Because hepatitis C virus (HCV) infection is typically asymptomatic, its presence can easily be overlooked without appropriate screening efforts. For those screening efforts to be effective, they must keep pace with the changing demographic face of this increasingly prevalent but treatable disease.
Perhaps the most dramatic shift in HCV demographics in recent years has been the increase of infections among those born after 1965, a trend primarily driven by the opioid epidemic. In addition, data from the National Notifiable Diseases Surveillance System show that cases of diagnosed HCV doubled among women of childbearing age from 2006 to 2014, with new infections in younger women surpassing those in older age groups.
With such trends in mind, the Centers for Disease Control and Prevention (CDC) broadened their recommendations regarding HCV in 2020 to include one-time testing in all adults aged ≥ 18 years and screening of all pregnant women during each pregnancy, except where the prevalence of infection is < 0.1%, a threshold that no state has yet achieved.
The US Preventive Services Task Force (USPSTF) subsequently followed suit in their own recommendations.
The American Association for the Study of Liver Diseases (AASLD)/Infectious Diseases Society of America (IDSA) have long advocated for extensive expansion in their screening recommendations for HCV, including pregnancy.
Although the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) did not immediately adopt these recommendations, they have since endorsed them in May 2021 and June 2021, respectively.
The Hepatologist Perspective
As a practicing hepatologist, this seems like an uncontroversial recommendation. Obstetricians already screen for hepatitis B virus in each pregnancy. It should be easy to add HCV testing to the same lab testing.
Risk-based screening has repeatedly been demonstrated to be ineffective. It should be easier to test all women than to ask prying questions about high-risk behaviors.
Given the increase of injection drug use and resultant HCV infections in women of childbearing age, this seems like a perfect opportunity to identify chronically infected women and counsel them on transmission and cure. And pregnancy is also unique in that it is a time of near-universal health coverage.
Let's address some of the operational issues.
The diagnostic cascade for HCV can be made very easy. HCV antibody testing is our standard screening test and, when positive, can automatically reflex to HCV polymerase chain reaction (PCR), the diagnostic test. Thus, with one blood sample, you can both screen for and diagnose infection.
Current guidelines do not recommend treating HCV during pregnancy, although therapy can be considered on an individual basis. Linkage to a knowledgeable provider who can discuss transmission and treatment, as well as assess the stage of liver injury, should decrease the burden on the ob/gyn.
The impact on pregnancy is marginal. HCV should not change either the mode of delivery or the decision to breastfeed. The AASLD/IDSA guidance outlines only four recommendations for monitoring during pregnancy:
Obtain HCV RNA to see whether the infection is active and assess liver function at initiation of prenatal care.
Prenatal care should be tailored to the pregnancy. There is no modification recommended to decrease mother-to-child transmission (MTCT).
Be aware that intrahepatic cholestasis is more common with HCV.
Women with cirrhosis have a higher rate of adverse outcomes and should be linked to a high-risk obstetrics specialist.
But of course, what seems easy to one specialist may not be true of another. With that in mind, let's hear the ob/gyn perspective on these updated screening recommendations.
The Ob/Gyn Perspective
Recent guidelines from the CDC, ACOG, and SMFM recommend universal screening for HCV in all pregnant women. The increased availability of highly effective antiviral regimens makes universal screening a logical strategy, especially to identify candidates for this curative treatment. What is questionable, however, is the recommended timing by which this screening should take place.
HCV screening during pregnancy, as currently recommended, provides no immediate benefit for the pregnant woman or the fetus/neonate, given that antiviral treatments have not been approved during gestation and there are no known measures that decrease MTCT or change routine perinatal care.
We also must not forget that a significant proportion of women in the United States, particularly those with limited resources, do not receive prenatal care at all. Most of them, however, will present to a hospital for delivery. Consequently, compliance with screening might be higher if performed at the time of delivery rather than antepartum.
Deferring screening until the intrapartum or immediate postpartum period, at least until antiviral treatment during pregnancy becomes a reality, was discussed. The rational was that this approach might obviate the need to deal with the unintended consequences and burden of testing for HCV during pregnancy. Ultimately, ACOG and SMFM fell in line with the CDC recommendations.
Despite the lack of robust evidence regarding the risk for MTCT associated with commonly performed obstetric procedures (eg, genetic amniocentesis, artificial rupture of the membranes during labor, placement of an intrauterine pressure catheter), clinicians may be reluctant to perform them in HCV-infected women, resulting in potential deviations from the obstetric standard of care.
Similarly, it is likely that patients may choose to have a cesarean delivery for the sole purpose of decreasing MTCT, despite the lack of evidence for this. Such ill-advised patient-driven decisions are increasingly likely in the current environment, where social media can rapidly disseminate misinformation.
Implications for Pediatric Patients
One cannot isolate HCV screening in pregnancy from the consequences that may potentially occur as part of the infant's transition to the care of a pediatrician.
Even though MTCT is estimated to occur in just 5%-15% of cases, all children born to HCV viremic mothers should be screened for HCV.
Traditionally, screening for HCV antibodies occurred after 18 months of age. In those who test positive, HCV PCR testing is recommended at 3 years. However, this algorithm is being called into question because only approximately one third of infants are successfully screened.
HCV RNA testing in the first year after birth has been suggested. However, even proponents of this approach concur that all management decisions should be deferred until after the age of 3 years, when medications are approved for pediatric use.
In addition, HCV testing would be required again before considering therapy because children have higher rates of spontaneous clearance.
Seeking Consensus Beyond the Controversy
Controversy remains surrounding the most recent update to the HCV screening guidelines. The current recommendation to screen during pregnancy cannot modify the risk for MTCT, has no impact on decisions regarding mode of delivery or breastfeeding, and could potentially cause harm by making obstetricians defer necessary invasive procedures even though there are no data linking them to an increase in MTCT.
Yet after extensive debate, the CDC, USPSTF, AASLD/IDSA, ACOG, and SMFM all developed their current recommendations to initiate HCV screening during pregnancy. To make this successful, screening algorithms need to be simple and consistent across all society recommendations.
HCV antibody testing should always reflex to the diagnostic test (HCV PCR) to allow confirmation in those who test positive without requiring an additional blood test. Viremic mothers (ie, those who are HCV-positive on PCR) should be linked to a provider who can discuss prognosis, transmission, and treatment. The importance of screening the infant also must be communicated to the parents and pediatrician alike.
Nancy S. Reau, MD, is chief of the hepatology section at Rush University Medical Center in Chicago and a regular contributor to Medscape. She serves as editor of Clinical Liver Disease, a multimedia review journal, and recently as a member of HCVGuidelines.org, a web-based resource from the AASLD and the Infectious Diseases Society of America, as well as educational chair of the AASLD hepatitis C special interest group. She continues to have an active role in the hepatology interest group of the World Gastroenterology Organisation and the American Liver Foundation at the regional and national levels.
Luis D. Pacheco, MD, is a professor in the department of obstetrics and gynecology, division of maternal-fetal medicine, and the department of anesthesiology, division of surgical critical care, and the director of the obstetrical ICU, at the University of Texas Medical Branch in Galveston, Texas. He is triple board-certified in obstetrics and gynecology, maternal-fetal medicine, and critical care medicine. Dr. Pacheco is the editor of multiple textbooks and author of over 70 peer-reviewed articles.
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Cite this: HCV Screening in Pregnancy: Reducing the Risk for Casualties in the Quest for Elimination - Medscape - Nov 22, 2021.