All pregnant women should be routinely tested for HBsAg at the first prenatal visit even if they have been previously vaccinated or tested.
If HBsAg is negative, risk factors (IV drug abusers, multiple sex partners, sex partner of HBsAg positive person, health care personnel,multiple blood transfusion receivers, traveller to high incidence areas, patient of chronic liver diaease or HIV) for acquiring HBV (Hepatitis B virus) should be assessed. If risk factors are present, the provider should order HBV vaccination during pregnancy or postpartum. If vaccination does not occur, HBsAg testing should be performed again at delivery.
If HBsAg is positive, a complete serology panel should be performed as well as HBeAg to assess infectivity. Liver enzymes (AST, ALT), and a HBV DNA level (HBV viral load) are also recommended. If HBeAg is positive, HBV DNA is >20,000 IU/mL, or ALT greater or equal to 19 IU/L, referral to a specialist (liver or maternal fetal medicine with expertise) during pregnancy is recommended.
The use of antiviral medications [lamivudine, Food and Drug Administration (FDA) category C; tenofovir, FDA category B; and telbivudine, FDA category B] in the third trimester of pregnancy in addition to passive-active immunoprophylaxis of the newborn have been shown to further reduce vertical transmission rates in women with high HBV DNA levels (usually defined as >6 to 7 log10 copies/mL).
Vaginal delivery is not contraindicated in a woman with HBV infection. At the time of delivery neonatal active passive immunoprophylaxis is to be followed to reduce transmission to the baby.
Breastfeeding has not been identified as a risk factor for perinatal transmission of HBV.