Prenatal Screening for and Prevalence of Hepatitis B Surface Antigen in Pregnant Women and Prevention of Transmission to Infants Born to Infected Mothers-Guam, 2014

Abstract

Background: Perinatal transmission is the major mode of hepatitis B virus (HBV) transmission and drives HBV endemicity in the US territory of Guam. We assessed correlates of prenatal hepatitis B surface antigen (HBsAg) screening and HBsAg positivity among pregnant women and evaluated the care of infants of HBsAg-positive women.

Methods: Demographic and clinical data were abstracted from the maternal medical records of 966 randomly selected live infants born in 2014. Frequencies were calculated, and prevalence ratios (PRs) and 95% confidence intervals (CIs) were estimated using Poisson regression.

Results: Among the mothers of the 966 infants, 78.2% were Pacific Islanders, 56.9% were >25 years old (born before universal infant hepatitis B vaccination in Guam), 89.0% received prenatal care (PNC), 96.7% underwent prenatal HBsAg screening, and 2.0% were HBsAg positive. Approximately 15% of the women who did not have PNC were not screened for HBsAg. Receipt of PNC was associated with HBsAg screening (adjusted PR, 1.13 [95% CI, 1.04-1.23]), and HBsAg positivity was associated with a maternal age of >25 years (adjusted PR, 6.80 [95% CI, 1.32-35.08]). All 18 infants of the HBsAg-positive mothers received hepatitis B vaccine, and 17 (94.4%) received hepatitis B immunoglobulin.

Conclusion: Although the prenatal HBsAg screening prevalence in this sample was high, the maternal HBsAg prevalence among women in this sample was more than 14 times and 2 times the prevalence among US-born Pacific Islander/Asian women and all women in the continental United States, respectively. Improving access to PNC, ensuring that all pregnant women in Guam (especially those born before universal hepatitis B vaccination) are screened for HBsAg, and adopting postexposure prophylaxis for infants of HBsAg-positive mothers as standard clinical practice are important for preventing perinatal HBV transmission and reducing HBV endemicity.