Maternal risk factors associated with inadequate testing and loss to follow-up in infants with perinatal hepatitis C virus exposure.

Objectives: Inadequate testing (IT) and follow-up in infants with perinatal hepatitis C virus (HCV) exposure are challenging. We sought to identify maternal clinical and demographic risk factors that are associated with inadequate testing (IT) and follow-up of perinatally HCV-exposed infants.
Methods: In a retrospective cohort study spanning a period of 23 years, medical records of HCV-infected women and their perinatally exposed infants were reviewed for maternal characteristics that could be associated with their infants' IT and loss to follow-up.
Results: A total of 27% (108/407) of HCV-exposed infants were adequately tested (AT) for HCV perinatal transmission. Among AT infants, HCV transmission rate was 11% (12/108). History of maternal intravenous drug use (IVDU) was significantly higher in IT vs. AT infants [88% (193/218) vs. 76% (70/92); p = 0.005]. The percentage of mothers on methadone maintenance treatment during pregnancy was higher in AT vs. IT infants [53% (35/66) vs. 34% (65/186); p = 0.010]. The percentage of mothers with HCV medical care was higher among AT than IT infants [54% (56/102) vs. 41% (106/255); p = 0.022].
Conclusions: Infants born to HCV-infected mothers have suboptimal testing, possibly leading to an underestimation of the rate of HCV vertical transmission. Infants of mothers receiving HCV medical care and methadone treatment have improved testing. Infants of HCV-positive mothers with history of IVDU have lower rates of testing. Screening HCV-infected pregnant women for history of IVDU and linking them to drug treatment programs, and HCV medical care may improve testing and follow-up in their infants.