119 Changes in hepatitis B viral loads in pregnancy: a retrospective cohort study

Abstract

The effect of pregnancy on hepatitis B (HBV) viral loads has not been studied. For the past 5 years, our health care organization has recommended testing for HBV DNA levels at early gestational age (GA) and at 24-32 weeks GA. We assessed changes in HBV viral load during pregnancy. A retrospective cohort study of pregnant women with HBV between 2014 and 2019 was performed from database extraction and chart review. Women with non-continuous coverage, concurrent anti-viral therapy, immunosuppressive treatment or unknown viral loads at either early (≤14 weeks) or late (24-32 weeks) GA were excluded. We compared the proportion of women with high HBV viral load (≥200,000 IU/mL) at early versus late GA using McNemar’s test and evaluated the association between hepatitis B e-antigen (HBeAg) status (within 18 months prior to delivery) and high viral load at late GA using univariate logistic regression. 328 women met inclusion criteria, 88% maintained low viral load throughout pregnancy. 9% (30/328) had high viral load at early GA and 11% (36/328) at late GA (p=0.11). 52 women had undetectable viral load (<20 IU/mL) throughout pregnancy. Ten women (3%) progressed from low viral load at early GA to high viral load. Among these 10 women, median HBV viral load at early gestation was 24,850 (IQR 1,701-42,764) IU/mL, none had undetectable viral load at early gestation, and only one woman was positive for HBeAg. Within our study cohort, the odds of having high viral load at late GA was significantly higher among women who were positive for HBeAg (unadjusted OR [95% CI]: 30.5 [13.1, 71.2], p<0.0001). Most women with HBV will maintain low viral load throughout pregnancy; however, a small percentage may progress to high viral load. Clinically, the optimal time to assess viral load is at 24-32 weeks in order to identify women who will benefit from treatment to prevent vertical transmission.View Large Image Figure ViewerDownload Hi-res image Download (PPT)