Infants infected with hepatitis B virus (HBV) by their mothers during the perinatal period have a risk for developing life-threatening chronic conditions such as liver disease and liver cancer of as much as 90 percent.
The good news is that transmission of maternal infection to the infant can be prevented through administration of vaccine and preventive medication within 12 hours of birth. That's why it's important for pregnant women to be screened for HBV early in pregnancy.
To offer guidance on this topic, the U.S. Preventive Services Task Force (USPSTF) posted a draft recommendation statement(www.uspreventiveservicestaskforce.org) and draft evidence review(www.uspreventiveservicestaskforce.org) discussing HBV screening in pregnancy on Jan. 8.
Based on its review of the evidence, the USPSTF recommended screening pregnant women for HBV infection at their first prenatal visit to prevent infection in newborns; this is an "A" recommendation.(www.uspreventiveservicestaskforce.org)
"Screening for hepatitis B really matters," said task force member Melissa Simon, M.D., M.P.H., in a news release.(www.uspreventiveservicestaskforce.org) "Since 1998, rates of maternal hepatitis B virus have increased annually by 5.5 percent. With early screening, we can treat pregnant individuals and substantially reduce transmission of the virus to their babies."
- The U.S. Preventive Services Task Force (USPSTF) posted a draft recommendation statement and draft evidence review on Jan. 8 that covers screening for hepatitis B virus (HBV) infection in pregnant women.
- Based on its review of the evidence, the USPSTF recommended screening pregnant women for HBV at their first prenatal visit to prevent infection in newborns.
- This draft recommendation is consistent with the task force's 2009 final recommendation on the same topic, which the AAFP supported at the time.
Screening for HBV in pregnancy has been a standard of care for more than 30 years and has borne an A recommendation from the USPSTF since 1996, the first time the task force reviewed the topic, the group said. Most recently, the task force examined the issue in 2009, delivering a final recommendation(www.uspreventiveservicestaskforce.org) that the AAFP fully supported.
For this latest draft statement, the USPSTF commissioned a targeted review to seek new and substantial evidence on the benefits and harms of screening, ultimately determining that the net benefit of screening for HBV infection in pregnant women continues to be well established and, therefore, reaffirming its recommendation to screen pregnant women for the infection.
Draft Recommendation Details
Given that case management is the standard intervention for HBV-positive pregnant women in the United States, the task force focused its evidence review on both the effectiveness and potential harms of screening and the effectiveness and harms of case management to prevent perinatal transmission.
The primary screening test to detect maternal HBV infection is serologic identification of hepatitis B surface antigen (HBsAg). Serological immunoassays for detecting HBsAg have a reported sensitivity and specificity greater than 98 percent.
Although no studies that directly assessed the benefits or harms of universal HBV screening during pregnancy were identified, two fair-quality observational studies reported perinatal transmission rates (primary outcome) over time.
One study reported outcomes of case management from 1994-2008 for more than 155,000 infants born to HBV-positive women in the national Perinatal Hepatitis B Prevention Program (PHBPP), which the CDC administers. During that period, the estimated number of infants born to HBV-positive women rose from 19,208 to 25,600. The proportion of infants born to HBV-positive women enrolled in the PHBPP also increased during this period, rising from 42.1 percent to 47.9 percent.
Perinatal transmission outcomes were reported for infants born from 1999 to 2008 who received serologic testing, and there was a statistically significant decrease in the perinatal transmission rate. Specifically, 1.9 percent of infants who received serologic testing in 1999 were infected with HBV; this rate decreased to 0.8 percent by 2008.
The second observational study was conducted at Kaiser Permanente Northern California. This case management program reported on 4,446 infants born to HBV-positive women from 1997 to 2010.
More than 97 percent of the infants received HBV vaccination and hepatitis B immune globulin (HBIG) within 12 hours of birth. The USPSTF said overall rates of perinatal transmission were very low (0.75 percent), and a decreasing trend in perinatal transmission was reported (incidence rate ratio 0.90).
Family Physician's Perspective
According to Jeffrey Quinlan, M.D., of Alexandria, Va., a member of the AAFP's Commission on Health of the Public and Science, about 24,000 infants in the United States are born with HBV infection every year. And more than 30 percent of people who develop chronic hepatitis B acquired it through perinatal transmission.
Chronic hepatitis, he added, increases a patient's risk of morbidity (such as hepatic carcinoma) and morbidity.
"Fortunately, if we both vaccinate (with hepatitis B vaccine) and provide HBIG soon after birth, we can decrease these risks," Quinlan told AAFP News.
It already is common practice for family physicians to screen pregnant women for HBV during the first trimester, he noted. As for additional screening during the first prenatal visit, that should include gonorrhea, chlamydia, syphilis and HIV -- each of which can increase risks for poor maternal and fetal outcomes, Quinlan said.
"Screening is also often done for cystic fibrosis and muscular dystrophy -- although both are ideally done before conception," he noted. Further testing includes screening for anemia and urinary tract infections/asymptomatic bacteriuria, and determining the mother's blood type and rubella immunity status.
"If patients are found to be nonimmune to rubella, they are offered immunization after delivery," he said.
The USPSTF is accepting comments on its draft recommendation statement(www.uspreventiveservicestaskforce.org) and draft evidence review(www.uspreventiveservicestaskforce.org) until 8 p.m. ET on Feb. 4. All comments received will be considered as the task force prepares its final recommendation.
The AAFP will review the USPSTF's draft recommendation statement and supporting evidence, and will provide comments to the task force. The Academy will release its own recommendation on the topic after the task force finalizes its guidance.
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