Cesarean Section Reduces Perinatal Transmission of Hepatitis B Virus Infection From Hepatitis B Surface Antigen–Positive Women to Their Infants

Background & Aims Despite appropriate passive and active immunization, perinatal transmission of hepatitis B virus (HBV) still occurs in 5%–10% of infants born to women with high levels of viremia who test positive for the hepatitis B e antigen (HBeAg). We evaluated the effects of cesarean section delivery on perinatal transmission of HBV from women who tested positive for the hepatitis B surface antigen (HBsAg). Methods We analyzed data from 1409 infants born to HBsAg-positive mothers through vaginal delivery (VD) (n = 673), elective caesarean section (ECS) (n = 496), or urgent cesarean section (UCS) (n = 240) who completed appropriate immunization against HBV. The prevention was assumed to have failed for infants who were HBsAg positive when they were 7–12 months old; this information was used to assess transmission rates. Results HBV infection was transmitted to a smaller percentage of infants born by ECS (1.4%) than by VD (3.4%, P P P  = .593). Infants born by ECS had a significantly lower rate of vertical transmission than those born by non-ECS (1.4% vs 3.6%, P  = .017). Women with HBV DNA levels Conclusions There is a significantly lower rate of vertical transmission of HBV infection to infants delivered by ECS, compared with those delivered vaginally or by UCS. Elective cesarean sections for HBeAg-positive mothers with pre-delivery levels of HBV DNA ≥1,000,000 copies/mL could reduce vertical transmission.