The virus is transmitted by parenteral route, sexual contact, veical transmission and rarely breast milk. The risk of transmission to fetus ranges from 10% in 1st TM to as high as 90% in 3rd TM. It is specifically high (90%) from those mothers who are seropositive to hepatitis B surface Antigen(HBsAg) and e-antigen(HBeAg) Reference: Textbook of Dutta,9th edition, page 271