Association between History of Pregnancy and Liver Fibrosis Using Fibrosis-4 Index in Korean Postmenopausal Women: A Nationwide Population-Based Study

BACKGROUND: The association between a history of pregnancy and liver fibrosis remains unclear. Herein, we investigated the association between reproductive factors, including a history of pregnancy and liver fibrosis, in postmenopausal Korean women. METHODS: This study used nationally representative, population-based data collected from the Korea National Health and Nutrition Examination Survey 2008–2017. Of 14,624 women with natural menopause, 11,085 with no previous history of any type of cancer, hepatitis, or chronic heavy alcohol consumption were enrolled. We investigated the reproductive factors, including a history of pregnancy, total reproductive years, age at menarche and menopause, and oral contraceptive use. Liver fibrosis was defined as a Fibrosis-4 index score ≥2.67 kg/m(2). RESULTS: Of the study participants, 372 (3.3%) had advanced liver fibrosis. Multivariable logistic regression analysis showed that women with a history of more than one pregnancy were associated with a lower risk of liver fibrosis compared to women who had never been pregnant, after adjusting for potential confounders (adjusted odds ratio, 0.30; 95% confidence interval, 0.15–0.59). The risk of liver fibrosis did not increase significantly with an increasing number of pregnancies (P for trend=0.135). Other reproductive factors, including total reproductive years, age at menopause and menarche, and oral contraceptive use, were not significantly associated with liver fibrosis. CONCLUSION: Postmenopausal women who had experienced one or more pregnancies had a reduced risk of liver fibrosis. Our findings reveal a potential protective role of pregnancy against liver fibrosis.