Vertical transmission of hepatitis B refers to the spread of an infection or other disease from mother to child through the placenta or during delivery.
HBsAg is the first marker to appear in the serum of a hepatitis B infected person. In contrast, HBeAg corresponds to the replication of the virus. For this reason, when a woman presents both markers, the probability of transmitting the infection to her offspring is 65-90%.
On the other hand, these percentages are reduced to 5-30% when the woman only presents HBsAg.