Prospective cohort study of children exposed to hepatitis C virus through a pregnancy screening program

Clinical Consensus Statement No. 458: Hepatitis C Virus in Pregnancy

OBJECTIVE

Provide guidance for routine antenatal screening of hepatitis C virus in pregnancy to support best practice and optimize antenatal and infectious disease care.

TARGET POPULATION

Pregnant women/pregnant individuals receiving antenatal care in Canada and consenting to routine infectious disease screening. Options include reviewing prior serology and avoiding repeat testing or providing information regarding the benefit of identifying hepatitis C virus infection for the mother/parent and the baby.

BENEFITS, HARMS, AND COSTS

Benefits may include identifying those eligible for treatment of hepatitis C virus infection, avoiding interventions that may increase the risk of transmission to the baby during labour and delivery, creating opportunities for appropriate screening of newborns, and reducing the burden of hepatitis C virus infection in line with World Health Organization recommendations. No direct harms are present given the possibility of testing for hepatitis C using the blood samples already included in antenatal screening. Psychological distress may occur with a new diagnosis of hepatitis C virus in pregnancy. The costs of identifying asymptomatic cases, with resulting treatment, outweigh the health care costs of this additional test.

EVIDENCE

Published and unpublished literature was reviewed between 2017 and July 2023 (when the prior hepatitis C guideline: No. 96 The Reproductive care of Women Living with Hepatitis C infection, was last endorsed). OVID Medline, Embase, PubMed, and the Cochrane Library databases were searched for relevant publications available in English for each section of this statement. Unpublished literature, protocols, and international guidelines were identified by accessing the websites of health-related agencies, clinical practice guideline collections, and national and international medical specialty societies (i.e., American College of Obstetricians and Gynecologists, Royal College of Obstetricians and Gynaecologists, and Royal Australian and New Zealand College of Obstetricians and Gynaecologists).

VALIDATION METHODS

The evidence was obtained and reviewed by the principal authors with recommendations reviewed by the Infectious Disease Committee of the SOGC (2022). The authors identified these recommendations using a consensus process and rated the quality of evidence and strength of recommendations according to the guidelines developed by the Canadian Task Force on Preventative Health Care (https://canadiantaskforce.ca/methods/; see online Appendix A).

INTENDED AUDIENCE

Health care practitioners providing antenatal care, health care organizations, and provincial and federal governments.

SOCIAL MEDIA ABSTRACT

Universal screening for hepatitis C in pregnancy is recommended.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Role of viral hepatitis in pregnancy and its triggering mechanism

Hepatitis viral infection can cause severe complications, even mortality in pregnant women and their offspring. Multiple studies have shown that vertical transmission can cause viral hepatitis infections in newborns, especially in hepatitis B, C, and E. Screening for hepatitis viral infection in pregnant women is essential. Once infected, pregnant women should be given timely antiviral treatments, which could effectively alleviate the disease progression and reduce adverse outcomes. Besides, the mechanism of viral hepatitis mediating adverse pregnancy outcomes has been a hot topic. Hepatitis B virus has been found to mediate both mother- to-child and parent-child transmission. Liver injury in hepatitis C virus infection is associated with immune-mediated mechanisms, which can be regulated by hormonal factors as well. The mediating mechanism of adverse maternal and infant outcomes caused by hepatitis E virus infection is mainly related to viral replication in the placenta and changes in cytokine and estrogen. Nevertheless, the specific mechanisms related to hepatitis A virus and hepatitis D virus remain unclear, and more research is needed. This review shows that the existence of viral hepatitis during pregnancy can pose certain risks for pregnant women and infants, and different interventions have been used to treat pregnant women infected with viral hepatitis. It may provide deep insight into adverse pregnancy outcomes caused by viral hepatitis and give guidance on treatment.

Influence of hepatitis C viral parameters on pregnancy complications and risk of mother-to-child transmission

BACKGROUND & AIMS

With the World Health Organization plan for hepatitis C elimination by the year 2030, and recent guideline recommendations to screen all women during pregnancy for HCV, data on HCV in pregnancy are needed to determine the association of HCV viremia with adverse pregnancy outcomes and mother-to-child transmission (MTCT).

METHODS

This retrospective cohort study was performed in Ontario, Canada, using population-based administrative healthcare data. Individuals were stratified based on whether they had active HCV viremia during pregnancy or resolved viremia at time of pregnancy. Peak HCV viral load was determined. Logistic regression was used to determine the association of viremia with adverse pregnancy outcomes; maternal HCV RNA levels were evaluated as a predictor of MTCT.

RESULTS

We identified a total of 2,170 pregnancies in 1,636 women who were HCV RNA positive prior to pregnancy; 1,780 (82%) pregnancies occurred in women who were HCV RNA positive during pregnancy. Patients who were HCV RNA positive during pregnancy were more likely to have preterm delivery (18% vs. 12%, p = 0.002), intrahepatic cholestasis of pregnancy (4% vs. <2%, p = 0.003), and post-partum hemorrhage (9% vs. 5%, p = 0.013), and less likely to have gestational diabetes (6% vs. 10%, p = 0.008) than those with resolved infection. Only 511 (29%) infants had screening consistent with guidelines after birth; there was an estimated 3.5% risk of MTCT. HCV RNA ≥6.0 log₁₀ IU/ml was significantly associated with MTCT (exact odds ratio 3.4, p = 0.04).

CONCLUSION

Active HCV viremia among individuals with a history of HCV infection significantly increases adverse pregnancy outcomes. Few infants are screened for MTCT. Higher HCV RNA is associated with increased risk of MTCT.

LAY SUMMARY

The prevalence of hepatitis C has increased in women of child-bearing age and has important implications for women who become pregnant and their infants. We evaluated the effect that hepatitis C has on pregnancy outcomes as well as the rate of hepatitis C transmission to infants in a large database with linked mother-infant records. We found that active hepatitis C during pregnancy increased the risk of pregnancy complications. We also identified very low rates of testing of infants born to mothers with hepatitis C, but found higher rates of hepatitis C transmission to infants in mothers with higher virus levels.