Trends in the Prevalence of Hepatitis C Infection During Pregnancy and Maternal-Infant Outcomes in the US, 1998 to 2018

IMPORTANCE: Injection drug use is the primary risk factor for hepatitis C virus (HCV) infection in adults. More than one-third of newly reported HCV cases occur in women, particularly among persons aged 20 to 39 years. However, nationally representative data on HCV during pregnancy are limited. OBJECTIVE: To estimate the temporal trend of HCV-positive pregnancies during the opioid epidemic and identify HCV-associated maternal and perinatal outcomes. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional study was performed with data from the US, from calendar year 1998 through 2018. Data analysis was conducted from November 14, 2021, to May 14, 2023. Participants included women during in-hospital childbirth or spontaneous abortion in the National Inpatient Sample of the Healthcare Cost and Utilization Project. EXPOSURE: Maternal HCV infection. MAIN OUTCOMES AND MEASURES: The main outcome was the temporal trend, measured as change in the annual prevalence, in the prevalence of HCV positivity among pregnant women since the start of the opioid epidemic in the late 1990s. Secondary outcomes were the associations shown as relative odds between maternal HCV infection and maternal and perinatal adverse events. RESULTS: During the study period, more than 70 million hospital admissions resulted in childbirth or spontaneous abortion. Among them, 137 259 (0.20%; 95% CI, 0.19%-0.21%) involved mothers with HCV; these individuals were more often White (77.4%; 95% CI, 76.1%-78.6%), low-income (40.0%; 95% CI, 38.6%-41.5%), and likely to have histories of tobacco (41.7%; 95% CI, 40.6%-42.9%), alcohol (1.8%; 95% CI, 1.6%-2.0%), and opioid (28.9%; 95% CI, 27.3%-30.6%) use compared with HCV-negative mothers. The median age of women with HCV was 28.0 (IQR, 24.3-32.2) years, and the median age of HCV-negative women was 27.2 (IQR, 22.7-31.8) years. The prevalence of HCV-positive pregnancies increased 16-fold during the study period, reaching 5.3 (95% CI, 4.9-5.7) cases per 1000 pregnancies in 2018. Age-specific prevalence increases ranged from 3-fold (age, 41-50 years) to 31-fold (age, 21-30 years). Higher odds of cesarean delivery, preterm labor, poor fetal growth, or fetal distress were associated with HCV-positivity during pregnancy. However, no significant differences were observed in gestational diabetes, preeclampsia, eclampsia, or stillbirths. CONCLUSIONS AND RELEVANCE: In this cross-sectional study, the prevalence of HCV-positive pregnancies increased markedly, and maternal HCV infection was associated with increased risks for adverse perinatal outcomes. These data may support recent recommendations for universal HCV screening with each pregnancy.