Systematic review with meta-analysis: the efficacy and safety of tenofovir to prevent mother-to-child transmission of hepatitis B virus

Tenofovir and Hepatitis B Virus Transmission During Pregnancy: A Randomized Clinical Trial

Importance

Standard care for preventing mother-to-child transmission (MTCT) of hepatitis B virus (HBV) in highly viremic mothers consists of maternal antiviral prophylaxis beginning at gestational week 28 combined with an HBV vaccine series and HBV immune globulin (HBIG) at birth. However, HBIG is unavailable in some resource-limited areas.

Objective

To determine whether initiating tenofovir disoproxil fumarate (TDF) at gestational week 16 combined with HBV vaccinations for infants is noninferior to the standard care of TDF at gestational week 28 combined with HBV vaccinations and HBIG for infants in preventing MTCT in mothers with HBV and high levels of viremia.

Design, Setting, and Participants

An unblinded, 2-group, randomized, noninferiority clinical trial was conducted in 7 tertiary care hospitals in China. A total of 280 pregnant individuals (who all identified as women) with HBV DNA levels greater than 200 000 IU/mL were enrolled between June 4, 2018, and February 8, 2021. The final follow-up occurred on March 1, 2022.

Interventions

Pregnant individuals were randomly assigned to receive either TDF starting at gestational week 16 with HBV vaccinations for the infant or TDF starting at gestational week 28 with HBV vaccinations and HBIG administered to the infant.

Main Outcomes and Measures

The primary outcome was the MTCT rate, defined as detectable HBV DNA greater than 20 IU/mL or hepatitis B surface antigen positivity in infants at age 28 weeks. Noninferiority was established if the MTCT rate in the experimental group did not increase by more than an absolute difference of 3% compared with the standard care group, as measured by the upper limit of the 2-sided 90% CI.

Results

Among 280 pregnant individuals who enrolled in the trial (mean age, 28 years; mean gestational age at enrollment, 16 weeks), 265 (95%) completed the study. Among all live-born infants, using the last observation carried forward, the MTCT rate was 0.76% (1/131) in the experimental group and 0% (0/142) in the standard care group. In the per-protocol analysis, the MTCT rate was 0% (0/124) in the experimental group and 0% (0/141) in the standard care group. The between-group difference was 0.76% (upper limit of the 2-sided 90% CI, 1.74%) in all live-born infants and 0% (upper limit of the 2-sided 90% CI, 1.43%) in the per-protocol analysis. Both comparisons met the criterion for noninferiority. Rates of congenital defects and malformations were 2.3% (3/131) in the experimental group and 6.3% (9/142) in the standard care group (difference, 4% [2-sided 95% CI, -8.8% to 0.7%]).

Conclusions and Relevance

Among pregnant women with HBV and high levels of viremia, TDF beginning at gestational week 16 combined with HBV vaccination for infants was noninferior to the standard care of TDF beginning at gestational week 28 combined with HBIG and HBV vaccination for infants. These results support beginning TDF at gestational week 16 combined with infant HBV vaccine to prevent MTCT of HBV in geographic areas where HBIG is not available.

Trial Registration

ClinicalTrials.gov Identifier: NCT03476083.

Tenofovir Alafenamide Versus Tenofovir Disoproxil Fumarate for Preventing Vertical Transmission in Chronic Hepatitis B Mothers: A Systematic Review and Meta-Analysis

OBJECTIVE

International guidelines recommend maternal tenofovir disoproxil fumarate (TDF) therapy accompanied by infant immunoprophylaxis to prevent hepatitis B virus (HBV) mother-to-child transmission (MTCT) in highly viremic mothers. However, pooled analyses for tenofovir alafenamide (TAF) effects and comparisons between the 2 regimens are lacking.

DESIGN

In this meta-analysis, pairs of independent reviewers performed multiple database searches from inception to 31 March 2024 and extracted data from cohort studies and randomized controlled trials (RCTs) in highly viremic mothers. The outcomes of interest were the reduction of MTCT and safety in the TDF-treated, TAF-treated, and control groups.

RESULTS

We included 31 studies with 2588 highly viremic mothers receiving TDF, 280 receiving TAF, and 1600 receiving no treatment. Compared to the control, TDF therapy reduced the MTCT rate in infants aged 6-12 months (risk ratio: 0.10, 95% confidence interval [CI] .07-.16). Pairwise meta-analysis between TAF and TDF revealed similar effects on reducing MTCT (risk ratio: 1.09, 95% confidence interval .16-7.61). Network meta-analysis showed equal efficacy of the 2 regimens in reducing MTCT (risk ratio: 1.09, 95% CI .15-7.65). The surface under the cumulative ranking curve revealed TDF as the best regimen compared with TAF (probability ranking: .77 vs .72), while receiving a placebo during pregnancy had the lowest efficacy (probability ranking 0.01). There were no safety concerns for mothers and infants in all regimens.

CONCLUSIONS

Compared to placebo or no treatment, maternal TDF and TAF prophylaxis are equally effective and without safety concerns in reducing MTCT in highly viremic mothers.

Treatment Effects in Randomized and Nonrandomized Studies of Pharmacological Interventions: A Meta-Analysis

Importance

Randomized clinical trials (RCTs) are widely regarded as the methodological benchmark for assessing clinical efficacy and safety of health interventions. There is growing interest in using nonrandomized studies to assess efficacy and safety of new drugs.

Objective

To determine how treatment effects for the same drug compare when evaluated in nonrandomized vs randomized studies.

Data Sources

Meta-analyses published between 2009 and 2018 were identified in MEDLINE via PubMed and the Cochrane Database of Systematic Reviews. Data analysis was conducted from October 2019 to July 2024.

Study Selection

Meta-analyses of pharmacological interventions were eligible for inclusion if both randomized and nonrandomized studies contributed to a single meta-analytic estimate.

Data Extraction and Synthesis

For this meta-analysis using a meta-epidemiological framework, separate summary effect size estimates were calculated for nonrandomized and randomized studies within each meta-analysis using a random-effects model and then these estimates were compared. The reporting of this study followed the Guidelines for Reporting Meta-Epidemiological Methodology Research and relevant portions of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline.

Main Outcome and Measures

The primary outcome was discrepancies in treatment effects obtained from nonrandomized and randomized studies, as measured by the proportion of meta-analyses where the 2 study types disagreed about the direction or magnitude of effect, disagreed beyond chance about the effect size estimate, and the summary ratio of odds ratios (ROR) obtained from nonrandomized vs randomized studies combined across all meta-analyses.

Results

A total of 346 meta-analyses with 2746 studies were included. Statistical conclusions about drug benefits and harms were different for 130 of 346 meta-analyses (37.6%) when focusing solely on either nonrandomized or randomized studies. Disagreements were beyond chance for 54 meta-analyses (15.6%). Across all meta-analyses, there was no strong evidence of consistent differences in treatment effects obtained from nonrandomized vs randomized studies (summary ROR, 0.95; 95% credible interval [CrI], 0.89-1.02). Compared with experimental nonrandomized studies, randomized studies produced on average a 19% smaller treatment effect (ROR, 0.81; 95% CrI, 0.68-0.97). There was increased heterogeneity in effect size estimates obtained from nonrandomized compared with randomized studies.

Conclusions and Relevance

In this meta-analysis of treatment effects of pharmacological interventions obtained from randomized and nonrandomized studies, there was no overall difference in effect size estimates between study types on average, but nonrandomized studies both overestimated and underestimated treatment effects observed in randomized studies and introduced additional uncertainty. These findings suggest that relying on nonrandomized studies as substitutes for RCTs may introduce additional uncertainty about the therapeutic effects of new drugs.

Real-world implementation of a multilevel interventions program to prevent mother-to-child transmission of HBV in China

Reducing hepatitis B virus (HBV) mother-to-child transmission (MTCT) is a fundamental step toward the HBV elimination goal. The multicentred, multilevel SHIELD program aimed to use an intense intervention package to reduce HBV MTCT in China. This study was conducted in diverse health settings across China, encompassing 30,109 pregnant women from 178 hospitals, part of the interim analysis of stage II of the SHIELD program, and 8,642 pregnant women from 160 community-level health facilities in stage III of the SHIELD program. The study found that the overall MTCT rate was 0.23% (39 of 16,908; 95% confidence interval (CI): 0.16-0.32%) in stage II and 0.23% (12 of 5,290; 95% CI: 0.12-0.40%) in stage III. The MTCT rate was lower among participants who were compliant with the interventions (stage II: 0.16% (95% CI: 0.10-0.26%); stage III: 0.03% (95% CI: 0.00-0.19%)) than among those who were noncompliant (3.16% (95% CI: 1.94-4.85%); 1.91% (95% CI: 0.83-3.73%); P < 0.001). Our findings demonstrate that the comprehensive interventions among HBV-infected pregnant women were feasible and effective in dramatically reducing MTCT.

Incidence of mother-to-child transmission of hepatitis B in relation to maternal peripartum antiviral prophylaxis: A systematic review and meta-analysis

INTRODUCTION

Mother-to-child transmission (MTCT) of the hepatitis B virus (HBV) is a serious public health challenge. Estimating HBV MTCT incidence by region under different prophylaxis regimens is critical to understanding the regional disease burden and prioritizing interventions. This study aimed to calculate HBV MTCT incidence under different prophylaxis regimens globally and regionally and identify the HBV DNA threshold for maternal peripartum antiviral prophylaxis.

MATERIAL AND METHODS

This review was registered in advance in PROSPERO (CRD 42019120567). We searched PubMed, Embase, China National Knowledge Infrastructure, ClinicalTrials.gov, and Cochrane Library databases for studies on MTCT in pregnant women with chronic HBV infection from their inception until June 13, 2022. MTCT was defined as hepatitis B surface antigen (HBsAg) or HBV DNA seropositivity in infants aged 6-12 months. We calculated the pooled HBV MTCT incidence using the DerSimonian-Laird random-effects model.

RESULTS

Among 300 studies, 3402 of 63 293 infants had HBV due to MTCT. Without prophylaxis regimens, the pooled HBV MTCT incidence was 31.3%, ranging from 0.0% (95% confidence interval [CI] 0.0%-6.0%; European Region) to 46.1% (95% CI 29.7%-63.0%; Western Pacific Region). Following the introduction of the hepatitis B vaccine, the HBV MTCT incidence decreased from 82.9% to 15.9% in HBeAg-positive women and from 10.3% to 2.3% in HBeAg-negative women. Maternal peripartum antiviral treatment alongside infant immunoprophylaxis further decreased MTCT incidence to 0.3% (95% CI 0.1%-0.5%). Despite infant immunoprophylaxis, the incidences of MTCT at maternal HBV DNA levels of <2.30, 2.00-3.29, 3.00-4.29, 4.00-5.29, 5.00-6.29, 6.00-7.29 and ≥7.00 log₁₀  IU/ml were 0.0% (95% CI 0.0%-0.0%), 0.0% (95% CI 0.0%-0.0%), 0.0% (95% CI 0.0%-0.5%), 0.6% (95% CI 0.0%-2.6%), 1.0% (95% CI 0.0%-3.1%), 4.3% (95% CI 1.8%-7.5%), and 9.6% (95% CI 7.0%-12.5%), respectively.

CONCLUSIONS

HBV MTCT incidence varies across regions. The Western Pacific Region bears the heaviest burden. Peripartum antiviral prophylaxis plus infant immunoprophylaxis is promising for interrupting HBV MTCT. Regarding the HBV DNA threshold for peripartum antiviral prophylaxis, maternal HBV DNA of 4.00 log₁₀  IU/ml or greater seems justified.

Tenofovir disoproxil fumarate therapy to prevent hepatitis B virus vertical transmission-A review of maternal and infant outcomes

Hepatitis B virus (HBV) is a global health problem. Vertical transmission of HBV from HBV surface antigen (HBsAg)-positive mothers to their infants is the most common cause of HBV infection worldwide. The use of passive-active immunoprophylaxis is >90% effective in reducing the risk of vertical transmission, but immunoprophylaxis failure can occur in infants born to mothers with high viraemia. Thus, it is recommended that pregnant women with HBV-DNA level >200 000 IU/ml receive nucleos(t)ide analogue (NA) treatment [i.e. tenofovir disoproxil fumarate (TDF), lamivudine or telbivudine] during third trimester to prevent infant immunoprophylaxis failure. TDF is recommended as the first-line therapy based on available data on efficacy, safety and resistance profile. However, maternal immunological reconstitution following parturition can increase immune-mediated flares to viral antigens that is potentially exacerbated following TDF withdrawal. In this article, we review available data on the efficacy and safety of TDF administration to prevent HBV mother-to-child transmission. We also discuss changes in maternal viral markers [i.e. HBV-DNA, HBV e antigen and HBsAg] and alanine aminotransferase during follow-up post-partum in mothers received NA to prevent HBV vertical transmission.

Antiviral Therapy for Prevention of Perinatal Hepatitis B Virus Transmission Reduces the Incidence of Postpartum Hepatitis Flare

Background: Currently, there are few studies on the effect of prophylactic anti-hepatitis B virus (HBV) therapy (AVT) for mother-to-child transmission during pregnancy on postpartum hepatitis flare (PHF) and the risk factors for postpartum hepatitis flare in women with chronic hepatitis B infection. Aim: To analyze the effect of AVT on the postpartum hepatitis flare and risk factors related to postpartum hepatitis flare. Methods: This study retrospectively enrolled hepatitis B surface antigen (HBsAg)-positive and hepatitis B e antigen (HBeAg)-positive women with HBV DNA ≥ 10⁶  IU/mL. Six hundred fourteen pregnant women were included: 444 in the anti-HBV therapy group (T-G) and 170 in the control group (C-G). To analyze the risk factors, women with alanine aminotransferase (ALT) flare (ALT > 40 U/L) were assigned to the PHF group (PHF-G, n = 355), and all the others were assigned to a non-PHF group (NPHF-G, n = 259). Results: At 6 weeks postpartum, ALT and AST levels were higher, and ALB levels were lower in the C-G than those in T-G (P < 0.05). Also, ALT (at baseline, pregnancy 32nd and 36th, intrapartum), AST (at pregnancy 32nd and 36th week, and intrapartum), HBcAb (at baseline, intrapartum), and HBV DNA (at intrapartum) of PHF-G were significantly higher than those of NPHF-G (P < 0.05). Multivariate analysis showed that ALT (OR = 1.067, P < 0.001) and HBcAb (OR = 1.213, P ≤ 0.001) in pregnant women were risk factors for PHF. The prophylactic anti-HBV for the prevention of perinatal HBV transmission (OR = 0.357, P < 0.001) was the protective factor for PHF. Conclusion: Pregnant women with prophylactic anti-HBV during the third trimester of pregnancy had a lower incidence of postpartum hepatitis flare, especially a lower risk of serious hepatitis flare. ALT and HBcAb in pregnant women were risk factors for PHF. Women infected with HBV should be closely monitored ALT during pregnancy and postpartum.

Antiviral Therapy for a Postpartum Flare in Women with Chronic HBV Infection Shortens the ALT Recovery Time and Reduces Hepatitis Re-Flare Rates within 4 years

Background

Few studies explored whether anti-hepatitis B virus (HBV) therapy should be initiated during postpartum hepatitis flare.

Aim

This study aimed to analyze the effect of anti-HBV therapy on postpartum hepatitis flare and evaluate the prognosis within 4 years postpartum.

Methods

This retrospective study enrolled hepatitis B surface antigen (HBsAg)-positive and hepatitis B e antigen (HBeAg)-positive pregnant women with HBV DNA ≥ 106 IU/mL. A total of 152 pregnant women were included: 103 in the prophylactic anti-HBV therapy group (PT-G) and 49 in the non-prophylactic anti-HBV therapy group (NPT-G). The women with a postpartum flare were assigned to the anti-HBV therapy group (AT-G) and non-anti-HBV therapy group (NAT-G) to analyze the effect of postpartum anti-HBV therapy on hepatitis flare. Virological and biochemical parameters were assessed.

Results

Taking postpartum 12 weeks as the cutoff point, the ALT recovered time for postpartum flare women is shorter in AT-G (n = 16, 42.1%) or PT-G (n = 23, 34.8%) than in NAT-G (n = 14, 23.0%; x 2 = 4.067, P=0.044) or NPT-G (n = 4, 11.1%; x 2 = 5.579, P=0.018). Taking postpartum 26 weeks as the cutoff point, the ALT recovered time is shorter in AT-G (n = 35, 57.3%) or PT-G (n = 44, 66.7%) than in NAT-G (n = 32, 84.2%; x 2 = 7.707, P=0.006) or NPT-G (n = 16, 44.4%; x 2 = 4.749, P=0.029). Postpartum flare recovery time was positively correlated with HBV DNA level at delivery [r = 0.223, P=0.025, 95%CI (0.022～0.41)]. The hepatitis re-flare rates within postpartum 4 years in AT-G (n = 3, 9.68%) is lower than that in NAT-G (n = 24, 45.4%; x 2 = 14.003, P ≤ 0.001). The HBeAg, HBsAg, HBV DNA, and ALT level at postpartum 4 years in AT-G were lower than that in NAT-G (P < 0.001).

Conclusion

Anti-HBV therapy for postpartum hepatitis flare of women with chronic HBV could shorten the ALT recovery time and reduce hepatitis re-flare rates within 4 years of postpartum.

Long-term safety of infants from mothers with chronic hepatitis B treated with tenofovir disoproxil in China

OBJECTIVE

The physical and neuromental development of infants remains uncertain after fetal exposure to tenofovir disoproxil fumarate (TDF) for the prevention of mother-to-child transmission of HBV. We aimed to investigate the safety of TDF therapy during the third trimester of pregnancy.

DESIGN

Infants from a previous randomised controlled trial were recruited for our long-term follow-up (LTFU) study. Mothers with chronic hepatitis B were randomised to receive TDF therapy or no treatment during the third trimester. Infants' physical growth or malformation, bone mineral density (BMD) and neurodevelopment, as assessed using Bayley-III assessment, were examined at 192 weeks of age.

RESULTS

Of 180 eligible infants, 176/180 (98%) were enrolled and 145/176 (82%) completed the LTFU (control group: 75; TDF-treated group: 70). In the TDF-treated group, the mean duration of fetal exposure to TDF was 8.57±0.53 weeks. Congenital malformation rates were similar between the two groups at week 192. The mean body weight of boys in the control and TDF-treated groups was significantly higher (19.84±3.46 kg vs. 18.47±2.34 kg; p=0.03) and within the normal range (18.48±2.35 kg vs. 17.80±2.50 kg; p=0.07), respectively, when compared with the national standard. Other prespecified outcomes (head circumference, height, BMD, and cognitive, motor, social-emotional, and adaptive behaviour measurements) were all comparable between the groups.

CONCLUSION

Infants with fetal exposure to TDF had normal physical growth, BMD and neurodevelopment at week 192. Our findings provide evidence on the long-term safety of infants after fetal exposure to maternal TDF therapy for preventing hepatitis B transmission.

TRIAL REGISTRATION NUMBER

NCT01488526.

Hepatitis B virus genotype is an independent prognostic factor of telbivudine and tenofovir treatment in hepatitis B surface antigen-positive pregnant women

To investigate whether HBV genotype influences the effect of tenofovir and telbivudine on HBV DNA and RNA levels in HBsAg-positive pregnant women. This was a retrospective study of 74 HBsAg-positive pregnant women in Guizhou of China. All patients were treated with telbivudine or tenofovir from 12 weeks of pregnancy and HBV infection to the date of delivery. Blood samples were collected at 12-24, 28-32, and 36-40 weeks of pregnancy for the measurement of genotype, HBsAg, hepatitis B e antigen (HBeAg), HBV DNA, HBV RNA, and liver function, including alanine transaminase, aspartate transaminase, total bilirubin, total bile acids, cholinesterase, alkaline phosphatase (ALP), and gamma-glutamyl transferase. All women with HBsAg were followed up. The HBV genotype was B in 64.9% and C in 35.1%. There were 37 patients of telbivudine and tenofovir group respectively. The telbivudine and tenofovir groups showed no differences in demographic and clinical characteristics, including liver function tests, HBsAg, HBeAg, log10(HBV DNA), and log10(HBV RNA). Compared with baseline (12-24 weeks), telbivudine group showed a significant increase in ALP and significant reductions in HBsAg, HBeAg, log10(HBV DNA), and log10(HBV RNA) at 36-40 weeks (p < .05). Tenofovir group exhibited a significant increase in ALP and significant reductions in HBeAg, log10(HBV DNA), and log10(HBV RNA) at 36-40 weeks, compared with baseline (p < .05). HBV genotype (B vs. C) was independently associated with HBV DNA change after therapy (p = .005). In telbivudine group, log10 (HBV DNA) increased from 3.38 (2.00-7.30) to 7.43 (4.68-8.70). In tenofovir group, log10 (HBV DNA) decreased from 7.52 (3.32-8.70) to 2.98 (2.00-5.01). HBV genotype was independently associated with HBV DNA change response to telbivudine or tenofovir in pregnant women with hepatitis B. These findings might be helpful for risk assessment regarding vertical transmission of HBV in HBeAg-positive mothers treated with nucleos(t)ide analogues.

The impact of the timely birth dose vaccine on the global elimination of hepatitis B

In 2016 the World Health Organization set the goal of eliminating hepatitis B globally by 2030. Horizontal transmission has been greatly reduced in most countries by scaling up coverage of the infant HBV vaccine series, and vertical transmission is therefore becoming increasingly dominant. Here we show that scaling up timely hepatitis B birth dose vaccination to 90% of new-borns in 110 low- and middle-income countries by 2030 could prevent 710,000 (580,000 to 890,000) deaths in the 2020 to 2030 birth cohorts compared to status quo, with the greatest benefits in Africa. Maintaining this could lead to elimination by 2030 in the Americas, but not before 2059 in Africa. Drops in coverage due to disruptions in 2020 may lead to 15,000 additional deaths, mostly in South-East Asia and the Western Pacific. Delays in planned scale-up could lead to an additional 580,000 deaths globally in the 2020 to 2030 birth cohorts.

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.

Hepatitis B Virus Infection in Pregnancy: An Update on Evidence-Based Management

Importance

Vertical hepatitis B virus (HBV) transmission is the important route of chronic HBV infection. Although infant immunoprophylaxis is effective, a significant number of infants still become infected, most are associated with intrauterine infection. New evidences support intrauterine treatment in cases of high risk.

Objective

The aim of this study was to review the current evidences and recommendations for management of HBV infection in pregnancy.

Evidence Acquisition

Original research articles, review articles, and guidelines were reviewed.

Results

The management can be summarized as follows: (1) all pregnant women should be screened for hepatitis B surface antigen (HBsAg) and antibody to HBsAg. High-risk HBsAg-negative pregnant women without immunity should be vaccinated during pregnancy. (2) HBsAg-positive pregnant women should undergo further workup for liver status and indicative factors for immunoprophylaxis failure. (3) Pregnant women should be treated with HBV DNA levels greater than 200,000 IU/mL or 6 log copies/mL. (4) Antiviral drug should be started around 28 to 32 weeks. The first-line drug is tenofovir disoproxil fumarate. (5) Delivery route should be chosen based only on obstetric indications. (6) Breastfeeding is not contraindicated because it does not increase the risk of transmission in neonates with HBV vaccine and immunoglobulin administration. (7) Neonates born to HBsAg-positive mothers should receive HBV vaccine and immunoglobulin after birth as soon as possible. (8) Follow-up of the mothers and neonates is important. Beware of hepatitis flare after birth and after antiretroviral drug discontinuation; alanine transaminase assessment every 1 to 3 months until 6 months is suggested. Also, the schedule of infant vaccination and follow-up of serologic testing at 9 to 12 months old is needed.

Guideline No. 409: Intrauterine Fetal Diagnostic Testing in Women with Chronic Viral Infections

OBJECTIVE

This revised guideline provides updated information for the care of women with chronic viral infections who require intrauterine fetal diagnostic testing.

TARGET POPULATION

Women with chronic viral infections who are pregnant or planning a pregnancy.

OPTIONS

Non-invasive screening tests for diagnosis: maternal serum placental analytes with or without nuchal translucency, sonography, maternal serum cell-free placental DNA; and intrauterine fetal diagnostic testing: amniocentesis, chorionic villus sampling, cordocentesis.

OUTCOMES

The recommendations in this guideline have the potential to decrease or eliminate morbidity and mortality in women with chronic viral infections and their infants, which is associated with significant health and economic outcomes.

EVIDENCE

Published literature was retrieved through searches of PubMed, guidelines of national societies (Society of Obstetricians and Gynaecologists of Canada, American College of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine, other international societies), and the Cochrane Library using appropriate controlled vocabulary (amniocentesis, chorionic villus sampling, cordocentesis, procedure pregnancy loss risk, viral vertical transmission, fetal and neonatal infection) and keywords (maternal infection or exposure, hepatitis B, hepatitis C, human immunodeficiency virus). Results were restricted to systematic reviews, randomized controlled trials or controlled clinical trials (if available), and observational case-control studies or case series from 2012 to 2019 published in English or French. Studies from 1966 to 2002 were previously reviewed in the SOGC guideline No. 123: Amniocentesis and Women with Hepatitis B, Hepatitis C, or Human Immunodeficiency Virus, and those from 2002 to 2012 were previously reviewed in the SOGC guideline No. 309: Prenatal Invasive Procedures in Women With Hepatitis B, Hepatitis C, and/or Human Immunodeficiency Virus Infections. Updated literature searches were completed regularly through August 2019 and were incorporated into this guideline.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

The intended users are maternity care providers and women with chronic viral infections. This guideline provides information to educate and counsel these women, and to offer them reproductive options. RECOMMENDATIONS (GRADE RATINGS IN PARENTHESES).

Benefits and Risks of Antiviral Treatment during Pregnancy in Patients with Chronic Hepatitis B

Hepatitis B virus (HBV) is a main cause of chronic liver disease worldwide and can lead to severe liver diseases. The World Health Organization has planned to eliminate viral hepatitis, including hepatitis caused by HBV and hepatitis C virus, by 2030. As mother-to-child transmission (MTCT) of HBV is a main cause of chronic HBV infection, MTCT prevention is the main target to reduce the risk of chronic HBV infection and eliminate the disease. Recent clinical trials and meta-analyses found that antiviral therapy could prevent MTCT effectively in mothers with ≥200,000 IU/mL of HBV DNA, in combination with serial vaccination and hepatitis B immune globulin administration in infants. Despite the preventive role of antivirals for MTCT of HBV, there are several concerns regarding antiviral therapy with respect to the safety of the mother and fetus during pregnancy. This review summarizes the benefits and risks of antiviral treatment during pregnancy in women with chronic HBV infection.

Challenges in Formulation and Implementation of Hepatitis B Elimination Programs

Nearly 257 million individuals have contracted hepatitis B infection around the world. However, only 10% of them know about their illness. Mother to child transmission, nosocomial spread, and sexual transmission are the major etiological factors. Finding the missing millions is a global issue. Hepatitis B care is more difficult compared to hepatitis C as not all patients require treatment and the selection of patients is not straightforward. To eliminate hepatitis B infection, the program should screen pregnant women and start antiviral therapy from the 28th week of pregnancy if hepatitis B virus (HBV) DNA≥ 200,000 IU/mL or hepatitis B e-antigen (HBeAg) reactive. Prevention of perinatal infection, birth dose and neonatal vaccination, post-vaccination monitoring of high-risk groups, catch-up vaccination, and registration of the carriers should be an integral part of the program. Continuum of care is important when planning the elimination program from addressing the risk factors, testing, and referral for treatment. The program should integrate test and treat hepatitis services with existing local health care services. There is a need to create the right environment, raise awareness, remove stigma, and increase screening of those at risk and manage those who require treatment. A national policy should be prepared for capacity building, fund allocation, and implementation strategies. Micro-elimination strategies should boost national elimination effects. Guidelines to diagnose and treat patients with hepatitis B should be simplified. Surveillance should be done to monitor progress, and determine the impact of the elimination program on incidence and mortality, and services.

Effect of different antiviral regimens on the viral loads in pregnant women with hepatitis B virus infection and their impact on mother-to-child transmission

AIM

This study aimed to explore the benefits of different antiviral regimens in pregnant women with hepatitis B virus (HBV) infection in an attempt to provide scientific reference for clinically relevant interventions.

METHODS

The study cohort comprised 64 pregnant women with HBV infection who presented to our hospital from May 2018 to July 2020. The women were grouped according to the treatment administered: a control group consisting of 32 pregnant women who received routine intervention and an observation group consisting of 32 pregnant women who received routine intervention plus tenofovir disoproxil fumarate (TDF) tablets. The two groups were compared in terms of liver function; HBV load (HBV DNA); neonatal characteristics (hepatitis B surface antigen and HBV DNA positivity); levels of interleukin (IL)-2, IL-4, and IL-6; neonatal growth and development; Apgar scores; incidence of adverse events; and incidence of maternal adverse effects during treatment.

RESULTS

The observation group had lower levels of alanine aminotransferase, glutamic acid aminotransferase, IL-4, IL-6, and HBV DNA and higher levels of IL-2 than the control group after 1 month of treatment (p < 0.05). There was no significant difference in the incidence of adverse events between the two groups (p > 0.05).

CONCLUSION

The administration of TDF tablets significantly reduced the HBV DNA levels and did not increase the physiological burden or adverse effects in pregnant women with HBV infection.

Tenofovir disoproxil fumarate for prevention of mother-to-child transmission of hepatitis B virus: A systematic review and meta-analysis of randomised control trials

Hepatitis B virus (HBV) infection caused by mother-to-child transmission (MTCT) continues to pose challenges to global health. This study aimed to assess the efficacy and safety of tenofovir disoproxil fumarate (TDF) for preventing HBV MTCT. PubMed and the Cochrane Central Register of Controlled Trials were searched through August 2020. Randomised controlled trials (RCTs) were selected that evaluated the efficacy and safety of TDF for preventing MTCT of HBV compared with the standard of care, placebo or other HBV therapies. The primary outcomes were HBV MTCT rate and maternal HBV DNA level. Secondary outcomes were infant and maternal safety outcomes. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines, and prospectively registered on PROSPERO (CRD42020186275). Of 240 citations, three RCTs that involved 651 participants were included. The pooled result showed that TDF can reduce the risk of HBV MTCT after 6 months postpartum by 80% (risk ratio [RR] 0.2, 95% confidence interval [CI 0.06-0.7], n = 584) with low heterogeneity (I²  = 0%). TDF demonstrated HBV DNA suppression at delivery, though there was heterogeneity among individual studies (RR 0.13, 95% CI [0.08-0.20] and (RR 0.36, 95% CI [0.27-0.49]). Maternal and infant safety outcomes were comparable among treated and untreated mothers and infants born to them. The quality of evidence varied from high to very low. There is evidence that TDF effectively interrupted MTCT of HBV and suppressed HBV DNA level. Available studies on safety are very limited and heterogeneous, emphasising the need for additional RCTs with complete safety indicators.

Role of tenofovir disoproxil fumarate in prevention of perinatal transmission of hepatitis B virus from mother to child: a systematic review and meta-analysis

BACKGROUND/AIMS

To prevent the perinatal transmission of hepatitis B virus (HBV) from mother to child, administration of an antiviral agent during pregnancy has been attempted in women who are either hepatitis B e antigen positive or have a high viral load. In this systematic review and meta-analysis with randomized controlled trials, we analyzed the efficacy and safety of tenofovir disoproxil fumarate (TDF) in preventing the perinatal transmission of HBV in pregnant women who have high HBV DNA titers.

METHODS

Multiple comprehensive databases (PubMed, EMBASE, and Cochrane databases) were searched for studies evaluating the efficacy of TDF for the prevention of perinatal transmission of HBV.

RESULTS

Two studies (one open label study and one double blind study) were included and analyzed. Intention-to-treat analysis (527 pregnancies) showed that the preventive effect of TDF was not significant (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.13 to 2.17; p = 0.38, I2 = 81%). However, the per-protocol analysis showed that TDF significantly reduced perinatal transmission (OR, 0.10; 95% CI, 0.01 to 0.77; p = 0.03, I2 = 0%). There was no significant difference between the TDF group and the control group with respect to maternal and fetal safety outcomes.

CONCLUSION

In pregnant women who have high HBV DNA titers, TDF can reduce the perinatal transmission from mother to child without significant adverse events.

Directive clinique no 409 : Tests diagnostiques fœtaux intra-utérins en cas d'infection virale chronique maternelle

OBJECTIF

La présente directive clinique révisée met à jour les renseignements sur la prestation de soins aux femmes atteintes d'une infection virale chronique devant se soumettre à un test diagnostique fœtal intra-utérin.

POPULATION CIBLE

Femmes atteintes d'une infection virale chronique qui sont enceintes ou prévoient le devenir.

OPTIONS

Tests de dépistage non invasifs à des fins diagnostiques : marqueurs placentaires sériques maternels avec ou sans mesure de la clarté nucale, échographie, ADN fœtal libre circulant dans le sang maternel; et tests diagnostiques fœtaux intra-utérins : amniocentèse, biopsie choriale (choriocentèse), cordocentèse.

ISSUES

Les recommandations de la présente directive clinique pourraient réduire ou éliminer la morbi-mortalité chez les femmes atteintes d'une infection virale chronique et leurs nourrissons, ce qui est associé à d'importantes conséquences sur les plans de la santé et de l'économie. DONNéES PROBANTES: La littérature publiée a été recueillie au moyen de recherches dans les bases de données PubMed et Cochrane Library ainsi que dans les directives cliniques de sociétés médicales nationales et internationales (Société des obstétriciens et gynécologues du Canada, American College of Obstetricians and Gynecologists, Society for Maternal-Fetal Medicine et d'autres sociétés internationales) en utilisant un vocabulaire (amniocentesis, chorionic villus sampling, cordocentesis, procedure pregnancy loss risk, viral vertical transmission, fetal and neonatal infection) et des mots clés (maternal infection or exposure, hepatitis B, hepatitis C, human immunodeficiency virus) contrôlés et appropriés. Les résultats retenus se limitent aux revues systématiques, aux essais cliniques randomisés ou aux essais cliniques comparatifs (si disponibles) et aux études cas-témoins observationnelles ou études de série de cas publiées entre 2012 et 2019 en anglais ou en français. Les études publiées entre 1966 et 2002 ont déjà été examinées dans la directive clinique de la SOGC n^o 123, L'amniocentèse chez les femmes infectées par l'hépatite B, l'hépatite C ou le virus de l'immunodéficience humaine; les études publiées entre 2002 et 2012 ont quant à elles été examinées dans la directive clinique de la SOGC n^o 309, Interventions effractives prénatales chez les femmes qui présentent des infections par le virus de l'hépatite B, le virus de l'hépatite C et/ou le virus de l'immunodéficience humaine. De nouvelles recherches ont été effectuées dans la littérature jusqu'en août 2019, puis ont été intégrées à la présente directive clinique. MéTHODES DE VALIDATION: L'auteur a évalué la qualité des données probantes et la solidité des recommandations au moyen du cadre méthodologique GRADE (Grading of Recommendations Assessment, Development, and Evaluation). Consulter l'annexe A en ligne (le tableau A1 pour les définitions et le tableau A2 pour les interprétations des recommandations fortes et faibles). PUBLIC VISé: Les utilisateurs prévus sont des fournisseurs de soins de maternité et les femmes atteintes d'une infection virale chronique. Cette directive fournit des renseignements pour renseigner et conseiller ces femmes et leur offrir des options de procréation. RECOMMENDATIONS (GRADE RATINGS IN PARENTHESES).

Progress towards elimination of mother-to-child transmission of hepatitis B virus infection in China: a modelling analysis

Objective

To determine the projected burden of hepatitis B virus (HBV) in China, the intervention strategies that can eliminate mother-to-child transmission (MTCT) by 2030 or earlier and the measurable parameters that can be used to monitor progress towards this target.

Methods

We developed a dynamic, sex- and age-stratified model of the HBV epidemic in China, calibrated using hepatitis B surface antigen (HBsAg) and e antigen (HBeAg) prevalence data from sequential national serosurveys (1979-2014) and the numbers of HBV-related cancer deaths (2012). We determined whether China can achieve elimination of MTCT of HBV by 2030 under current prevention interventions. We modelled various intervention scenarios to represent different coverage levels of birth-dose HBV vaccination, hepatitis B immunoglobulin to newborns of HBsAg-positive mothers and antiviral therapy (tenofovir) to HBeAg-positive pregnant women.

Findings

We project that, if current levels of prevention interventions are maintained, China will achieve the elimination target by 2029. By modelling various intervention scenarios, we found that this can be brought forward to 2025 by increasing coverage of birth-dose vaccination, or to 2024 by the administration of tenofovir to HBeAg-positive pregnant women. We found that achievement of the target by 2025 would be predicted by a measurement of less than 2% MTCT in 2020.

Conclusion

Our results highlight how high-quality national data can be combined with modelling in monitoring the elimination of MTCT of HBV. By demonstrating the impact of increased interventions on target achievement dates, we anticipate that other high-burden countries will be motivated to strengthen HBV prevention policies.

Pharmacokinetics of oral tenofovir disoproxil fumarate in pregnancy and lactation: a systematic review

BACKGROUND

Tenofovir disoproxil fumarate (TDF), the oral prodrug of tenofovir (TFV), is advocated in pregnancy for prevention of mother-to-child transmission (PMCT) with failure of hepatitis B immunoglobulin and vaccination. The pharmacokinetics of TDF monotherapy for PMCT-HBV is important if deployment is to emulate the success of multiple antiretrovirals (ARVs) for PMCT-HIV in resource-constrained settings.

METHODS

This systematic review followed a protocol and is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA) guidelines. We included studies that enrolled pregnant women who received oral TDF therapy as monotherapy or in combination with other ARVs: irrespective of the reason for receiving the drug (for example, HIV, HBV or pre-exposure prophylaxis); and reported pharmacokinetics.

RESULTS

The area under the concentration-time curve (AUC), maximum plasma concentrations (C_max) and last measurable plasma concentration (C_last) of TFV were decreased in the second and third trimester compared with first trimester or post-partum. In none of the manuscripts was the non-pregnant HBV threshold of C_max of 300 ng/ml reached, but the 50% effective concentration (EC₅₀) of TFV is lower for treatment of HBV compared with HIV. The TFV concentration in breastfed infants was 0.03% of the recommended infant dose.

CONCLUSIONS

Most knowledge of pharmacokinetics of TFV in pregnancy results from studies on HIV involving multiple ARVs. Increased TFV clearance occurred in the second and third trimester when optimal TFV concentrations are required to maximize suppression of HBV in the window before birth. Dose or duration adjustments will be better conceptualized with concurrent analysis of the pharmacokinetics of TFV monotherapy and hepatitis B pharmacodynamics in pregnancy.

Identifying gaps across the cascade of care for the prevention of HBV mother-to-child transmission in Burkina Faso: Findings from the real world

BACKGROUND

Prevention of mother-to-child transmission (PMTCT) is a challenge for controlling the hepatitis B epidemic. In Sub-Saharan countries, pilot interventions including the screening of pregnant women for HBsAg, implementation of anti-HBV therapy and infant immunization within 24 hours of life are initiated and need to be evaluated. This pilot study aimed to describe the cascade of care for hepatitis B PMTCT in a real life situation, and to identify sociodemographic factors associated with adequate management of pregnant women and infants.

METHOD

The study was conducted from October 1st, 2014 to February 28th, 2016 in the antenatal clinics (ANCV) of Baskuy district which comprises nine first-level public health centres. Univariate and multivariate logistic regression analysis were used to identify sociodemographic factors associated with the likelihood of retention in the cohort, HBV DNA testing, birth dose delivery and HBsAg testing of the children at 6 months of age; P ˂ .05 was selected as cut off for significance.

RESULTS

In this prospective cohort study, of 5200 pregnant women consulting for the antenatal visit, 2261 (43.5%) were proposed pre-test counselling and HBsAg screening and 2220 (98.2%) have agreed to screening. Among 1580 (71.2%) women that came back for the post-counselling interview, 75 were positive for HBsAg (4.8%), 73 (97.3% of the women provided HBsAg result) consented to medical consultation with hepatogastroenterologists and 53 (72.6%); performed the HBV DNA testing. Forty-seven out of 60 (78.3%; 65.8-87.9) children born alive were immunized for HBV within 24 hours of life. Retention in care was associated with the level of education of the infant's father, secondary school or higher was associated with a better retention in care of the women (OR: 6.6; P = .03).

CONCLUSION

Our study shows large gaps in HBV PMTCT. Resources for hepatitis B screening, care and prevention including universal access to the vaccine birth dose should be allocated to reduce infection in HBV exposed infants born in Burkina Faso.

Impact of Hepatitis B Virus Genetic Variation, Integration, and Lymphotropism in Antiviral Treatment and Oncogenesis

Chronic Hepatitis B Virus (HBV) infection poses a significant global health burden. Although, effective treatment and vaccinations against HBV are available, challenges still exist, particularly in the development of curative therapies. The dynamic nature and unique features of HBV such as viral variants, integration of HBV DNA into host chromosomes, and extrahepatic reservoirs are considerations towards understanding the virus biology and developing improved anti-HBV treatments. In this review, we highlight the importance of these viral characteristics in the context of treatment and oncogenesis. Viral genotype and genetic variants can serve as important predictive factors for therapeutic response and outcomes in addition to oncogenic risk. HBV integration, particularly in coding genes, is implicated in the development of hepatocellular carcinoma. Furthermore, we will discuss emerging research that has identified various HBV nucleic acids and infection markers within extrahepatic sites (lymphoid cells). Intriguingly, the presence of hepatocellular carcinoma (HCC)-associated HBV variants and viral integration within the lymphoid cells may contribute towards the development of extrahepatic malignancies. Improved understanding of these HBV characteristics will enhance the development of a cure for chronic HBV infection.

Tenofovir for prevention of mother to child transmission of hepatitis B in migrant women in a resource-limited setting on the Thailand-Myanmar border: a commentary on challenges of implementation

BACKGROUND

The aim of this manuscript is to highlight challenges in the implementation of maternal tenofovir disoproxil fumarate (tenofovir) for prevention of mother to child transmission (PMTCT) of hepatitis B virus (HBV) in resource limited setting. Current preventive strategies in resource-limited settings fail mainly due to prohibitive costs of hepatitis B immunoglobulin (HBIG) and a high proportion of homebirths, meaning both HBIG and hepatitis B birth dose vaccine are not given. A new strategy for PMTCT without the necessity of HBIG, could be daily tenofovir commenced early in gestation. Implementation challenges to early tenofovir for PMTCT can provide insight to elimination strategies of HBV as the burden of disease is high in resource-limited settings.

METHODS

Challenges encountered during implementation of a study of tenofovir for PMTCT before 20 weeks gestation in rural and resource-limited areas on the Thailand-Myanmar border were identified informally from trial study logbooks and formally from comments from patients and staff at monthly visits. ClinicalTrials.gov Identifier: NCT02995005.

MAIN BODY

During implementation 171 pregnant women were hepatitis B surface antigen (HBsAg) positive by point of-care test over 19 months (May-2018 until Dec-2019). In this resource-limited setting where historically no clinic has provided tenofovir for PMTCT of HBV, information provided by staff resulted in a high uptake of study screening (95.5% (84/88) when offered to pregnant women. False positive point-of-care rapid tests hinder a test and treat policy for HBV and development of improved rapid tests that include HBeAg and/or HBV DNA would increase efficiency. Integrated care of HBV to antenatal care, transport assistance and local agreements to facilitate access, could increase healthcare at this critical stage of the life course. As safe storage of medication in households in resource-limited setting may not be ideal, interactive counseling about this must be a routine part of care.

CONCLUSION

Despite challenges, results from the study to date suggest tenofovir can be offered to HBV-infected women in resource-limited settings before 20 weeks gestation with a high uptake of screening, high drug accountability and follow-up, with provision of transportation support. This commentary has highlighted practical implementation issues with suggestions for strategies that support the objective of PMTCT and the World Health Organization goal of HBV elimination by 2030.

Evidence for Use of Tenofovir in Pregnancy to Prevent Perinatal Transmission of Hepatitis B Infection

Perinatal transmission of hepatitis B virus continues to be a serious global public health concern. Transmission failures are related to high maternal viremia. Several antiviral therapies reduce maternal viremia around the time of delivery and decrease maternal-to-child-transmission. This chapter is a review of current studies that, ultimately, have provided strong evidence for the efficacy and safety of 3 antiviral drugs in pregnancy-lamivudine, telbivudine and tenofovir. The latter drug is the particular focus of this chapter which will show that tenofovir is the preferred antiviral therapy in pregnant women because of its potency, safety profile, and low risk of resistance.

Comparison of clinical practice guidelines for the management of chronic hepatitis B: When to start, when to change, and when to stop

Clinical practice guidelines are important for guiding the management of specific diseases by medical practitioners, trainees, and nurses. In some cases, the guidelines are utilized as a reference for health policymakers in controlling diseases with a large public impact. With this in mind, practice guidelines for the management of chronic hepatitis B (CHB) have been developed in the United States, Europe, and Asian-Pacific regions to suggest the best-fit recommendations for each social and medical circumstance. Recently, the Korean Association for the Study of the Liver published a revised version of its clinical practice guidelines for the management of CHB. The guidelines included updated information based on newly available antiviral agents, the most recent opinion on the initiation and cessation of treatment, and updates for the management of drug resistance, partial virological response, and side effects. Additionally, CHB management in specific situations was comprehensively revised. This review compares the similarities and differences among the various practice guidelines to identify unmet needs and improve future recommendations.

Efficacy and safety of antiviral prophylaxis during pregnancy to prevent mother-to-child transmission of hepatitis B virus: a systematic review and meta-analysis

BACKGROUND

To eliminate mother-to-child transmission (MTCT) of hepatitis B virus (HBV), peripartum antiviral prophylaxis might be required for pregnant women infected with HBV who have a high risk of MTCT despite infant immunoprophylaxis. We aimed to determine the efficacy and safety of peripartum antiviral prophylaxis to inform the 2020 WHO guidelines.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, Scopus, CENTRAL, CNKI, and Wanfang for randomised controlled trials and non-randomised studies of peripartum antiviral prophylaxis versus placebo or no prophylaxis, with no language restriction, published from database inception until March 28, 2019. We used search terms covering HBV, antiviral therapy, and pregnancy. We included studies that enrolled pregnant women with chronic infection with HBV who received antiviral prophylaxis anytime during pregnancy; that included any of the following antivirals: adefovir, emtricitabine, entecavir, lamivudine, telbivudine, tenofovir alafenamide fumarate, and tenofovir disoproxil fumarate; and that reported the following outcomes: MTCT, indicated by infant HBsAg positivity or HBV DNA positivity, or both, at age 6-12 months, and any infant or maternal adverse events. Two reviewers independently extracted data. Our primary endpoint was MTCT based on infant HBsAg positivity. We assessed pooled odds ratios (ORs) of the efficacy of peripartum antiviral prophylaxis to reduce the risk of MTCT. We assessed safety of prophylaxis by pooling risk differences. The protocol for the systematic review was pre-registered in PROSPERO, CRD42019134614.

FINDINGS

Of 7463 articles identified, 595 articles were eligible for full-text review and 129 studies (in 157 articles) were included. The following antivirals were assessed in the meta-analysis: tenofovir disoproxil fumarate 300 mg (19 studies, with 1092 mothers and 1072 infants), lamivudine 100-150 mg (40 studies, with 2080 mothers and 2007 infants), and telbivudine 600 mg (83 studies, with 6036 mothers and 5971 infants). The pooled ORs for randomised controlled trials were similar, at 0·10 (95% CI 0·03-0·35) for tenofovir disoproxil fumarate, 0·16 (0·10-0·26) for lamivudine, and 0·14 (0·09-0·21) for telbivudine. The pooled ORs in non-randomised studies were 0·17 (0·10-0·29) for tenofovir disoproxil fumarate, 0·17 (0·12-0·24) for lamivudine, and 0·09 (0·06-0·12) for telbivudine. We found no increased risk of any infant or maternal safety outcomes after peripartum antiviral prophylaxis.

INTERPRETATION

Peripartum antiviral prophylaxis is highly effective at reducing the risk of HBV MTCT. Our findings support the 2020 WHO recommendation of administering antivirals during pregnancy, specifically tenofovir disoproxil fumarate, for the prevention of HBV MTCT.

FUNDING

World Health Organization.

Accelerating progress towards the elimination of mother-to-child transmission of HIV: a narrative review

INTRODUCTION

Findings from biomedical, behavioural and implementation studies provide a rich foundation to guide programmatic efforts for the prevention of mother-to-child HIV transmission (PMTCT).

METHODS

We summarized the current evidence base to support policy makers, programme managers, funding agencies and other stakeholders in designing and optimizing PMTCT programmes. We searched the scientific literature for PMTCT interventions in the era of universal antiretroviral therapy for pregnant and breastfeeding women (i.e. 2013 onward). Where evidence was sparse, relevant studies from the general HIV treatment literature or from prior eras of PMTCT programme implementation were also considered. Studies were organized into six categories: HIV prevention services for women, timely access to HIV testing, timely access to ART, programme retention and adherence support, timely engagement in antenatal care and services for infants at highest risk of HIV acquisition. These were mapped to specific missed opportunities identified by the UNAIDS Spectrum model and embedded in UNICEF operational guidance to optimize PMTCT services.

RESULTS AND DISCUSSION

From May to November 2019, we identified numerous promising, evidence-based strategies that, properly tailored and adopted, could contribute to population reductions in vertical HIV transmission. These spanned the HIV and maternal and child health literature, emphasizing the importance of continued alignment and integration of services. We observed overlap between several intervention domains, suggesting potential for synergies and increased downstream impact. Common themes included integration of facility-based healthcare; decentralization of health services from facilities to communities; and engagement of partners, peers and lay workers for social support. Approaches to ensure early HIV diagnosis and treatment prior to pregnancy would strengthen care across the maternal lifespan and should be promoted in the context of PMTCT.

CONCLUSIONS

A wide range of effective strategies exist to improve PMTCT access, uptake and retention. Programmes should carefully consider, prioritize and plan those that are most appropriate for the local setting and best address existing gaps in PMTCT health services.

Mother-to-child transmission of hepatitis B: What more needs to be done to eliminate it around the world?

Mother-to-child transmission (MTCT) of hepatitis B virus (HBV) is a key component of the hepatitis B burden worldwide. Despite its efficacy to prevent HBV transmission, infant vaccination is not enough to control HBV MTCT. Additional efforts are urgently needed to evaluate and scale-up preventive strategies especially in endemic countries, which are most affected. This review highlights the efficacy and barriers of the currently validated measures for the prevention of HBV MTCT and proposes alternatives adapted to resource-limited settings to eventually achieve HBV elimination worldwide.

Tenofovir prophylaxis for preventing mother-to-child hepatitis B virus transmission in China: A cost-effectiveness analysis

OBJECTIVES

This study aimed to evaluate whether tenofovir prophylaxis for mothers with high viral loads in late pregnancy is a cost-effective way to prevent mother-to-child hepatitis B virus (HBV) transmission in China.

METHODS

A decision tree Markov model was constructed for a cohort of infants born to HBV surface antigen-positive mothers in China, 2016. The expected cost and effectiveness were compared between the current active-passive immunoprophylaxis strategy and the tenofovir prophylaxis strategy, and the incremental cost-effectiveness ratio was calculated. One-way and multi-way probabilistic sensitivity analyses were performed.

RESULTS

For 100,000 babies born to mothers positive for hepatitis B surface antigen, tenofovir prophylaxis strategy will prevent 2213 perinatal HBV infections and will gain 931 quality-adjusted life years when compared with the current active-passive immunoprophylaxis strategy. The incremental cost-effectiveness ratio was ￥59,973 ($9087) per quality-adjusted life years gained. This result was robust over a wide range of assumptions.

CONCLUSIONS

Tenofovir prophylaxis for mothers with high viral loads in late pregnancy was found to be more cost-effective than the current active-passive immunoprophylaxis alone. Embedding tenofovir prophylaxis for mothers with high virus loads into the present hepatitis B prevention strategies should be considered to further prevent mother-to-child hepatitis B transmission in China.

Hepatitis B - Vertical transmission and the prevention of mother-to-child transmission

Hepatitis B virus (HBV) infection is the commonest cause of chronic hepatitis, with an estimated global prevalence of 3.5%, and which leads to significant morbidity and mortality. Mother-to-child transmission (MTCT) during pregnancy is the leading form of transmission in endemic populations, and its interruption is thus crucial as the initial step in the elimination of HBV infection, notwithstanding the availability of potent antiviral medications. The risk of MTCT is dramatically reduced by timely neonatal HBV vaccination and the administration of hepatitis B immunoglobulin after birth in high-risk infants. Maternal HBV DNA quantification during pregnancy allows the assessment of the risk of newborn immunoprophylaxis failure (IF). Maternal antiviral treatment in highly viremic women can reduce the risk of IF. However, the optimal HBV DNA cutoff level for the initiation of antiviral treatment remains to be determined.

Efficacy of antiviral therapy during the second or the third trimester for preventing mother-to-child hepatitis B virus transmission: a systematic review and meta-analysis

For pregnant women with high viral load, antiviral therapy has been administered in addition to active and passive immune prophylaxis as a crucial adjunctive therapy to interrupt mother-to-child hepatitis B virus (HBV) transmission (MTCT). However, the time of antiviral therapy onset remains controversial. A systematic review and meta-analysis was conducted to compare the efficacy of antiviral therapy during the second or the third trimester for prevention of HBV vertical transmission. We searched nine databases for observational studies and randomized controlled trials that enrolled pregnant women with positive HBsAg treated with antivirals. The outcomes of interest were maternal HBV-DNA levels prior to delivery and the rates of HBV MTCT. We included nine studies that enrolled 1,502 pregnant women. The average HBV-DNA level before treatment was approximately 8 log₁₀ copies/mL. Compared to the onset of antiviral intervention in the third trimester, the beginning of treatment in the second trimester distinctly reduced maternal predelivery HBV-DNA levels. However, no significant difference in HBV MTCT was found between the second and third trimester groups. Furthermore, the subgroup analysis showed that there were no significant differences between groups beginning treatment at different times (second or third trimester) with regard to HBV MTCT or other evaluated endpoints. For pregnant women with HBV-DNA levels less than or equal to 8 log₁₀ copies/mL, the beginning of antiviral treatment can be delayed until the third trimester.

In utero Hepatitis B Immunization during Fetal Surgery for Spina Bifida

BACKGROUND

Fetal surgery for spina bifida aperta may lead to significantly better outcomes than postnatal repair, particularly regarding shunt-dependent hydrocephalus, independent ambulation, and voiding functions. The "Management of Myelomeningocele Study" (MOMS) represents the current benchmark, also in terms of eligibility criteria.

CASE REPORT

A positive maternal hepatitis B virus (HBV) status is a MOMS exclusion criterion. Here, we report on the first successful active and passive in utero HBV vaccination of a spina bifida fetus carried by a HBV-positive mother undergoing maternal-fetal surgery. The now 2-year-old infant is healthy, HBV negative, and drew maximal benefit from prenatal surgery.

DISCUSSION AND CONCLUSION

Taken together, this patient benefitted maximally from fetal surgery for spina bifida, despite meeting an exclusion criterion. Thus, generally speaking, eligibility criteria for fetal surgery can be challenged under certain circumstances for the benefit of the patient.

Early Start Of Tenofovir Treatment Achieves Better Viral Suppression In Pregnant Women With A High HBV Viral Load: A Real-World Prospective Study

PURPOSE

To investigate whether tenofovir disoproxil fumarate (TDF) treatment that started from the second trimester had an advantage over TDF treatment that started from the third trimester.

PATIENTS AND METHODS

Twenty 35-year-old pregnant women with hepatitis B virus (HBV) DNA >2×106 IU/mL were prospectively enrolled in this study. All participants were divided into two subgroups: the second trimester group who started TDF treatment at 24-27 weeks and the third trimester group who started TDF treatment at 28-30 weeks. The primary outcome was the change in serum HBV DNA level from baseline to delivery. Each parameter was tested every 4 weeks from TDF initiation to 3 months postpartum.

RESULTS

There were 80 pregnant women in the second trimester group and 49 pregnant women in the third trimester group. The decline in HBV DNA from baseline to delivery was more obvious in the second trimester group (4.8±1.2 log10 IU/mL) than that in the third trimester group (4.3±1.1 log10 IU/mL, p=0.041). The downward shift of haemoglobin (HB) from baseline to delivery was greater in the second trimester group (10.6±10.7 g/L) than in the third trimester group (6.3±12.3 g/L, p=0.041). The decline in HBV DNA from baseline to delivery was linearly related to the start of TDF treatment from the second trimester (β=0.50 and 95% CI: 0.26-0.75, p<0.001). There were no significant differences between the two groups regarding HBV serologic markers and safety indicators.

CONCLUSION

Starting TDF treatment from the second trimester achieved better viral suppression than starting TDF treatment from the third trimester in highly viraemic pregnant women without increasing additional adverse reactions. HB level needed frequent monitoring during treatment to avoid anaemia.

REGISTRY NUMBER

Clinical Trial No. NCT02719808.

Efficacy and safety of telbivudine and tenofovir disoproxil fumarate in preventing hepatitis B vertical transmission: A real-life practice

Mother-to-child transmission (MTCT) is a major obstacle in the elimination of hepatitis B virus (HBV) infection. Telbivudine (LdT) and tenofovir disoproxil fumarate (TDF) are the two most common antiviral medicines for preventing MTCT. However, the efficacy and safety of LdT and TDF in preventing HBV vertical transmission during the second to third trimester have not been compared rigorously. Therefore, we carried out a prospective multicentre cohort study of chronic hepatitis B in mothers with HBV DNA > 10⁶  IU/mL, receiving LdT or TDF during the second to third trimester. Among the 893 mothers enrolled, 857 (LdT/TDF/untreated group (NTx) = 396/325/136) completed consecutive follow-up with 854 infants (LdT/TDF/NTx = 395/323/136). LdT and TDF treatment resulted in a similar decrease of HBV DNA in mothers at delivery. Multivariate analysis indicated that only HBsAg titre at the baseline correlated with viral DNA decrease (P = 0.015). With intention-to-treat analysis, MTCT rates in the LdT, TDF and NTx group were 4.41%, 2.42% and 22.08%, respectively. An increasing vertical transmission rate was found to be closely associated with higher HBsAg titre, 5.32% and 17.65% infection rate was estimated in infants born to mothers with HBsAg > 4 and >5 log₁₀ IU/mL, respectively. No serious side effects were reported in either mothers or infants. LdT and TDF treatments were well tolerated and showed comparable efficacy in reducing MTCT. Higher risk of MTCT was shown in pregnant women with HBsAg > 4 log₁₀ IU/mL.

Comparing the Efficacy and Safety of Treating Chronic Hepatitis B Infection during Pregnancy with Lamivudine, Telbivudine, and Tenofovir: A Meta-analysis

Background and Aims: The perinatal transmission of hepatitis B virus (HBV) remains an important global health problem. Here, a systematic review and meta-analysis were conducted to evaluate the evidence regarding the efficacy and maternal/fetal safety of treating pregnant women with lamivudine, telbivudine (LdT), and tenofovir (TDF). Methods: A PubMed and Scopus search resulted in 1,076 records, which were reduced to 36, containing 7,717 pregnant women with chronic HBV infection and 7467 infants meeting the inclusion criteria. The latest search was in August 2019. Results: Treatment with LdT, but not lamivudine and TDF, could significantly reduce the hepatitis B virus surface antigen-positive rate (odds ratio (OR) = 0.37) in infants; it also led to higher rates of hepatitis B e antigen loss (OR = 12.14), hepatitis B e antigen seroconversion (OR = 8.93), and alanine aminotransferase normalization in mothers (OR = 1.49). Each of these treatments was able to significantly reduce HBV DNA positivity at birth (total OR = 0.19) and mother-to-child-transmission of HBV (total OR = 0.15), and to cause higher rates of HBV DNA suppression in mothers (total OR = 25.53). However, nucleos(t)ide analogues might also be involved in creatine kinase elevation (total OR = 7.48). In contrast, no significant association was found between nucleos(t)ide analogue therapy and preterm/premature births, congenital malformation, low birth weight, and abortion or fetal/infant death. The results suggested LdT's high capability of preventing mother-to-child-transmission. However, TDF failed to show significant associations to a reduced risk of mother-to-child-transmission, probably due to the low number of patients included. Conclusions: Although using either lamivudine, LdT, or TDF could lead to more favorable maternal/fetal outcomes, LdT seemed to show more potential in resolving certain infant- and maternal-related outcomes. More studies on the safety profile of such treatments are required.

Research gaps in viral hepatitis

Introduction

The World Health Organization has aimed for global elimination of both hepatitis B virus (HBV) and hepatitis C virus (HCV) by 2030. Treatments available to cure HCV and control HBV, as well as vaccination to prevent HBV infection, have certainly allowed for such bold goals, yet the final steps to usher in elimination require further evidence.

Discussion

We broadly discuss the needs for three major public health approaches. First, an effective vaccine exists for HBV and mass‐vaccination campaigns have resulted in decreases in hepatitis B surface antigen seroprevalence and overall rates of liver‐related morality. Still, HBV vaccination coverage is poor in certain regions of the world, while the reasons for such low coverage require further study. A prophylactic vaccine is probably needed to eliminate HCV, but is not being readily developed. Second, identifying HBV/HCV infected individuals remains a priority to increase awareness of disease status, particularly for key populations. Research evaluating large‐scale implementation of novel, rapid and mobile point‐of‐care tests would be helpful to determine whether increased awareness is achievable in these settings. Third, antiviral therapy allows for strong HBV suppression and HCV cure, while its access depends on financial factors among many others. Although there is strong evidence to treat key populations and specific groups with progressed disease, as stated in current guidelines, the advantages of extending treatment eligibility to decrease onward spread of HBV/HCV infection and prevent further burden of disease are lacking “real world” evidence. Novel anti‐HBV treatments are being developed to target intrahepatocellular HBV replication, but are still in the early phases of clinical development. Each of the strategies mentioned above has specific implications for HIV infection.

Conclusions

There are certainly effective tools to combat the spread of viral hepatitis and treat infected individuals – yet how they are able to reach key populations, and the infrastructure required to do so, continue to represent the largest research gap when evaluating the progress towards elimination. Continuously adapted and informed research is required to establish the priorities in achieving elimination goals.

The epidemiology of hepatitis B virus infection in Korea

The global burden of hepatitis B virus (HBV) infection is profound, and represents a public health threat as chronic infection can lead to liver cirrhosis, hepatocellular carcinoma, and death. The risk factors for chronic hepatitis B-related liver disease differ according to HBV endemicity, hepatitis B e-antigen seropositivity, and viral load. It is important to identify these risk factors and start antiviral treatment at an appropriate time according to current guidelines. The most crucial step in reducing HBV infection is prevention in infancy or early childhood, as infection at an early stage may lead to chronicity. South Korea was formerly an HBV-endemic area, but the epidemiology of HBV infection was changed by the introduction of vaccination in 1983 and nationwide immunization in 1995. The government and the private sector made efforts to reduce the prevalence of HBV infection, and Korea is on target to meet the World Health Organization goal of eliminating viral hepatitis by 2030. To eliminate hepatitis worldwide, the costs of antiviral treatment to prevent perinatal HBV transmission in pregnant women with high viremia should be covered by a national program, and strategies to reduce the prevalence of HBV infection in immigrant populations are needed.

Screening for Hepatitis B Virus Infection in Pregnant Women: US Preventive Services Task Force Reaffirmation Recommendation Statement

IMPORTANCE

Screening for hepatitis B virus (HBV) infection during pregnancy identifies women whose infants are at risk of perinatal transmission. Data from a nationally representative sample showed a prevalence of maternal HBV infection of 85.8 cases per 100 000 deliveries from 1998 to 2011 (0.09% of live-born singleton deliveries in the United States). Although there are guidelines for universal infant HBV vaccination, rates of maternal HBV infection have increased annually by 5.5% since 1998. Children infected with HBV during infancy or childhood are more likely to develop chronic infection. Chronic HBV infection increases long-term morbidity and mortality by predisposing infected persons to cirrhosis of the liver and liver cancer.

OBJECTIVE

To update the 2009 US Preventive Services Task Force (USPSTF) recommendation on screening for HBV infection in pregnant women.

EVIDENCE REVIEW

The USPSTF commissioned a reaffirmation evidence update to identify substantial new evidence sufficient enough to change the prior recommendation. The USPSTF targeted its evidence review on the effectiveness and potential harms of screening and the effectiveness and harms of case management to prevent perinatal transmission.

FINDINGS

The USPSTF previously found adequate evidence that serologic testing for hepatitis B surface antigen accurately identifies HBV infection. Interventions are effective for preventing perinatal transmission, based on foundational evidence and observational studies of US case management programs. In addition, there is evidence that over time, perinatal transmission has decreased among women and infants enrolled in case management, providing an overall substantial health benefit. Therefore, the USPSTF reaffirms its previous conclusion that there is convincing evidence that screening for HBV infection in pregnant women provides substantial benefit.

CONCLUSIONS AND RECOMMENDATION

The USPSTF recommends screening for HBV infection in pregnant women at their first prenatal visit. (A recommendation).

Modelling cost-effectiveness of tenofovir for prevention of mother to child transmission of hepatitis B virus (HBV) infection in South Africa

BACKGROUND

International sustainable development goals for the elimination of viral hepatitis as a public health problem by 2030 highlight the need to optimize strategies for prevention, diagnosis and treatment of hepatitis B virus (HBV) infection. An important priority for Africa is to have affordable, accessible and sustainable prevention of mother to child transmission (PMTCT) programmes, delivering screening and treatment for antenatal women and implementing timely administration of HBV vaccine for their babies.

METHODS

We developed a decision-analytic model simulating 10,000 singleton pregnancies to assess the cost-effectiveness of three possible strategies for deployment of tenofovir in pregnancy, in combination with routine infant vaccination: S1: no screening nor antiviral therapy; S2: screening and antiviral prophylaxis for all women who test HBsAg-positive; S3: screening for HBsAg, followed by HBeAg testing and antiviral prophylaxis for women who are HBsAg-positive and HBeAg-positive. Our outcome was cost per infant HBV infection avoided and the analysis followed a healthcare perspective.

RESULTS

Based on 10,000 pregnancies, S1 predicts 45 infants would be HBV-infected at six months of age, compared to 21 and 28 infants in S2 and S3, respectively. Relative to S1, S2 had an incremental cost of $3940 per infection avoided. S3 led to more infections and higher costs.

CONCLUSION

Given the long-term health burden for individuals and economic burden for society associated with chronic HBV infection, screening pregnant women and providing tenofovir for all who test HBsAg+ may be a cost-effective strategy for South Africa and other low/middle income settings.

Prevention of perinatal hepatitis B virus transmission

PURPOSE

Chronic hepatitis B virus (HBV) infection remains endemic and continues to cause significant morbidity and mortality. It is a global health issue and the World Health Organization aims to eradicate HBV by 2030. Since vertical transmission accounts for the majority of chronic HBV infection, pregnancy offers an excellent opportunity to achieve complete HBV eradication by providing effective immunization of the offspring.

METHODS

We reviewed recent publications identified from PubMed database using a combination of the relevant keywords for HBV, pregnancy, vertical transmission, immunoprophylaxis failure and antiviral treatment.

RESULTS

We summarized the evidence of factors associated with, and measures to reduce and prevent maternal to child transmission, including the use of antiviral treatment during pregnancy to prevent immunoprophylaxis failure. Evidence suggested that highly viremia mother can be offered antenatal antiviral treatment to prevent immunoprophylaxis failure. We elaborated the viral load threshold to start maternal antiviral treatment and the importance of timely neonatal vaccination. A clinical algorithm to manage HBV carriers during pregnancy was proposed.

CONCLUSION

Eradication of HBV is achievable with optimal management of HBV carriers, especially during pregnancy by interruption of vertical transmission. Routine antenatal screening and neonatal immunoprophylaxis remain the key measures to reduce the global HBV burden, and additional antenatal antiviral treatment could further minimize the chance of persistent infection in newborns.