Abstract
Objective: To know the correlation between quantitative Hepatitis B surface Antigen (HbsAg) and maternal Hepatitis B Envelope Antigen (HbeAg) with hepatitis B intrauterine transmission via placental infection. Hepatitis B in pregnancy causes a mother to child transmission (MTCT) via transplacental route started with placental infection. HBV DNA viral load and HBeAg are the independent risk factors for MTCT, but it rarely available in developing country. Materials and methods: A cross-sectional study in 33 pregnant women with HbsAg positive in 4 referral hospital in East Java, Indonesia. Quantitative HBS Ag and HBeAg) status were determined serologically from a peripheral venous blood sample. Placental Hepatitis B infection was detected by immunohistochemistry of HBsAg from placental tissues. The intrauterine transmission was diagnosed by positive HBsAg in cord blood sampling after deliveries. Results: Serum quantitative HBsAg level has a good sensitivity and spesificity to predict placental infection (90% and 83%), with a cut off value of 3.14 Log10 IU/mL (AUC 0.87; 95% CI: 0.74-0.99). Quantitative HBsAg level also has a good sensitivity and spesificity to predict HBV transmission in umbilical blood cord (81.8% and 95.5%) with a cut off value of 3.62 log(10) IU/ml (AUC: 0.925, 95% CI: 0.813-1; p = 0.000). Placental infection is significantly related with intrauterine transmission with OR 4.6 (95% CI 2.29-9.4; p = 0.002). Conclusion: The study reveals that maternal serum quantitative HBsAg level can be used as an alternative test to substitute HBeAg or HBV DNA as a marker to predict the placental infection and intrauterine transmission, especially in low-middle income countries.