MASLD in Pregnancy: Rising Prevalence and Adverse Maternal and Perinatal Outcomes in a National Cohort, 2016-2022.

BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD) is rising in parallel with obesity and metabolic syndrome among reproductive-age women. Although MASLD has been associated with adverse pregnancy outcomes, its burden and clinical impact in modern cohorts remain incompletely defined. METHODS: Using 2016-2022 discharge data from the National Inpatient Sample (NIS), we identified hospitalized pregnant women ≥20 weeks gestation. Patients were stratified by the presence of MASLD, other chronic liver diseases (CLD), or no liver disease. Multivariable regression analyses compared maternal and perinatal outcomes while adjusting for demographics, comorbidities, pregnancy-related factors, and hospital characteristics. RESULTS: Among 24,808,697 pregnancy-related hospitalizations, 21,860 (0.09%) involved MASLD, 182,520 (0.74%) other CLD, and 24,604,317 (99.17%) no CLD. MASLD prevalence rose threefold from 45.7 to 141.6 cases per 100,000 pregnancies between 2016 and 2022. Patients with MASLD had a greater cardiometabolic comorbidity burden compared with both comparator groups. After adjustment, MASLD was associated with higher odds of hypertensive complications (other CLD: adjusted odds ratio [aOR] 2.50; no CLD: aOR 1.88; p < 0.001 for both), preterm birth (other CLD: aOR 1.45; no CLD: aOR 1.41; p < 0.001 for both), and large-for-gestational-age infants (other CLD: aOR 1.25, p = 0.024; no CLD: aOR 1.18, p = 0.014). Compared with pregnancies without CLD, MASLD was also associated with postpartum hemorrhage (aOR 1.33, p < 0.001). No differences were observed in fetal growth restriction, cesarean delivery, or fetal death. MASLD was associated with longer hospitalizations and higher charges. CONCLUSION: The prevalence of pregnancy-associated MASLD is increasing and is independently associated with maternal morbidity and greater healthcare utilization.