In Reply

We thank you for your interest in our work.¹ We agree that the population we tested may not represent a high-risk group, and that inclusion of the risk factors you mention would have likely increased the prevalence of hepatitis C virus (HCV) in the sampled population. However, the main issue is which population is more representative of the overall U.S. population risk factors. It is interesting that in a critique suggesting that the population in the Maternal-Fetal Medicine Units may be biased, the reference provided was performed in a single hospital that specifically serves the American Indian and Alaska Native population², a study clearly not representative of the U.S. population as a whole. The fact that we are discussing which population or study result is more representative and the wide variation in prevalence reported in the literature actually argues for an individualized approach rather than a universal one.

Our study was not undertaken to evaluate screening strategies, rather the outcome of interest was mother-to-child transmission of HCV. In the process of identifying a U.S. cohort of HCV-positive pregnant women to evaluate mother-to-child transmission, we amassed screening data on over 106,000 women. This represents the largest and most contemporary cohort of U.S. women evaluated for HCV. We felt compelled to share what we had learned during our years of unselected screening, most notably a low prevalence of women with chronic HCV.

The appropriate strategy for identification of women at risk for mother-to-child transmission of HCV remains unclear, and our findings challenge some recommendations from the Centers for Disease Control and Prevention³, American Association for the Study of Liver Diseases ⁴, and now U.S. Preventive Services Task Force.⁵ We offer alternative strategies to identify these women: screening at the time of delivery or postpartum when access to intervention is not limited by the pregnant state, or preferably at preconception so that treatment could be undertaken prior to pregnancy. Strategies targeting pregnant women are likely predicated on the woman’s engagement in the health care system, not necessarily her medical benefit, representing a bigger public health problem than can be addressed herein. We remain hesitant to endorse universal screening during pregnancy without clear evidence that this strategy results in more benefit than harm for pregnant women. The findings of our study demonstrate that majority of patients screened would derive no benefit from this testing.