Hepatitis B:

the hepatitis B screening test is called hepatitis B surface antigen. It detects a protein produced by the virus and can detect a hepatitis B infection even before it causes symptoms. If a woman who is considering getting pregnant tests positive for hepatitis B, she should talk to her healthcare practitioner about how long she should wait to allow the infection to resolve before becoming pregnant.

It is important to detect active hepatitis B infections in pregnant women because newborns are especially vulnerable to developing chronic infection. If a hepatitis infection is detected in a pregnant woman, she can be monitored and the baby can receive treatment at birth to minimize the risk of it developing hepatitis B.

A negative test for the virus means either that there is no current infection or there is not yet a sufficient amount of the antigen to be detected. If a woman participates in high-risk activities that may transmit the hepatitis B virus (such as unprotected sexual contact or intravenous drug use), retesting later in the pregnancy is generally advised.