(945) Hepatitis C virus in pregnant individuals with opioid use disorder and association with preterm birth

Objective: To evaluate the association between HCV infection in pregnant individuals with opioid use disorder (OUD) and rates of preterm birth (PTB).

Study Design: We conducted a retrospective cohort study of pregnant individuals with OUD from 2013-2021 who participated in > 3 visits in a co-located prenatal/addiction program. They were included if they had a diagnosis of OUD and HCV status determined during pregnancy. The primary exposure was HCV defined as detected HCV antibodies, and secondarily, among those with HCV, detectable viral load (VL) was defined as HCV RNA VL >12 IU/L). The primary outcome was PTB ( < 37 weeks gestation). PTB was classified into spontaneous PTB (due to preterm labor or with preterm rupture of membranes) and iatrogenic PTB (due to maternal or fetal medical complication necessitating early delivery). Multivariable logistic regression was used to detect associations while adjusting for race, history of prior PTB, and tobacco use.

Results: A total of 941 pregnant individuals were included in the study, 404 with HCV and 537 without. Race (p < 0.01), tobacco use (p < 0.01), bipolar disease (p = 0.04), and being seen by a social worker (p = 0.04) were the factors that significantly differed between both groups. When comparing individuals with and without HCV, rates of overall PTB did not differ (20.3 vs 23.8%, aOR 0.75 [95% CI 0.53-1.07]). Rates of spontaneous PTB (13.1 vs 16.2%, aOR 0.79 [95% CI 0.43-1.45]) and iatrogenic PTB (7.2 vs 7.6%, aOR 1.26 [95% CI 0.69-2.30]) also did not differ. HCV positive individuals with a detectable VL did not have an increased rate of PTB compared to those without (21.6 vs 16.4%, aOR 0.86 [95% CI 0.52-1.44]). Rates of spontaneous (13.3% vs 12.9%, aOR 0.97 [95% CI 0.52-1.87]) and iatrogenic (8.3 vs 5.0%, aOR 1.83 [95% CI 0.76-4.94]) PTB were also similar.

Conclusion: HCV infection does not appear to be associated with higher rates of spontaneous or iatrogenic PTB in our study population, contrary to previous literature. The role of multidisciplinary prenatal and addiction programs on association between HCV and PTB warrants further investigation.