Abstract
BACKGROUND: Pregnancies affected by metabolic dysfunction-associated steatotic liver disease (MASLD) have tripled over the past decade. However, tools to assess MASLD in pregnancy are limited to ultrasound, which has shown poor reproducibility and does not provide quantitative data. Current guidelines for non-pregnant adults recommend the use of vibration-controlled transient elastography (VCTE) with controlled attenuation parameter (CAP) for staging and monitoring of liver disease. Given the limitations of ultrasound and the scarcity of data on use of VCTE in pregnancy, we evaluated the use of VCTE to determine the prevalence of MASLD in a pregnant population. Also, we determined the association between increased VCTE-derived CAP scores and adverse pregnancy outcomes. METHODS: Pregnant individuals with no history of liver disease presenting for routine prenatal care were followed up throughout pregnancy and had VCTE-derived CAP assessments at 24-32 weeks of gestation. Postpartum VCTE-derived CAP assessments were also obtained. Multivariable logistic regression was performed to evaluate for predictors of liver steatosis (CAP) and liver stiffness (liver stiffness measurement [LSM]) and association with adverse pregnancy outcomes. FINDINGS: 247 pregnant individuals (mean age 30·0 years [SD 6·0]; mean pre-pregnancy BMI 30 kg/m² [SD 6·1]) had VCTE assessments during pregnancy. The prevalence of MASLD was 11% (95% CI 7-15%) based on VCTE-derived CAP and evidence of cardiometabolic disease. On multivariable analyses, pre-pregnancy BMI was a predictor of increased CAP scores (odds ratio [OR] 1·13, 95% CI 1·05-1·22), whereas polycystic ovary syndrome was a predictor of liver stiffness (4·79, 1·11-20·65). Increased CAP scores were associated with the development of intrahepatic cholestasis of pregnancy (OR 12·07, 95% CI 1·97-73·87) and LSM with large for gestational age (8·33, 1·02-67·87). Of those with postpartum follow-up (n=41), 24 (59%) individuals had an increase in postpartum CAP scores by at least 10%. INTERPRETATION: We found a high prevalence of MASLD in pregnancy that might not have otherwise been diagnosed. Pre-pregnancy BMI was the strongest predictor of liver steatosis and polycystic ovary syndrome for liver stiffness. Increased VCTE-derived CAP assessment results were associated with certain adverse pregnancy outcomes; however, this result should be interpreted with caution given the small sample size. VCTE-derived CAP assessment could be a useful non-invasive bedside tool to diagnose and assess liver disease in the obstetric context. The prognostic value of VCTE-derived CAP requires further investigation. FUNDING: National Institutes of Health-The National Heart, Lung, and Blood Institute, and Irma T Hirschl Monique Weill-Caulier Trust.