Pregnancy Outcomes in Women With Autoimmune Hepatitis - A Nationwide Population-based Cohort Study With Histopathology

BACKGROUND & AIMS: Autoimmune hepatitis (AIH) is a chronic inflammatory liver condition that predominantly affects women. However, pregnancy risks remain unclear. METHODS: A nationwide population-based cohort study (ESPRESSO) in Sweden from 1992 to 2016 including 309 singleton births in women with AIH and 1532 matched births in women from the general population was performed. AIH was diagnosed as a combination of administrative coding from medical diagnosis of AIH and liver biopsy data from Sweden's 28 pathology departments. Using conditional logistic regression, odds ratios (ORs) for adverse pregnancy outcomes were determined. RESULTS: Among 306 live births to women with AIH, 51 (16.7%) were preterm, compared with 70 of 1524 (4.6%) reference births. This corresponded to an OR of 5.10 for preterm birth (95% confidence interval [CI], 3.29-7.92), with similar odds using sibling comparators. Women with AIH with and without cirrhosis had similar odds for preterm birth. The AIH association was particularly strong with medically indicated preterm birth (OR, 13.01; 95% CI, 5.50-30.79). AIH was associated with low birth weight (OR, 5.31; 95% CI, 2.82-9.99) and low 5-minute Apgar score (OR, 3.46; 95% CI, 1.14-10.49) offspring, but we found no association with congenital malformations (OR, 1.14; 95% CI, 0.68-1.91), small for gestational age (OR, 1.04; 95% CI, 0.38-2.85), stillbirth (OR, 0.59; 95% CI, 0.02-18.88), or neonatal death (OR, 7.42; 95% CI, 0.65-84.25). Maternal AIH was linked to an increased odds of cesarean section (OR, 1.44; 95% CI, 1.04-2.00) and preeclampsia (OR, 3.65; 95% CI, 2.01-6.64), but not to gestational diabetes. CONCLUSIONS: Maternal AIH was associated with a 5-fold higher odds of preterm birth, and cirrhosis at diagnosis did not add to the impact of AIH on preterm birth. Future studies are needed to understand how to reduce this risk.