Amniocentesis in mothers who are hepatitis B virus carriers does not expose the infant to an increased risk of hepatitis B virus infection

Results of mother-to-child transmission in hepatitis B-positive mothers who underwent amniocentesis

PURPOSE

This study aims to analyze whether undergoing amniocentesis during pregnancy in women diagnosed with hepatitis B virus (HBV) infection leads to HBV transmission to newborns.

METHODS

Retrospective data collection was conducted from June 2019 to November 2022 on expectant mothers positive for hepatitis B surface antigen (HBsAg) who underwent amniocentesis at The Third Affiliated Hospital of Sun Yat-sen University, along with data on their newborns. The study summarized the HBV infection status of newborns born to mothers with different expressions of hepatitis B e antigen (HBeAg), antiviral treatment versus no treatment, and different HBV DNA viral loads before delivery.

RESULTS

In this study, 346 expectant mothers tested positive for HBsAg, along with 351 newborns (including 5 sets of twins, with 8 infants (2.28%) testing HBsAg-positive at birth. All newborns received dual immunotherapy and were followed up. At 7-12 months, retesting for HBsAg positivity and HBV DNA positivity among infants revealed that out of the infants born with HBsAg positivity, 7 cases had seroconverted to negative, while the remaining infant, who was positive for both HBsAg and HBeAg at birth, tested positive for both HBsAg and HBV DNA at 7-12 months. Thus, one case of vertical transmission of hepatitis B from mother to child occurred in this study. The proportion of infants born with HBsAg + among newborns born to HBeAg-positive mothers (4 cases, 6.06%) was significantly higher than that among newborns born to HBeAg-negative mothers (4 cases, 1.41%) (P < 0.05). The proportion of infants born with HBsAg + showed no significant difference between newborns born to mothers receiving antiviral therapy (2 cases, 2.90%) and those born to mothers not receiving antiviral therapy (6 cases, 2.13%) (P > 0.05). Among expectant mothers with viral load ≥ 6 log 10 IU/mL before delivery, 3 newborns (30.00%) were manifesting HBsAg positivity at birth, significantly higher than the group with viral load < 6 log 10 IU/mL before delivery (5 cases, 1.47%) (P < 0.05).

CONCLUSION

Among HBsAg-positive expectant mothers, only a small number of infants are infected with the hepatitis B virus at birth, the proportion of which is relatively low. Infants born to mothers who are HBeAg-positive or have a viral load ≥ 6 log10 IU/mL have a higher risk of being born positive.

Society for Maternal-Fetal Medicine Consult Series #69: Hepatitis B in pregnancy: updated guidelines

More than 290 million people worldwide, and almost 2 million people in the United States, are infected with hepatitis B virus, which can lead to chronic hepatitis B, a vaccine-preventable communicable disease. The prevalence of chronic hepatitis B infection in pregnancy is estimated to be 0.7% to 0.9% in the United States, with >25,000 infants born annually at risk for chronic infection due to perinatal transmission. Given the burden of disease associated with chronic hepatitis B infection, recent national guidance has expanded both the indications for screening for hepatitis B infection and immunity and the indications for vaccination. The purpose of this document is to aid clinicians caring for pregnant patients in screening for hepatitis B infection and immunity status, discuss the perinatal risks of hepatitis B infection in pregnancy, determine whether treatment is indicated for maternal or perinatal indications, and recommend hepatitis B vaccination among susceptible patients. The following are the Society for Maternal-Fetal Medicine recommendations: (1) we recommend triple-panel testing (hepatitis B surface antigen screening, antibody to hepatitis B surface antigen, and total antibody to hepatitis B core antigen) at the initial prenatal visit if not previously documented or known to have been performed (GRADE 1C); (2) we recommend universal hepatitis B surface antigen screening alone at the initial prenatal care visit for all pregnancies where there has been a previously documented negative triple-panel test (GRADE 1B); (3) we recommend that individuals with unknown hepatitis B surface antigen screening status be tested on any presentation for care in pregnancy; we also recommend that those with clinical hepatitis or those with risk factors for acute hepatitis B infection be tested at the time of admission to a birthing facility when delivery is anticipated (GRADE 1B); (4) we do not recommend altering routine intrapartum care in individuals chronically infected with hepatitis B; administration of neonatal immunoprophylaxis is standard of care in these situations (GRADE 1B); (5) we do not recommend cesarean delivery for the sole indication of reducing perinatal hepatitis B virus transmission (GRADE 1B); (6) we recommend that individuals with HBV infection can breastfeed as long as the infant has received immunoprophylaxis at birth (GRADE 1C); (7) we suggest individuals with hepatitis B infection who desire invasive testing may have the procedure performed after an informed discussion on risks and benefits in the context of shared decision-making and in the context of how testing will affect clinical care (GRADE 2C); (8) in individuals with hepatitis viral loads >200,000 IU/mL (>5.3 log 10 IU/mL), we recommend antiretroviral therapy with tenofovir (tenofovir alafenamide at 25 mg daily or tenofovir disoproxil fumarate at 300 mg daily) in the third trimester (initiated at 28-32 weeks of gestation) as an adjunctive strategy to immunoprophylaxis to reduce perinatal transmission (GRADE 1B); (9) we recommend administering hepatitis B vaccine and hepatitis B immunoglobin within 12 hours of birth to all newborns of hepatitis B surface antigen-positive pregnant patients or those with unknown or undocumented hepatitis B surface antigen status, regardless of whether antiviral therapy has been given during the pregnancy to the pregnant patient (GRADE 1B); and (10) we recommend hepatitis B vaccination in pregnancy for all individuals without serologic evidence of immunity or documented history of vaccination (GRADE 1C).

Risk of mother-to-child transmission after amniocentesis in pregnant women with hepatitis B virus: a retrospective cohort study

BACKGROUND

Amniocentesis is the most widely used invasive prenatal diagnostic sampling technique. However, whether this increases the risk of mother-to-child transmission of infectious diseases remains controversial.

OBJECTIVE

This study aimed to determine whether amniocentesis increases the risk of hepatitis B virus infection in infants who received standard prophylaxis, and to assess the related risk factors for mother-to-child transmission in women who underwent amniocentesis during pregnancy.

STUDY DESIGN

This retrospective analysis used the clinical data of pregnant women with hepatitis B virus infection at West China Second University Hospital, Sichuan University in 2019. After meeting the inclusion criteria, the participants were divided into 2 groups on the basis of whether they had undergone amniocentesis during pregnancy. The infant hepatitis B virus serologic status was followed 1 to 6 months after completion of immunization. The infant testing positive for hepatitis B surface antigen and negative for Hepatitis B surface antibody indicated mother-to-child transmission of hepatitis B virus.

RESULTS

In total, 1764 pregnant women with hepatitis B virus infection were enrolled. Of these, 846 underwent amniocentesis during pregnancy and 918 did not. All offspring received a standardized immunoprophylaxis schedule. The overall mother-to-child transmission rate for hepatitis B virus was 0.6% (5/846) in the amniocentesis group and 0.4% (4/918) in the control group (P=.745). Subgroup analysis showed that the mother-to-child transmission rate in hepatitis B e antigen-positive women was 1.8% (2/111) in the amniocentesis group and 1.0% (2/209) in the control group (P=.612). In women with high viral load, the mother-to-child transmission rate was 1.3% (1/78) vs 0.9% (1/107) (amniocentesis group vs control group; P=1.000). In the amniocentesis group, 31 amniotic fluid specimens had an abnormal appearance (bloody or brown). Univariate analysis showed that the mother-to-child transmission rates of these mothers were statistically higher than those of mothers with pale yellow or transparent amniotic fluid (2/31 vs 3/815; relative risk, 17.527 [3.037-101.151]; P=.012).

CONCLUSION

Amniocentesis did not increase the risk of mother-to-child transmission of hepatitis B virus in infants who received a standardized immunoprophylaxis schedule, including those with mothers who were hepatitis B e antigen-positive or had a high viral load. However, the abnormal appearance (bloody or brown) of the amniotic fluid obtained during amniocentesis may indicate increased risk of mother-to-child transmission for hepatitis B virus.

EASL Clinical Practice Guidelines on the management of liver diseases in pregnancy

Liver diseases in pregnancy comprise both gestational liver disorders and acute and chronic hepatic disorders occurring coincidentally in pregnancy. Whether related to pregnancy or pre-existing, liver diseases in pregnancy are associated with a significant risk of maternal and fetal morbidity and mortality. Thus, the European Association for the Study of Liver Disease invited a panel of experts to develop clinical practice guidelines aimed at providing recommendations, based on the best available evidence, for the management of liver disease in pregnancy for hepatologists, gastroenterologists, obstetric physicians, general physicians, obstetricians, specialists in training and other healthcare professionals who provide care for this patient population.

Vertical Transmission of Hepatitis B Virus-An Update

Hepatitis B virus (HBV) infection is a major public health problem in the world. Approximately 296 million people are chronically infected. In endemic areas, vertical transmission is a common route of transmission. There are several strategies for the prevention of HBV vertical transmission, such as antiviral treatment during the third trimester of pregnancy and immunoprophylaxis to newborns that includes the administration of hepatitis B immune globulin (HBIG) and an HBV vaccine. Despite this, immunoprophylaxis failure can occur in up to 30% of infants born to HBeAg-positive mothers and/or with high viral load. Therefore, management and prevention of HBV vertical transmission is of paramount significance. In this article, we provided a review of the epidemiology, mechanisms of pathogenesis and risk factors of vertical transmission, as well as the strategies implemented to prevent the infection.

Prevention of vertical transmission of hepatitis B virus infection

Hepatitis B virus (HBV) is the leading cause of chronic viral hepatitis. Annually, almost two million children younger than 5 years acquire the infection, mostly through vertical or horizontal transmission in early life. Vertical transmission of HBV is a high efficacy phenomenon ranging, in the absence of any preventive interventions, from 70% to 90% for hepatitis e antigen positive mothers and from 10% to 40% for hepatitis e antigen-negative mothers. Maternal viraemia is a preeminent risk factor for vertical transmission of HBV. Maternal screening is the first step to prevent vertical transmission of HBV. Hepatitis B passive and active immunoprophylaxis at birth together with antiviral treatment of highly viraemic mothers are the key strategies for global elimination of HBV infection. Strategies are needed to promote implementation of birth-dose vaccination and hepatitis B immunoglobulins in low- and middle-income countries where the prevalence of the infection is at the highest.

Mother-to-child transmission of hepatitis B virus after amniocentesis: A retrospective matched cohort study

OBJECTIVE

The objective of this study is to determine whether amniocentesis increases the risk of mother-to-child transmission (MTCT) of hepatitis B virus (HBV) and evaluate risk factors for MTCT.

METHODS

One hundred forty-three hepatitis B surface antigen (HBsAg)-positive women with amniocentesis were enrolled into the amniocentesis group. Six hundred five nonamniocentesis cases were matched with amniocentesis cases based on maternal viral loads, antiviral therapy regimens, and delivery dates. MTCT of HBV was defined as HBsAg and/or DNA positivity in infants from birth to age 7 to 12 months.

RESULTS

Mother-to-child transmission rate was significantly higher in HBsAg-positive women with amniocentesis than in those without amniocentesis (2.80% vs 0.50%; relative risk [RR], 5.64; 95% CI, 1.28-24.93). In the amniocentesis group, maternal HBV DNA more than or equal to 7.0 log₁₀ IU/mL and hepatitis B e-antigen (HBeAg) positivity were associated with higher MTCT rates than maternal HBV DNA less than 7.0 log₁₀ IU/mL (10.81% vs 0%, p = .004) and HBeAg negativity (8.16% vs 0%, p = .013), and antiviral therapy reduced MTCT rate from 14.3% to 0% (p = .554) when maternal HBV DNA was more than or equal to 7.0 log₁₀ IU/mL.

CONCLUSIONS

Amniocentesis increases the risk of MTCT in women with hepatitis B, and maternal HBV DNA more than or equal to 7.0 log₁₀ IU/mL and HBeAg positivity are risk factors for MTCT. Antiviral therapy may be effective to prevent MTCT after amniocentesis in highly viremic mothers.

Management of Hepatitis B Infection in Pregnancy

In many parts of the world, perinatal transmission is the most common route of infection for hepatitis B virus. In the United States, sexual contact is the most common source of hepatitis B virus infection. As a result, it is essential that women's health care providers become aware of the recommended strategies used to identify women infected with hepatitis B and to subsequently reduce perinatal transmission, particularly now that immigration and globalization is more common and reproductive science makes pregnancy more possible for women with liver disease. This article reviews evidence-based strategies for management of hepatitis B infection during pregnancy.

Hepatitis B During Pregnancy in Endemic Areas: Screening, Treatment, and Prevention of Mother-to-Child Transmission

The proper management of pregnant women infected with hepatitis B virus (HBV) is necessary to prevent maternal and fetal morbidity and mortality and to protect the baby from HBV infection. In the majority of cases, vertical transmission can be prevented with a universal screening program, HBV vaccine immunoprophylaxis, and administration of hepatitis B immunoglobulin (HBIg) for babies born to mothers with HBV. However, in mothers with a high viral load (>200,000 or >1,000,000 IU/ml, depending on the guideline), the chance of immunoprophylaxis failure remains high. The standard recommendation is to give an antiviral agent during the third trimester in these patients. US FDA pregnancy category B agents such as tenofovir and telbivudine are allowed through all trimesters of pregnancy. Breastfeeding for patients who receive antiviral agents can be allowed after a risk-benefit discussion with the patient.

Changing indications for invasive testing in an era of improved screening

Prenatal diagnostic testing is available for a growing number of disorders. The goal of prenatal diagnosis was initially focused on the identification of Down syndrome in women aged 35 years and older, but invasive prenatal genetic techniques can now detect a far broader array of conditions. The risks of invasive procedures have also decreased over time. Advances in genomic medicine allow testing for smaller but significant chromosomal abnormalities known as copy number variants, in addition to major aneuploidies and structural rearrangements. Molecular DNA techniques can detect many single-gene conditions. In the future, it is likely that whole-exome and whole-genome sequencing will be applied to prenatal genetic testing to allow identification of yet more genetic disorders. With advances in technology, the indications for testing have likewise evolved far beyond recommendations based solely on maternal age to include a more patient-centered view of the goals of prenatal testing.

#38: Hepatitis B in pregnancy screening, treatment, and prevention of vertical transmission

Between 800,000-1.4 million people in the United States and more than 240 million people worldwide are infected with hepatitis B virus (HBV). Specific to pregnancy, an estimated prevalence of 0.7-0.9% for chronic hepatitis B infection among pregnant women in the United States has been reported, with >25,000 infants at risk for chronic infection born annually to these women. Vertical transmission of HBV from infected mothers to their fetuses or newborns, either in utero or peripartum, remains a major source of perpetuating the reservoir of chronically infected individuals globally. Universal screening for hepatitis B infection during pregnancy has been recommended for many years. Identification of pregnant women with chronic HBV infection through universal screening has had a major impact in decreasing the risk of neonatal infection. The purpose of this document is to aid clinicians in counseling their patients regarding perinatal risks and management options available to pregnant women with hepatitis B infection in the absence of coinfection with HIV. We recommend the following: (1) perform routine screening during pregnancy for HBV infection with maternal HBsAg testing (grade 1A); (2) administer hepatitis B vaccine and HBV immunoglobulin within 12 hours of birth to all newborns of HBsAg-positive mothers or those with unknown or undocumented HBsAg status, regardless of whether maternal antiviral therapy has been given during the pregnancy (grade 1A); (3) In pregnant women with HBV infection, we suggest HBV viral load testing in the third trimester (grade 2B); (4) in pregnant women with HBV infection and viral load >6-8 log 10 copies/mL, HBV-targeted maternal antiviral therapy should be considered for the purpose of decreasing the risk of intrauterine fetal infection (grade 2B); (5) in pregnant women with HBV infection who are candidates for maternal antiviral therapy, we suggest tenofovir as a first-line agent (grade 2B); (6) we recommend that women with HBV infection be encouraged to breast-feed as long as the infant receives immunoprophylaxis at birth (HBV vaccination and hepatitis B immunoglobulin) (grade 1C); (7) for HBV infected women who have an indication for genetic testing, invasive testing (eg amniocentesis or chorionic villus sampling) may be offered-counseling should include the fact that the risk for maternal-fetal transmission may increase with HBV viral load >7 log 10 IU/mL (grade 2C); and (8) we suggest cesarean delivery not be performed for the sole indication for reduction of vertical HBV transmission (grade 2C).

Prenatal invasive procedures in women with hepatitis B, hepatitis C, and/or human immunodeficiency virus infections

OBJECTIVE

To review the risk of in utero infection through prenatal invasive procedures in women with hepatitis B, hepatitis C, and/or human immunodeficiency virus (HIV) infections.

OUTCOMES

Fetal and neonatal morbidity and mortality.

EVIDENCE

Published literature was retrieved through searches of Medline, CINAHL, and the Cochrane Library using appropriate controlled vocabulary (amniocentesis, chorionic villus sampling, cordocentesis, fetal and neonatal infection) and key words (hepatitis B, hepatitis C, HIV). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies from 2002 to 2012 published in English or French. (Studies from 1966 to 2002 were previously reviewed in Clinical Practice Guideline No. 123.) Searches were updated on a regular basis and incorporated in the guideline to February 2014. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table). Recommendations 1. For women infected with hepatitis B, hepatitis C, and/or human immunodeficiency virus, the use of non-invasive methods of prenatal risk assessment is recommended, using tests with high sensitivity and low false-positive rates, such as serum screening combined (or not) with nuchal translucency, anatomic ultrasound, and non-invasive molecular prenatal testing. (III-B) 2. For women infected with hepatitis B, hepatitis C, and/or human immunodeficiency virus undergoing an amniocentesis, every effort should be made to avoid inserting the needle through, or very close to, the placenta. (II-2B) 3. Little information is available on other prenatal diagnostic and therapeutic invasive procedures; the risks and benefits of such procedures should therefore be assessed prior to their use. (III-C) 4. The rate of neonatal hepatitis B infection attributable to amniocentesis ranges up to 1.4% in newborns of mothers positive for hepatitis B surface antigen. However, the rate of neonatal infection attributable to amniocentesis in newborns of mothers with a positive hepatitis B e antigen status may be as high as 16%. Although there is no statistically significant difference between the rates of infection in newborns exposed to amniocentesis or not exposed to amniocentesis in these two maternal populations, knowledge of the mother's hepatitis B e antigen status may be valuable in counselling women about the risks associated with amniocentesis. (II-2A) 5. Amniocentesis in women infected with hepatitis C does not appear to significantly increase the risk of vertical transmission, but women should be counselled that very few studies have properly addressed this possibility (II-2C). More research on this topic is recommended. (III-L) 6. Amniocentesis in women infected with human immunodeficiency virus on combination antiretroviral therapy does not appear to significantly increase the risk of vertical transmission, particularly if the viral load is undetectable, but women should be counselled that data on this issue is limited. (II-2B) 7. For women not on combined antiretroviral therapy, the risk of vertical transmission is increased by performing an amniocentesis. When possible, combined antiretroviral therapy should be initiated and the procedure postponed until the viral load is undetectable. Other case management should be individualized in consultation with infectious diseases specialists and obstetricians. (III-B).

Hepatitis B and C in pregnancy: a review and recommendations for care

Our objective was to provide a comprehensive review of the current knowledge regarding pregnancy and hepatitis B virus (HBV) or hepatitis C virus (HCV) infection as well as recent efforts to reduce the rate of mother-to-child transmission (MTCT). Maternal infection with either HBV or HCV has been linked to adverse pregnancy and birth outcomes, including MTCT. MTCT for HBV has been reduced to approximately 5% overall in countries including the US that have instituted postpartum neonatal HBV vaccination and immunoprophylaxis with hepatitis B immune globulin. However, the rate of transmission of HBV to newborns is nearly 30% when maternal HBV levels are greater than 200 000 IU ml(-1) (>6 log10 copies ml(-1)). For these patients, new guidelines from the European Association for the Study of the Liver (EASL) and the Asian Pacific Association for the Study of the Liver (APASL) indicate that, in addition to neonatal vaccination and immunoprophylaxis, treating with antiviral agents such as tenofovir disoproxil fumarate or telbivudine during pregnancy beginning at 32 weeks of gestation is safe and effective in preventing MTCT. In contrast to HBV, no therapeutic agents are yet available or recommended to further decrease the risk of MTCT of HCV, which remains 3 to 10%. HCV MTCT can be minimized by avoiding fetal scalp electrodes and birth trauma whenever possible. Young women with HCV should be referred for treatment post delivery, and neonates should be closely followed to rule out infection. New, better-tolerated treatment regimens for HCV are now available, which should improve outcomes for all infected individuals.

Risk of vertical transmission of hepatitis B after amniocentesis in HBs antigen-positive mothers

BACKGROUND & AIMS

Despite appropriate immunoprophylaxis, HBV vertical transmission (VT) occurs in 5-10% of infants born to HBs-antigen (HBsAg)+ mothers. We investigated whether amniocentesis increases the risk of transmission.

METHODS

We performed a case-control study on infants who were born to HBsAg+ mothers without antiviral exposure and completed appropriate immunization. Infants born to mothers with amniocentesis were compared to those without amniocentesis to assess VT rates, which were defined by the percentage of infants with HBsAg positivity when they were 7-12 months old.

RESULTS

Of the 642 consecutive infants enrolled, 63 infants with amniocentesis were compared with 198 matched infants selected from the remaining 579 infants without amniocentesis. There was a higher VT rate in infants with amniocentesis than in those without amniocentesis (6.35% vs. 2.53%; p=0.226). Maternal HBV DNA levels before amniocentesis were further stratified to <500 copies/ml, 500-6.99 log10 copies/ml, and ⩾ 7 log10 copies/ml for subset analyses. There were no significant differences in the VT rates between the amniocentesis group and the control group if the maternal HBV DNA levels were <6.99 log10 copies/ml. However, a significantly higher VT rate was observed in the amniocentesis group vs. the control group if the maternal HBV DNA levels were ⩾ 7 log10 copies/ml (50% vs. 4.5%, respectively, p=0.006). According to baseline value risk analyses, performing amniocentesis on highly viremic mothers was a risk factor for HBV transmission (OR=21.3, 95% CI: 2.960-153.775).

CONCLUSIONS

Amniocentesis performed on HBsAg+ mothers with HBV DNA ⩾ 7 log10 copies/ml significantly increased the frequency of VT. HBsAg+ women who plan to have amniocentesis should be evaluated for the risk of VT and stratified according to their HBV DNA levels. Further prospective studies are warranted to verify our findings.

Fetal blood sampling

OBJECTIVE

We sought to review indications, technical aspects, risks, and recommendations for fetal blood sampling (FBS).

METHODS

A systematic review was performed using MEDLINE, PubMed, EMBASE, and Cochrane Library using the terms "fetal blood sampling," "percutaneous umbilical blood sampling," and "cordocentesis." The search was restricted to English-language articles published from 1966 through July 2012. Priority was given to articles reporting original research, in particular randomized controlled trials, although review articles and commentaries also were consulted. Abstracts of research presented at symposia and scientific conferences were not considered adequate for inclusion in this document. Evidence reports and guidelines published by organizations or institutions such as the National Institutes of Health, Agency for Health Research and Quality, American Congress of Obstetricians and Gynecologists, and Society for Maternal-Fetal Medicine were also reviewed, and additional studies were located by reviewing bibliographies of identified articles. Grade (Grading of Recommendations Assessment, Development, and Evaluation) methodology was employed for defining strength of recommendations and rating quality of evidence. Consistent with US Preventive Task Force guidelines, references were evaluated for quality based on the highest level of evidence.

RESULTS AND RECOMMENDATIONS

Ultrasound-guided FBS is the only procedure that provides direct access to the fetal circulation. When invasive testing is planned for suspected severe fetal anemia or thrombocytopenia, we recommend FBS as the procedure of choice, with availability of immediate transfusion if confirmed. We recommend against the use of FBS for indications in which other less invasive, and therefore lower risk, alternatives are available. The overall success rate of FBS is high, and blood samples can be obtained in >98% of patients. We suggest that counseling for FBS include discussion about the potential risk of FBS that may include, but may not be limited to: bleeding from puncture site (20-30%); fetal bradycardia (5-10%); pregnancy loss (≥1.3%, depending on indication, gestational age, and placental penetration); and vertical transmission of hepatitis or human immunodeficiency virus. We recommend that FBS be performed by experienced operators at centers with expertise in invasive fetal procedures when feasible.

Towards complete eradication of hepatitis B infection from perinatal transmission: review of the mechanisms of in utero infection and the use of antiviral treatment during pregnancy

Hepatitis B infection remains the most common form of chronic hepatitis. Mother to child transmission occurs despite immunoprophylaxis with vaccination and immunoglobulin. In utero infection is suggested to account for most of the cases with immunoprophylaxis failure. Infants who suffer from hepatitis B infection at birth have a higher risk of becoming chronic carriers and may develop liver cirrhosis or hepatocellular carcinoma in the future. Infected germ cells, transplacental infection, invasive prenatal diagnostic tests and various perinatal factors are possible factors leading to in utero infection and subsequent immunoprophylaxis failure. Hepatitis B e antigen positive status and high viral load increase the risk of immunoprophylaxis failure. Recent evidence shows promising results regarding the use of antiviral treatment in late gestation to suppress viral load, so as to decrease the risk of vertical transmission. This review discusses the possible mechanisms of in utero infection and the use of antiviral treatment during pregnancy.

Chronic hepatitis B virus infection and pregnancy

Planning of pregnancy and management of chronic hepatitis B virus during pregnancy includes recognition of maternal virological status, assessment of liver disease severity and minimization of risk for mother to infant transmission of infection. Decisions regarding the use of antivirals during pregnancy need to be individualized. Monitoring for infection and immunization in newborns is also important. For mothers on antiviral therapy, breastfeeding is not recommended.

Is hepatitis B virus transmitted via the male germ line? A seroepidemiological study in fetuses

OBJECTIVES

To detect father-to-fetus transmission of hepatitis B virus (HBV) in utero.

METHODS

We conducted a study at the prenatal diagnosis center of Taizhou City. Fetuses with one or both parents carrying the hepatitis B surface antigen (HBsAg) were identified before genetic testing during the period 2008-2010. Intrauterine samples were obtained by amniocentesis or cordocentesis and tested for serological markers and by quantitative DNA assays. All neonates received combined hepatitis B immunoprophylaxis after delivery, and serological follow-up tests were performed at 1 year of age.

RESULTS

Of the 407 couples enrolled in the study, HBV was carried by fathers only in 164, and none of their fetuses were found to be HBV DNA-positive in utero. All fetal serological markers were found to be of maternal but not paternal origin. The response rate to postnatal vaccination was 98.6%, and none of the children who failed immunoprophylaxis were the offspring of the HBV carrier fathers.

CONCLUSIONS

The infection of fetuses with HBV from the spermatozoa of carrier fathers seems unlikely, especially in an area where pre-conception hepatitis B vaccination is routinely provided.

An algorithm for risk assessment and intervention of mother to child transmission of hepatitis B virus

BACKGROUND & AIMS

Despite immunoprophylaxis, mother to child transmission (MTCT) of hepatitis B virus (HBV) still occurs in infants born to hepatitis B surface antigen (HBsAg)-positive mothers. We analyzed methods of risk assessment and interventions for MTCT.

METHODS

We reviewed 63 articles and abstracts published from 1975-2011 that were relevant to MTCT; articles were identified using the PubMed bibliographic database.

RESULTS

Administration of HB immunoglobulin and HB vaccine to infants at birth (within 12 hours), followed by 2 additional doses of vaccines within 6-12 months, prevented approximately 95% of HBV transmission from HBsAg-positive mothers to their infants. However, HBV was still transmitted from 8%-30% of mothers with high levels of viremia. It is important to assess the risk for MTCT and identify mothers who are the best candidates for intervention. The most important risk factor is maternal level of HBV DNA >200,000 IU (10(6) copies)/mL; other factors include a positive test result for the HB e antigen, pregnancy complications such as threatened preterm labor or prolonged labor, and failure of immunoprophylaxis in prior children. Antiviral therapy during late stages of pregnancy is the most effective method to reduce transmission from mothers with high levels of viremia, but elective cesarean section might also be effective. Antepartum administration of HB immunoglobulin, giving infants a double dose of HB vaccine, or avoiding breastfeeding had no impact on MTCT.

CONCLUSIONS

HBsAg-positive mothers should be assessed for risk of MTCT, and infants should receive immunoprophylaxis. Pregnant women with levels of HBV DNA >200,000 IU/mL should be considered for strategies to reduce the risk for MTCT. We propose an algorithm for risk assessment and patient management that is based on a review of the literature and the opinion of a panel of physicians with expertise in preventing MTCT.

Does hepatitis B virus prenatal transmission result in postnatal immunoprophylaxis failure?

The objective of this work was to evaluate whether postnatal hepatitis B immunization failure in children is caused by prenatal infections. A prospective study was conducted from October 2006 to September 2008. Fetal samples from HBsAg-positive mothers were retrieved by either amniocentesis or cordocentesis (percutaneous umbilical blood sampling [PUBS]). Hepatitis B virus (HBV) serologic markers (HBVM) and quantitative HBV DNA assays were performed to assess prenatal infection. All neonates were given combined HBV immunoprophylaxis after delivery. The newborns were followed up with HBV serologic testing at 1 year old. For the 252 pregnant women recruited, 16 fetuses were found to be HBV DNA positive, with all HBV DNA levels under 10(4) copies/ml. HBsAg and HBV DNA detected in the uterus were uncommon and were expressed at low levels. In contract to the case with prenatal statuses, neonatal serologies were more similar to their mothers'. The response rate of vaccination was 95%. Six children for whom immunoprophylaxis failed were born to HBeAg-positive mothers with high HBV DNA levels (>10(8) copies/ml), but only one of them was found to be positive for intrauterine HBV DNA (8.5 × 10(2) copies/ml). The presence of intrauterine hepatitis B antigen and DNA does not indicate postnatal HBV infection and vaccination failure.

Pregnancy and chronic hepatitis B virus infection

The combination of chronic hepatitis B virus (HBV) infection and pregnancy presents unique management questions. Aspects of care that need to be considered include effects of hepatitis B on pregnancy, effects of pregnancy itself on the course of hepatitis B infection, treatment of hepatitis B during pregnancy and prevention of mother-to-infant transmission. Chronic HBV infection is usually mild in pregnant women, but may flare shortly after delivery. Effect of HBV infection on pregnancy outcomes are generally favorable, but may depend on severity of liver disease. Mother-to-infant transmission can be minimized by current immunoprophylaxis strategies, however, high levels of viremia in mothers may be a factor in the small but reproducible failure rate of current immunoprophylaxis strategies. Use of antivirals during pregnancy needs to be individualized. Careful planning and management of pregnancy must be done among patients with chronic HBV infection.

[Amniocentesis and viral risk (hepatitis B, C virus and HIV)]

Very few studies have properly addressed to the risk of fetal hepatitis B (HBV), hepatitis C (HCV) or human immunodeficiency virus (HIV) infection through amniocentesis. For HBV, this risk is low. However, knowledge of the maternal hepatitis B e antigen status is valuable in the counselling of risks associated with amniocentesis. For HCV, the risk is not well known but cannot be excluded. For HIV, it seems rational to propose a viral test before amniocentesis for patients with contamination's risk and to postpone the sampling in cases with positive results in order to obtain an undetectable HIV-1 RNA viral load. For these reasons, it can be useful to analyse for each virus the benefit of amniocentesis and the risk of mother-to-infant transmission, and to inform the patient.

Amniocentesis and women with hepatitis B, hepatitis C, or human immunodeficiency virus

OBJECTIVE

To review the risk of in utero infection through amniocentesis in women with hepatitis B, hepatitis C, or human immunodeficiency virus (HIV).

OUTCOMES

Fetal and neonatal morbidity and mortality.

EVIDENCE

Review articles, meta-analyses, and MEDLINE searches from 1966 to 2002 for English-language articles related to amniocentesis, fetal and neonatal infection, and hepatitis B, hepatitis C, or HIV.

VALUES

The evidence collected was reviewed by the Genetics Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and quantified using the Evaluation of Evidence guidelines developed by the Canadian Task Force on the Periodic Health Exam.

RECOMMENDATIONS

1. The risk of fetal hepatitis B infection through amniocentesis is low. However, knowledge of the maternal hepatitis B e antigen status is valuable in the counselling of risks associated with amniocentesis. (II-1C) 2. Amniocentesis in women infected with hepatitis C does not appear to significantly increase the risk of vertical transmission, but women should be counselled that very few studies have properly addressed this possibility. (II-2C) 3. In HIV-positive women all noninvasive screening tools should be used prior to considering amniocentesis. (II-2D) 4. For women infected with hepatitis B, hepatitis C, or HIV, the addition of noninvasive methods of prenatal risk screening, such as nuchal translucency, triple screening, and anatomic ultrasound, may help in reducing the age-related risk to a level below the threshold for genetic amniocentesis. (II-2C) 5. For those women infected with hepatitis B, hepatitis C, or HIV who insist on amniocentesis, every effort should be made to avoid inserting the needle through the placenta. (II-1B) VALIDATION: These guidelines have been approved by the SOGC Genetics Committee, SOGC Executive, and SOGC Council.

SPONSORS

The Society of Obstetricians and Gynaecologists of Canada.

The presence of hepatitis B surface antigen and deoxyribonucleic acid in amniotic fluid and cord blood

OBJECTIVE

It is uncertain whether neonatal infection with hepatitis B, despite treatment after delivery with immunoglobulin and vaccine, is the result of prior in utero transmission of the virus or treatment failure. Furthermore, the potential risk of hepatitis B transmission from the mother to the fetus at the time a genetic amniocentesis is performed is also a concern. In an attempt to better elucidate these controversies, amniotic fluid and cord blood specimens obtained from pregnant women positive for hepatitis B surface antigen were analyzed for the presence of hepatitis B surface antigen and hepatitis B deoxyribonucleic acid.

STUDY DESIGN

This study was a prospective longitudinal analysis that identified hepatitis B surface antigen-positive patients who presented for amniocentesis. Cord blood was obtained from these patients at the time of delivery. Cord blood was also obtained from a group of hepatitis B surface antigen-positive patients for whom no amniocentesis was performed. All samples were analyzed for the presence of hepatitis B surface antigen and hepatitis B deoxyribonucleic acid.

RESULTS

A total of 121 hepatitis B surface antigen-positive pregnant women were identified. In the 72 pregnancies in which amniocentesis was not performed, 18% of the cord blood samples were positive for hepatitis B surface antigen and 4% were positive for hepatitis B deoxyribonucleic acid. Of 47 amniocentesis fluid samples, 32% were positive for hepatitis B surface antigen but all were negative for hepatitis B virus deoxyribonucleic acid. Of 30 cord blood samples from patients who underwent an amniocentesis, 27% were positive for hepatitis B surface antigen, but all were negative for hepatitis B virus deoxyribonucleic acid.

CONCLUSIONS

This study found that hepatitis B viral deoxyribonucleic acid is rarely present in cord blood and was not identified in amniotic fluid obtained by amniocentesis. This finding suggests that in utero transmission of the virus is rare prior to the onset of labor. These data further confirm the reports in the current literature that the risk of hepatitis B transmission to the fetus during amniocentesis is low. Because hepatitis B surface antigen can exist as an isolated entity devoid of nuclear material, in some cases this protein may be able to traverse the placental and amniotic membrane barrier in a manner similar to other proteins, such as alpha-fetoprotein. Recommendations for genetic amniocentesis in women positive for hepatitis B surface antigen are discussed.

[Mother-child transmission of hepatitis B virus. State of the problem and prevention]

Hepatitis B virus (HBV) infection is a worldwide problem of public health. Mother/child transmission of the virus represents a major factor in maintaining the infection, which is often transmitted during delivery, the risk of transmission of the HBV depending on the degree of maternal infectiosity, the genomic type of the virus, and the rate of maternal antibodies. Evolution towards chronicity of the infected newborn is frequent. The available means to prevent the mother/child transmission of the virus are efficient. Once HBV maternal infection is diagnosed during pregnancy, joint administration of vaccine and specific immunoglobulins to the baby in the early neonatal period efficiently prevent the mother/child transmission of the virus.

Risk of hepatitis B transmission after amniocentesis in chronic hepatitis B carriers

OBJECTIVE

To measure the risk of perinatal transmission of HBV in chronic carriers who undergo amniocentesis.

METHODS

This was a prospective, longitudinal study from 1990 to 1995 of women who were HBV carriers and underwent amniocentesis. The infants of these women were followed from birth to one year of age. Maternal data examined included HBV antigen and antibody status, liver function tests (LFTs) and the amniocentesis report.

RESULTS

Twenty-eight women were identified. Two of 28 neonates were stillborn unrelated to hepatitis. Five infants were lost to follow-up leaving 21 mother-child pairs to evaluate. All 21 women were chronic HBV carriers at the time of amniocentesis for delivery. No mother had abnormal LFTs, and only one of 21 women was positive for hepatitis B e antigen (HBeAg). Thirteen amniocenteses were for advanced maternal age, and four were for abnormal maternal serum alphafetoprotein (MSAFP) screening. None of the amniocenteses were recorded as bloody, and the placenta was anterior in 6 of 21 procedures. None of the 21 infants (95% CI: 0-16.8%) were positive for HbsAg during the first month of life or at 12 months of age. All infants received HBV vaccine and HBIG immunoprophylaxis.

CONCLUSION

The risk of transmission of HBV to the fetus after amniocentesis in women who are HBV carriers is low. Immunoprophylaxis in these infants was successful.

Hepatitis in pregnancy

The study of viral hepatitis was expanded over the past decade with the emergence of new viruses, therapies, and vaccination guidelines as well as new data on the risks of perinatal transmission. There are now at least six hepatitis viruses. Hepatitis A and E are causes of epidemic, enteric infection and do not carry a significant risk of chronic infection. Hepatitis B, C, D, and G are hematogenously spread and are significant causes of chronic hepatitis, hepatocellular carcinoma, and cirrhosis. The following report reviews the types of hepatitis as well as the consequences of infection to the mother and fetus.

Obstetric factors and mother-to-infant transmission of HIV-1

Mother-to-infant HIV transmission has been reported to occur during pregnancy (in utero), at delivery, or postpartum (breast feeding). There are a multiplicity of variables or cofactors that may influence such transmission. Among the obstetric factors reported to be more strikingly associated with mother-to-infant transmission are preterm delivery, low birth weight and birth order in twin pregnancies. Perhaps the most controversial issue in obstetric management is the association of mode of delivery and transmission. Some large studies and metaanalyses have found a protective effect of cesarean section varying from odds ratios of 0.8 to 0.56. Unfortunately, those large studies have not included the duration of rupture membranes in their analyses. When such a variable (duration of ruptured membranes) is taken into account, the protective effect of the cesarean section may disappear. The impact of such obstetric variables on transmission can be explained by the hypothesis that a significant proportion of the perinatal transmission occurs intrapartum and is related to the dose exposure (time and concentration) of the presenting part to the genital tract virus load and to the maternal blood virus load. Currently, routine cesarean section is not recommended as a strategy for the prevention of vertical transmission. Although prospective studies are underway to elucidate the effect of cesarean section on transmission, the results are academic if recent potent antiviral agents are demonstrated to reduce or minimize the viral load in blood and in cervicovaginal secretions. Meanwhile, the current management of the delivery process should have as a goal the reduction of the presenting part to the cervicovaginal secretions by preserving the intactness of the membranes and by the proper use of invasive procedures when clinically indicated.

Risk of fetal infection from invasive procedures

Recent technological advances have led to the development of several types of invasive procedures in the fetus principally for the diagnosis and management of fetal disorders. The risk of infection to the fetus related to these procedures needs evaluation. Although there are few reports of fetal infection, proper infection control procedures must be observed because the most common consequence of infection is fetal loss. Fetal blood sampling in the presence of chorioamnionitis is a risk factor that warrants prophylactic antibiotics. Conversely, clinical specimens taken from the fetus in the absence of chorioamnionitis are more likely to become contaminated with maternal skin flora, and a positive fetal blood culture is not necessarily significant. There is probably a small but finite risk of transmission of maternal viral infections such as human immunodeficiency virus, hepatitis B and C, cytomegalovirus and herpes simplex during invasive procedures. Obstetric departments undertaking invasive fetal diagnosis and treatment must have an adequate policy for infection control procedures.