(B-271) Adverse Pregnancy and Birth Outcomes in Women with Biopsy-Proven MASLD: A Nationwide Cohort Study

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) is highly prevalent and associated with an increased risk of adverse pregnancy and birth outcomes.

Objectives: We aimed to assess the risk of adverse pregnancy and birth outcomes among women with MASLD with particular focus on the roles of obesity, familial factors, and disease severity.

Methods: We performed a nationwide cohort study in Sweden (1992-2017) including 240 births to 162 women with biopsy-confirmed MASLD and 1,140 reference births to 1,138 women without known MASLD, matched by maternal age at delivery, calendar year of delivery, and parity. We used multivariable conditional logistic regression to determine adjusted odds ratios (ORs) with 95% confidence intervals (CI) for adverse pregnancy and birth outcomes. We assessed the outcomes by histological subgroup of MASLD (i.e., disease severity), body mass index strata (to address the role of obesity), and additionally performed a sibling-controlled analysis comparing outcomes to sisters of women with MASLD.

Results: Preterm birth occurred in 40 (16.7%) pregnancies of women with MASLD compared to 53 (4.7%) in reference births, yielding an adjusted OR of 3.41 (95% CI 1.98-5.88). The increased risk was unchanged when compared with reference women with overweight or obesity (OR 4.60, 95% CI 2.00-10.60). The association was seen in medically indicated preterm birth (OR 11.90, 95% CI 2.46-57.59), as well as spontaneous preterm birth (OR 2.42, 95% CI 1.16-5.04). Maternal MASLD was also linked to increased odds of cesarean section (OR 1.63, 95% CI 1.17-2.27), which was driven by emergency cesarean section (OR 1.90, 95% CI 1.20-3.02). However, the association with cesarean section vanished when compared with overweight or obese women without MASLD (OR 1.20, 95% CI 0.77-1.86). We found no association for instrumental delivery (OR 0.84, 95% CI 0.45-1.59), induction of labor (OR 1.27, 95% CI 0.87-1.85), small for gestational age (OR 1.52, 95% CI 0.94-2.43), large for gestational age (OR 1.17, 95% CI 0.78-1.74), low birth weight in term deliveries (OR 1.25, 95% CI 0.28-5.48), or congenital malformations (OR 1.06, 95% CI 0.57-2.00). Absolute numbers of neonatal deaths and stillbirths were low and comparable in both groups. Main results were confirmed in sibling analyses and did not increase with MASLD severity.

Conclusions: MASLD is a risk factor for preterm birth, which was independent of the degree of obesity and familial factors. Increased cesarean section risks are potentially due to obesity, while stillbirths, neonatal deaths, and congenital malformations were rare. We did not find more adverse outcomes with increasing MASLD severity; however, statistical power was limited.