Hepatitis B in pregnancy

What it is

Hepatitis B virus is transmitted by exposure to the blood or body fluids of an infected person, including injection drug use, sexual contact with an infected person, and transmission by an infected mother to her infant during delivery. That last route is the one that matters at delivery, and the answer to it is given in the first day of the infant's life.

How it presents

Persons with hepatitis B may have an anicteric or subclinical acute infection, and the symptoms of acute hepatitis B are similar to those of acute hepatitis A. The characteristic findings are increases in the serum aminotransferase levels, AST and ALT.

How it is diagnosed

HBV infection runs through several stages, though not every patient goes through each one:

1. HBeAg positive chronic HBV infection, formerly called the immune-tolerant phase: a normal ALT despite a very high HBV DNA level, and this is the one a patient who acquires the infection at birth often goes through.
2. The inactive carrier stage, now called HBeAg negative chronic hepatitis B: a normal ALT and an HBV DNA level under 2,000 U/mL, sometimes defined as under 20,000 U/mL.
3. The HBeAg positive immune active phase: an elevated ALT with an HBV DNA level above 20,000 U/mL.
4. The HBeAg negative immune escape phase: an elevated ALT with an HBV DNA level above 2,000-10,000 U/mL.