Statistics show that in the absence of effective interruption of mother-to-child transmission of hepatitis B: 1. 70-80% of pregnant women who are positive for both surface antigen and e antigen of hepatitis B virus are infected with hepatitis B; 2. 38% of pregnant women who are positive for a single surface antigen of hepatitis B virus are infected with hepatitis B; 3. 9% of men who are positive for a single surface antigen of hepatitis B virus are infected with hepatitis B; 4. 85-90% of infected infants develop into chronic carriers of hepatitis B virus.