochrane Library, CINAHL (EBSCO), Scopus, and ClinicalTrials.gov. Terms included were related to AFLP and FAO testing.
Methods of study selection: We conducted a systematic literature review from inception through May 18, 2025, to evaluate the relationship between AFLP and fetal FAO disorders. Studies were eligible for inclusion if they evaluated the relationship between AFLP and fetal FAO disorders and provided both detailed pregnancy characteristics for AFLP and the workup of maternal and/or fetal FAO disorder.
Tabulation integration and results: Twenty-seven studies with 77 AFLP cases that underwent genetic or biochemical testing for maternal or fetal FAO disorders were included. Of these 77 pregnancies, 27 (35.1%) were associated with confirmed fetal FAO disorders. The 27 neonates with FAO disorders included 22 fetuses (81.5%) with LCHAD deficiency, three (11.1%) with medium-chain acyl-CoA dehydrogenase deficiency, one (3.7%) with short-chain acyl-CoA dehydrogenase deficiency, and one (3.7%) with carnitine palmitoyl transferase-I deficiency. Stillbirth and infant mortality was reported in 14 of 22 cases (63.6%) with LCHAD deficiency, and there were no recorded fetal or neonatal deaths with other FAO disorders or those with negative genetic testing. One maternal death was reported in a pregnancy with negative genetic testing for FAO disorders and one patient in a coma at the time of publication with an LCHAD-deficient pregnancy. Presentation of AFLP with gastrointestinal manifestations occurred in 87.8% of patients.
Conclusion: Acute fatty liver of pregnancy is associated with fetal FAO disorders in about a third of cases, with the most common FAO disorder being LCHAD deficiency. Both AFLP and LCHAD deficiency are associated with high morbidity and mortality in mothers and neonates. Evaluation for fetal and maternal LCHAD deficiency should be part of the diagnostic evaluation in AFLP.
Systematic review registration: PROSPERO, CRD42021247166.
© 2026 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the American College of Obstetricians & Gynecologists.