Hepatitis B and Pregnancy: An Underestimated Issue

Maureen M. Jonas

Disclosures

Liver International. 2009;29(s1):133-139. 

In This Article

Vaccination Against Hepatitis B Virus During Pregnancy

Vaccination against HBV is both safe and efficacious during pregnancy.[22,23] In addition, passive transfer of maternal antibody to newborns has been demonstrated, although without the addition of active vaccination, titres in the infants were noted to wane over time,[22] as would be expected.

Treatment for Hepatitis B Virus During Pregnancy

There are two principal indications for administration of antiviral agents to HBV-infected pregnant women: treatment of chronic hepatitis in the mothers and prevention of perinatal HBV transmission to the newborns.

Most women with chronic HBV infection have mild liver disease during pregnancy, although hepatitis may flare after delivery, as described above. In addition, interferon, lamivudine, adefovir and entecavir are classified by the Food and Drug Administration as Class C, and telbivudine and tenofovir as Class B. In most cases, this is because there are insufficient data in humans to demonstrate teratogenic or embryotoxic effects. For these reasons, in most instances, it is reasonable to defer therapy until after delivery, to avoid fetal exposure to the therapeutic agents. After delivery, standard therapy indications, as expressed in the several available HBV guidelines, will apply. However, if maternal liver disease requires treatment, or if a pregnancy occurs in a woman already receiving a medication for HBV, decisions must be made about treatment course.

There is a long history of use of lamivudine during pregnancy, both for women with HIV infection and for those with chronic HBV. Data from the Antiretroviral Pregnancy Registry 2006[24] indicate that the rate of birth defects among women exposed to lamivudine was similar to that in the general population. In one cohort of 38 HBV-infected women who became pregnant while taking lamivudine and elected to continue the treatment throughout the pregnancy, there were no pregnancy complications, no instances of fetal injury and no cases of perinatal HBV transmission.[25] This compared favourably to historical rates of HBV transmission from the same population in which active and passive immunization was used routinely. In addition, 35 of the 38 women were no longer viraemic with HBV, and 10 (26.3%) had HBeAg seroconversion. Two women who elected to discontinue lamivudine during their pregnancies developed active hepatitis (abnormal ALT) within 6 months.[25] This study was small, and the authors concede that more data are needed, but there is some support for the safety of lamivudine in this group. There are no comparable studies of other antiviral agents for HBV.

At this point, there are no standards regarding managing HBV in women who become pregnant while receiving antiviral therapy. One option is discontinuation of treatment as soon as the pregnancy is recognized. This is an option only for those with mild hepatitis, with a low risk of serious flare or disease progression. Other possibilities include continued careful monitoring or change of therapy to lamivudine, either temporarily or permanently, acknowledging the risk of development of resistance.

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