(819) Trends and outcomes in deliveries affected by maternal fatty acid oxidation defects

Improved detection and management of fatty acid oxidation defects (FAOD) over time has led to increased survival to reproductive age. National data is needed on the prevalence and obstetric outcomes for this group of patients, given the potential increased risk of complications such as hypoglycemia or rhabdomyolysis related to the metabolic stress of labor and delivery.

Study Design: Deliveries of patients with FAOD were identified using ICD-10CM codes from the 2016-2020 abstracts of the Nationwide Inpatient Sample. Trends in the rates of maternal FAOD delivery hospitalizations were assessed using Joinpoint regression with measured association expressed as annual average percent change (AAPC). Baseline patient demographics, obstetric outcomes, and health care resource utilization were compared using Chi-square or Wilcoxon rank sum where appropriate. Unadjusted logistic regression models were fit comparing risks of obstetric complications in patients with and without FAOD, expressed as odds ratios (OR) and 95% confidence intervals (CI).

Results: 492 births affected by maternal FAOD were identified, with an increasing incidence over time from 20 to 45 cases per million birth hospitalizations (AAPC 24.8%, 95% CI: 11.6%, 42.7%). Deliveries with FAOD were associated with statistically significant  higher mean length of stay (LOS) (3.6 versus 2.7 days) and delivery costs ($8,248 vs. $6,642). Births with FAOD were at higher odds of postpartum hemorrhage (PPH) (OR 1.76, 95% CI: 1.05, 2.95) but were not at higher likelihood of transfusion, non-transfusion severe maternal morbidity, preterm delivery, chorioamnionitis, hypertensive disorders of pregnancy, placental abruption, or cesarean delivery.

Conclusion: The prevalence of deliveries affected by a known maternal FAOD is increasing and associated with increased LOS, costs, and likelihood of PPH, although with no observed increased odds of other birth complications.  These outcomes are helpful when counseling patients with FAOD considering pregnancy. Further research is needed to understand drivers of PPH and increased costs among these patients beyond LOS.