Hepatitis B May Resurface Postpartum
A condition necessary to perpetuate our species, pregnancy is a normal and healthy state. Even though the nine months of pregnancy cause many pregnant women to seem at their healthiest and most robust, some compromises to the expectant mother’s immunity can surface. In addition to being more prone to certain infections during a pregnancy, some women are extremely vulnerable to problems after delivering the baby. In those who are carriers of the Hepatitis B virus (HBV), researchers from the Netherlands have demonstrated a vulnerability to relapse.
Estimated by experts to be 100 times more infectious than the virus that causes AIDS, HBV has infected approximately two billion people worldwide; or one out of every three individuals. Luckily, the majority of healthy adults who are infected with HBV will recover and develop protective antibodies against future Hepatitis B infections. Only about 10 percent of those with HBV will be unable to get rid of the virus and go on to develop a chronic liver infection.
While routine HBV vaccination at birth has slowed the rate of new infections, statistics still compute that between 10 and 30 million new infections occur globally each year. However, when introducing the likelihood that a common event like pregnancy can potentially reactivate those who have previously recovered from HBV infection, a more cautionary approach to latent infection is warranted.
Immunity and Pregnancy
During pregnancy and just after birth, women are more susceptible to infections, whether it is a new infection or worsening of a dormant one. One of the most intriguing puzzles in modern immunology involves the paradox of pregnancy. This irony is defined by an immunologic tolerance to antigens from the father, despite an apparently adequate maternal defense against infection.
With 50 percent of its genetic material derived from the father, a fetus’s susceptibility to rejection by the maternal immune system is similar to the susceptibility of a transplanted organ. Though, nature lessens this risk by altering the mother’s immunity. Evidence indicates that the maternal immune system may tolerate fetal antigens by suppressing her own immune system. Some of the specific changes in a woman’s immune system during pregnancy, include:
- Increased production of macrophages (cells that destroy bacteria). This improves antibody response and helps to protect against bacteria.
- Decreased activity of NK cells (natural killer cells destroys cells that have been infected with a virus or that are part of a tumor).
- Decreased activity of T cells, which help to control infections caused by viruses.
- Decreased production of cytokines (which are released from immune cells to recruit other cells to help fight infection).
Although pregnant women are not immuno-suppressed in the classic sense, immunologic changes of pregnancy may explain their increased susceptibility to certain pathogens, including viruses, bacteria and parasites.
Most mothers would agree that giving birth is the single most major event the female body could possibly endure. Sometimes traumatic – but always reminiscent of a miracle – a woman who has just given birth requires a recovery period. During the time it takes for a woman’s body to adjust and heal from delivery, an increase in vulnerability to infection occurs.
The scientific community agrees that little is known about the immunological recovery in postpartum women. However, physicians do know that many physiological changes occur, such as uterine involution and recovery of non-pregnant immune status. These changes are likely to affect susceptibility to disease.
Hepatitis B Postpartum Study
Researchers from the Netherlands have investigated the evolution of liver disease in women with HBV during and after pregnancy. As published in the January 2008 edition of the Journal of Viral Hepatitis, the researchers concluded that, “A significant increase in liver inflammation occurs often after pregnancy. This may be due to a reactivation of the immune system after delivery.”
Some participants in this study had chronic HBV and some were considered to be carriers of the virus. The results showed a significant increase in liver disease activity within six months after the mothers gave birth. Based on characteristics such as the mother’s status as having chronic liver disease or being an HBV carrier, the authors stated that it was not possible to predict during pregnancy which women would experience liver disease exacerbations. This means that regardless of the status of HBV infection, pregnant women who have been infected with HBV are susceptible to its resurgence following delivery.
Likely due to the immunologic changes that accompany a woman as she gestates and produces a new human being, the Hepatitis B virus can flourish in a pregnant woman’s body. Because so many people have antigens to HBV, this possibility must be known to expectant mothers and their caregivers.
Groer, Maureen Wimberly, et al., Immunity, Inflammation and Infection in Postpartum Breast and Formula Feeders, American Journal of Reproductive Immunology, October 2005.
www.babycenter.com, Postpartum Infections, BabyCenter LLC, 2008.
www.cdc.gov, Emerging Infections and Pregnancy, Denise J. Jamieson, et al, Centers for Disease Control and Prevention, November 2006.
www.healthline.com, Infections in Pregnancy, Healthline Networks, Inc., 2008.
www.hepb.org, Hepatitis B Statistics, Hepatitis B Foundation, 2008.
www.hivandhepatitis.com, Hepatitis B Exacerbation May Occur in Women after Giving Birth, hivandhepatitis.com, 2008.
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