Today, all pregnant women are routinely screened for hepatitis B, but a growing number of doctors say this single test doesn’t go far enough to protect the health of women and children.
In a commentary published in the medical journal Pediatrics, infectious disease specialist Dr. Ravi Jhaveri calls for a mandatory second test in pregnant women infected with hepatitis B. This test would measure the amount of hepatitis B virus (HBV) in her body (called viral load).
When women have high viral loads, their newborns can become infected even if they are immunized at birth and treated with HBIG (hepatitis B antibodies) to prevent infection.
Dr. Jhaveri, a pediatric infectious disease specialist and associate professor at the University of North Carolina at Chapel Hill School of Medicine, knows this first-hand. He has patients who became infected despite vaccination and HBIG treatment because of their mothers’ high viral loads. Infection occurs when newborns are exposed to these mothers’ highly infectious blood during delivery.
In the past, when anguished parents asked Dr. Jhaveri why their children became infected, he could offer no explanation or treatment to lower the risk. “But now we can,” he told the Hepatitis B Foundation.
Doctors now have potent, antiviral drugs that safely lower viral load in pregnant women and reduce the risk of mother-to-child infection to nearly zero.
Before immunizations, nearly all infants born to infected women developed chronic hepatitis B. Today, immunization within 12 hours of birth and use of HBIG reduces mother-to-child infection by 95 percent.
But despite those prevention efforts, infection still occurs in 3-5 percent of infants born to women who:
- Test positive for the hepatitis B “e” antigen (HBeAg), which is present when viral load is high,
- And have viral loads (HBV DNA) that exceed 20,000 international units per milliliter (IU/mL) or about 1 million copies per milliliter.
Recent studies have confirmed that antiviral drugs, which stop the virus from reproducing, are safe for both mother and child. These drugs, administered in a daily pill, were used for decades in HIV-infected women to lower their viral load and prevent mother-to-child infection.
But here’s the problem: Current guidelines don’t require doctors to take that next step and measure viral load if a pregnant woman tests positive for hepatitis B. As a result, doctors may know a pregnant patient has hepatitis B, but they don’t know if she has a high viral load that requires antiviral treatment.
“We should put in place a system where any pregnant woman who tests positive for the hepatitis B surface antigen (HBsAg) is then tested for the hepatitis B “e” antigen, which is another marker of very high levels of hepatitis B replication, and viral load,” he said. “This could be done on the same blood sample.”
Treating pregnant women with antivirals is not yet approved by the U.S. Food and Drug Administration, however many doctors are prescribing them “off-label” because of the growing number of studies that confirm their safety.
There is another reason that viral load testing early in a woman’s pregnancy is important. Recent studies show that the earlier a woman starts on antivirals during her pregnancy, the lower her risk of infecting her newborn.
“It is clear that we have come a long way in preventing (mother-to-child transmission of HBV). It is also clear that it is time to take the next step,” Dr. Jhaveri wrote in his Pediatrics commentary. “We have the tools available, we just need to have the will.”
Doctors currently recommend one of the newer antivirals, such as tenofovir (brand name Viread) or entecavir (Baraclude), for use in pregnant women. Tenofovir has proven to be safe in pregnant women who have developed resistance to other antivirals, such as lamivudine (Epivir-HBV).
All women with hepatitis B should also be monitored carefully after delivery and women who stop taking antivirals after delivery should also be carefully followed as a sudden increase in her viral load may occur.