Abstract

Background: With the ongoing opioid epidemic, hepatitis C virus (HCV) prevalence in women of childbearing potential has increased in North America. As pregnancy may be the only time many women interact with the healthcare system, it presents an opportune time for HCV screening and linkage to care. Poor postpartum follow-up may justify treatment in pregnancy, but there is currently little known about the cascade of care for women of childbearing potential with HCV in pregnancy or postpartum.

Methods: We performed a population-based retrospective cohort study linking pregnancies between 2008 and 2020 to HCV testing records (spanning 1999 to 2020) and health administrative data in Ontario, Canada. Pregnancies were identified using algorithms that detected pregnancy loss <20 weeks, induced abortion, prenatal ultrasound, livebirths, and stillbirths ≥20 weeks. We determined whether individuals tested positive for HCV antibody (Ab+), were RNA tested, RNA+, and/or initiated treatment. Kaplan Meier methods were used to model time from Ab+ to subsequent RNA test, and from first RNA+ record to treatment. Missed opportunities for engagement in HCV care were defined as pregnancies that occurred following Ab+ prior to subsequent RNA test, and following first RNA+ record prior to treatment initiation.

Results: We identified 13,432 individuals with HCV Ab+ and/or RNA test(s) and ≥1 pregnancy record (corresponding to 28,761 pregnancies). Of these, 2,868 (21.4%) had their earliest Ab+ test record during a pregnancy. Of individuals ever Ab+,11,668 (86.9%) received RNA testing and 2,668 (22.9%) had their earliest RNA test during a pregnancy. Of the 4,945 individuals ever RNA+ without spontaneous clearance, 2,057 (41.6%) initiated treatment. Time to RNA test from Ab+ record improved from 47.5 (95% CI:41.7-53.7) weeks prior to 2012 to 5.7 (95% CI:5.2-6.8) weeks after 2018. Time to treatment from RNA+ improved from 15.1 (95% CI:14.1-16.2) years prior to 2012 to 1.9 (95% CI:1.6-2.2) years after 2018. Of those with their earliest Ab+ test (N=9,527), 1,956 (20.1%) had ≥1 pregnancy before a subsequent RNA test. Treatment occurred in the minority with a RNA+ record. Following those from their first RNA+ (N=4,936), 2,266 (45.9%) had ≥ 1 pregnancy before initiating treatment (Figure). There were 1,767 individuals never linked to an RNA test corresponding to an average of 1.6 missed pregnancies per person. Considering the 2,212 missed pregnancies among those RNA+ with no treatment record (assuming clearance of 40% and 5% vertical transmission rates), we estimate 195 infected infants may have been a consequence of these missed opportunities for engagement.

Conclusion: We observed significant gaps in follow-up testing after initial Ab+ test, and in treatment following an RNA+ result. It will be critical to enhance linkage after HCV diagnosis during or before pregnancy to reduce transmission, particularly following adoption of universal HCV screening in pregnancy.