Hepatitis B screening in pregnancy

What it is

Hepatitis B screening in pregnancy is done with HBsAg, it is offered to all pregnant women, and its stated frequency is every pregnancy. That last word is the whole point of the item: the test belongs to the pregnancy and not to the woman, so a negative HBsAg in an earlier pregnancy does not stand in for this one, and the booking visit of a third pregnancy carries the same HBsAg as the first two did. Put as a case: a woman whose earlier pregnancy was HBsAg negative has HBsAg testing at this visit, because the stated frequency is every pregnancy, not the one-time test that hepatitis C screening is in adults 18-79 years.