Safety and efficacy of telbivudine in late pregnancy to prevent mother-to-child transmission of hepatitis B virus: A multicenter prospective cohort study

Elective cesarean section and bottle-feeding do not reduce infection of hepatitis B in infants of high viremic mothers: a retrospective study

BACKGROUND

Studies on the issue of whether elective cesarean section (ECS) may reduce mother-to-child transmission (MTCT) of HBV in infants of carrier mothers with high viremia (HBV DNA > 2 × 105 IU/ml) showed inconsistent results. In addition, whether breastfeeding may cause MTCT of HBV is still a concern. We compared the MTCT rates in infants born to non-antiviral mothers with HBV DNA > 2 × 105 IU/ml with different delivery and feeding modes.

METHODS

In total, 460 mothers with HBV DNA > 2 × 105 IU/ml and their 462 infants (2 twin sets) were included. Hepatitis B surface antigen (HBsAg) and antibodies against HBsAg (anti-HBs) in infants were quantitatively tested at 7-14 month age. Chi-square or Fisher's exact tests was applied to analysis the MTCT rates with different delivery and feeding modes.

RESULTS

Of the 462 infants, 214 (46.3%) were delivered by ECS and 178 (38.5%) were exclusively bottle-fed. Overall, 11 (2.4%) of 462 infants were HBsAg positive at 9.9 ± 2.4 month age. The MTCT rate (2.0%, 5/248) in vaginally delivered infants was similar to that (2.8%, 6/214) in infants delivered with ECS (χ2 = 0.307, p = 0.580), and the rate (3.2%, 9/284) in breastfed infants was also similar to that (1.1%, 2/178) in exclusively bottle-fed infants (χ2 = 2.190, p = 0.139). Moreover, the MTCT rates in infants with vaginal delivery and breastfed, ECS and breastfed, vaginal delivery and bottle-fed, and ECS and bottle-fed had no statistical significance, with 2.5%, 3.9%, 1.1%, and 1.1%, respectively (χ2 = 2.090, p = 0.538).

CONCLUSIONS

With timely immunoprophylaxis, ECS and bottle-feeding cannot reduce MTCT of HBV in infants born to high viremic mothers without antiviral therapy. ECS or bottle-feeding should not be recommended for the prevention of perinatal HBV infection.

Screening for viral hepatitis carriage

Viral hepatitis during pregnancy is common globally. In this review, we focus on the antenatal screen for hepatitis A, B, C and E, the prevention of mother-to-child transmission (MTCT) of hepatitis B and C, and the management of hepatitis A, B, C and E during pregnancy. Neonatal timely administration of hepatitis B immunoglobulin and hepatitis B vaccine is the cornerstone for preventing MTCT of hepatitis B virus (HBV), and perinatal antiviral prophylaxis with tenofovir disoproxil fumarate in mothers with positive HBeAg or HBV DNA >2 × 105 IU/ml also plays important roles in further reducing MTCT. Avoidance of risk practices in managing labor and delivery process of women with HCV infection may be useful to reduce MTCT of HCV. Early recognition of severe hepatic injury or liver failure associated with hepatitis viruses by regular liver function tests is critical to prevent maternal mortality associated with hepatitis.

Effectiveness and Safety of Tenofovir Alafenamide Fumarate in the Prevention of Perinatal Hepatitis B Transmission: A Meta-Analysis

AIM

This study aimed to assess the effectiveness and safety of tenofovir alafenamide fumarate (TAF) in the prevention of mother-to-child transmission (MTCT) of hepatitis B virus (HBV).

METHODS

We performed a meta-analysis of studies from the Cochrane Library, PubMed, ClinicalTrials.gov, Web of Science, EMBASE, China National Knowledge Infrastructure (CNKI), China Medical Information Network, and Wanfang databases. The databases were searched from inception to January 7, 2023, for cohort studies and randomized controlled trials (RCTs) comparing the use of TAF antivirals to other antivirals during pregnancy. We combined the data by means of a random-effect DerSimonian-Laird model and risk ratios (RRs) or a random-effect inverse variance model and standardized mean differences (SMDs) to determine the influence on mothers and infants. Our primary outcomes were infant weight, height, head size, birth defects, and Apgar scores. Additionally, we assessed whether newborns tested positive for hepatitis B surface antigen (HBsAg) at birth and at six months of age. The secondary outcomes of our investigation were alterations in levels of HBV deoxyribonucleic acid (DNA), alanine aminotransferase (ALT), total bilirubin (TBIL), blood creatinine, and urine β2-microglobulin (β2-M) in mothers.

RESULTS

An extensive literature search identified 216 relevant publications; three cohort studies and two RCTs were included in this study. A total of 341 mothers were treated with TAF, and 342 were treated with other antiviral agents. TAF was as effective as other antiviral medications at lowering HBV MTCT rates at birth and at 6 months of age and ALT, TBIL, and HBV DNA levels. Moreover, compared with other antiviral drugs, TAF did not affect infant weight, height, head size, Apgar scores, and birth defects or maternal blood creatinine or β2-M levels.

CONCLUSIONS

TAF antiviral therapy during pregnancy was found to be safe for both mothers and fetuses.

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.

Impact of timing on protection of combined immunoprophylaxis in preventing mother-to-child transmission of hepatitis B virus: a retrospective study

Objective: To evaluate the impact of timing combined immunoprophylaxis on mother-to-child transmission (MTCT) of the hepatitis B virus (HBV) in pregnant women living with hepatitis B. Methods: A retrospective cohort study was included HBsAg-positive pregnant women who delivered full-term at Tianjin Third Central Hospital from January 2019 to December 2021. The objective of this study is to determine whether early administration of hepatitis B immune globulin (HBIG) and the first dose of hepatitis B vaccination after birth can further improve protection. Result: A total of 694 pregnant women living with hepatitis B were included; 93 infants from these mothers were lost to follow-up [including moving (n = 21), emigrating (n = 26), changing contact information (n = 27), and other reasons (n = 19)], leaving 601 infants for analysis. The incidence in babies born to mothers with hepatitis B was 1.50% (9/601). Based on the different timing of combined immunoprophylaxis administration after birth, 601 infants were divided into two groups (within 2 h and within 2-12 h). The incidence in babies born to mothers with hepatitis B were 0.32% (1/308) and 2.73% (8/293) for infants who received combined immunoprophylaxis within 2 h and between 2 and 12 h of birth, respectively (p = 0.037). The infection incidence of infants born to HBeAg-positive mothers and HBeAg-positive mothers who did not receive antiviral treatment during pregnancy was lower in the 2-h group compared to the 2-12 h group (0.72% vs. 5.84%, p = 0.04 and 1.20% vs. 9.46%, p = 0.047). Conclusion: Using combined immunoprophylaxis as soon as possible (within two hours of birth) may protect against MTCT of HBV more.

Can newborn infants with positive HIV soon after birth be diagnosed with intrauterine infection?

BACKGROUND

Mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) can occur intrauterine, intrapartum, and postpartum. Currently, infants with confirmed positive results in virological tests before 48 h of age are defined as having intrauterine infection.

AIM

We herein review the literature that identifies emerging challenges in diagnosing intrauterine HIV infection to rethink the current diagnostic criteria.

FINDINGS

A number of reports have shown that some infants who were diagnosed with intrauterine HIV infection after birth became negative for HIV in the subsequent follow-ups, including negative HIV antibodies at the age of 12-18 months. Such "clearance" of HIV was attributed to various reasons: neonatal antiretroviral treatment (ART), false positivity, strong host immune response, or unknown factors in maternal breast milk.

DISCUSSIONS

Positive HIV tests in newborn infants shortly after birth do not necessarily indicate HIV infection, because maternal HIV can enter fetal circulation intrapartum due to the repetitive, strong uterine contractions. The infants are therefore exposed to, but may not yet be infected with HIV at that time. The current diagnostic criteria cannot differentiate HIV exposure from HIV infection, leading to so-called "challenges in diagnosing intrauterine HIV infection". Those infants diagnosed with intrauterine infection who cleared HIV later were less likely to have been truly infected with HIV, but more likely to have been exposed to HIV. Moreover, we suggest that the determination of HIV antibody titers in infants' serial serum samples can provide valuable information to distinguish intrapartum exposure from intrauterine infection.

Efficacy and safety of long-term postpartum antiviral therapy in hepatitis B virus-infected mothers receiving prophylactic tenofovir disoproxil fumarate treatment

OBJECTIVES

This study aimed to evaluate the efficacy and safety of long-term postpartum tenofovir disoproxil fumarate (TDF) therapy in hepatitis B virus (HBV)-infected mothers with high viral load.

METHODS

In this retrospective cohort study, HBV-infected mothers with HBV DNA>2 × 10 5  IU/mL who initiated TDF prophylaxis treatment during pregnancy were divided into TDF continuation and discontinuation groups according to whether they stopped TDF treatment within 3 months after birth or not. Virological and biochemical markers were collected before TDF treatment, antepartum and postpartum.

RESULTS

In 131 women followed for a median of 18 months postpartum, alanine aminotransferase (ALT) abnormality rate was significantly lower in TDF continuation group vs. discontinuation group (39.4% vs. 56.9%, P  = 0.045), and continuous TDF therapy in postpartum was independently associated with lower risk of ALT flares [OR = 0.308, 95% confidence interval (CI), 0.128-0.742; P  = 0.009]. Long-term postpartum TDF treatment can promote the decline of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) levels, but the HBeAg seroconversion rate in two groups was not significant (15.5% vs. 11.7%, P  = 0.541). There were no statistical differences in bone metabolism markers between two groups ( P  > 0.05). Compared with the TDF discontinuation group, TDF continuation group had a significantly lower estimated glomerular filtration rate level and higher creatinine level in postpartum but within normal ranges ( P  < 0.05).

CONCLUSIONS

For pregnant women who received prophylactic TDF treatment, long-term TDF therapy continued in postpartum can reduce the risk of ALT flares and promote the rapid decline of HBeAg and HBsAg levels.

Minimal adverse outcomes of postnatal cytomegalovirus infection in term or moderate and late preterm infants

OBJECTIVE

The aim of study was to investigate at what extent breastfeeding and vaginal delivery can increase mother-to-child transmission of cytomegalovirus (CMV) and to observe the clinical outcomes of postnatal infection in term or moderate and late preterm infants.

METHODS

In this retrospective study of prospectively collected clinical data and serum samples, during 2012-2015, 380 women with CMV IgG positive/IgM negative and their 384 infants (4 twin pairs) with gestational age ≥32 weeks were included. CMV IgG and IgM were measured with enzyme-linked immunosorbent assay.

RESULTS

Of 384 infants followed up at 10.2 ± 2.3 months age, 177 (46.1%) were defined with CMV infection based on the presence of higher CMV IgG levels than in their mothers. The infection rate in 190 breastfed infants was higher than in 194 formula-fed infants (62.6% vs. 29.9%, P < 0.001). Vaginally delivered infants (172) had higher CMV infection rate than 212 infants delivered by caesarean section (55.2% vs. 38.7%, P = 0.001). Compared with formula feeding and caesarean section, breastfeeding and vaginal delivery increased postnatal CMV infection respectively (OR = 3.801, 95% CI 2.474-5.840, P < 0.001; OR = 1.818, 95% CI 1.182-2.796, P = 0.007). Nevertheless, compared to uninfected infants, CMV-infected infants had comparable height and body weight and showed no adverse effect on the liver enzymes.

CONCLUSION

Breastfeeding and vaginal delivery can increase postnatal CMV infection; however, the infection does not influence the growth of the term infants or preterm infants with gestational age ≥32 weeks. Thus, breastfeeding should be encouraged in these infants regardless of maternal CMV IgG status.

Analysis of the positive results and influencing factors of hepatitis B antibody in hospitalized neonates with AgHBs positive mothers

Purpose

To investigate the results of positive antibody to hepatitis surface antigen(anti-HBs)in hospitalized neonates whose mothers were hepatitis B surface antigen (AgHBs) positive and to explore the influencing factors.

Method

The study subjects were hospitalized neonates whose mothers were positive for AgHBs. According to the serological test results of five immune markers of hepatitis B virus (HBV), they were divided into positive for anti-HBs and negative for anti-HBs. Retrospective analysis of relevant factors affecting results of anti-HBs.

Result

269 cases (80.78%) were positive for anti-HBs and 64 cases (19.22%) were negative for anti-HBs. Univariate analysis results: the number of hepatitis B immunoglobulin (HBIG) injections after birth, whether HBIG was injected within 6 h, whether Hepatitis B vaccine (Hep B) was injected within 6 h, whether combined immunization within 12 h, whether Hep B was vaccinated on time after discharge, whether preterm birth, and whether low birth weight infants were statistically significant (P < 0.05). The results of binary logistic regression analysis: HBIG injection time ≤6 h (OR = 0.213), combined immunization time ≤12 h (OR = 0.024) were protective factors; premature infants (OR = 7.175), ALB/GLO (OR = 9.792) and failure to complete three vaccinations on time (OR = 12.659) were risk factors (P < 0.05).

Conclusion

Although China has implemented a national immunization program, vaccination of hospitalized neonates whose mothers are positive for AgHBs has not been effective. Therefore, it is recommended to strengthen training for medical staff and families to ensure that neonates can complete the three doses of vaccination on time after discharge from the hospital and to strengthen follow-up for premature infants.

Tenofovir Alafenamide for Pregnant Chinese Women With Active Chronic Hepatitis B: A Multicenter Prospective Study

BACKGROUND & AIMS

Data on long-term tenofovir alafenamide (TAF) therapy for pregnant women with active chronic hepatitis B (CHB) (immune clearance and reactivation phases, currently and previously diagnosed) and their infants are lacking.

METHODS

Pregnant women with active CHB treated with TAF and tenofovir disoproxil fumarate (TDF) were enrolled in this multicenter prospective study, and infants received immunoprophylaxis. The primary outcomes were rates of adverse (safety) events in pregnant women and defects in infants and fetuses. The secondary outcomes were virologic responses in pregnant women, infants' safety, hepatitis B surface antigen (HBsAg) status, and growth conditions.

RESULTS

One hundred three and 104 pregnant women were enrolled and 102 and 104 infants were born in the TAF and TDF groups, respectively. In the TAF group, the mean age, gestational age, alanine aminotransferase level, and viral loads at treatment initiation were 29.3 years, 1.3 weeks, 122.2 U/L, and 5.1 log10 IU/mL, respectively. TAF was well-tolerated, and the most common adverse event was nausea (29.1%) during a mean of 2 years of treatment. Notably, 1 (1.0%) TAF-treated pregnant woman underwent induced abortion due to noncausal fetal cleft lip and palate. No infants in either group had birth defects. In the TAF group, the hepatitis B e antigen seroconversion rate was 20.7% at postpartum month 6, infants had normal growth parameters, and no infants were positive for HBsAg at 7 months. The TDF group had comparable safety and effectiveness profiles.

CONCLUSIONS

TAF administered throughout or beginning in early pregnancy is generally safe and effective for pregnant women with active CHB and their infants.

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.

Hepatitis B Viral Markers in the Human Milk of HBsAg-Positive Mothers: An Observational Study

BACKGROUND

Quantification of viral antigens and viral loads in human milk samples from mothers infected with hepatitis B virus is largely unknown.

RESEARCH AIM

The aim of the study was to quantitatively measure the levels of viral antigens and deoxyribonucleic acid of hepatitis B virus in human milk from mothers infected with hepatitis B virus.

METHODS

Fifty-five pairs of milk and serum samples from mothers with positive hepatitis B surface antigen, including 11 hepatitis B e antigen positive, were quantitatively tested to measure viral antigens by microparticle enzyme immunoassay and viral loads by real-time polymerase chain reaction assay.

RESULTS

The median level of hepatitis B surface antigen in the human milk samples of mothers with positive or negative hepatitis B e antigen was each lower than that in the sera, respectively (1.10 vs. 4.32 log₁₀ IU/ml, t = 10.693, p < .001; -0.77 vs. 2.53 log₁₀ IU/ml, t = -25.135, p < .001). The titers of hepatitis B surface antigen or hepatitis B e antigen in the human milk samples were each correlated with that in maternal serum. The detectable level of deoxyribonucleic acid of hepatitis B virus in human milk ranged from 1.42-5.27 log₁₀ IU/ml, whereas that in maternal sera was 1.44-8.66 log₁₀ IU/ml. The viral level in human milk was not correlated with that in maternal circulation.

CONCLUSION

The present study data illustrate the relatively low titers of viral markers in the milk of mothers with positive hepatitis B surface antigen.

The optimal interval for post-vaccination serological test in infants born to mothers with positive hepatitis B surface antigen

Postvaccination serologic testing (PVST) is utilized to monitor the success or failure of vaccination against hepatitis B virus (HBV) infection in infants of hepatitis B surface antigen (HBsAg) positive mothers. This secondary analysis of 1255 infants of HBsAg-positive mothers at 7-14 months age included in two prospective studies aimed to determine the optimal interval for PVST after three hepatitis B vaccine doses. HBsAg and anti-HBs were quantitatively tested with microparticle enzyme immunoassay. The average PVST interval was 3.8 ± 2.2 months. Overall, 1.7% (21/1255) infants had anti-HBs <10 mIU/mL. The non-response rates were 1.6%, 1.1%, 0.9%, 0.7%, 1.1%, 0.7%, and 5.7% when PVST was performed at an interval of 1, 2, 3, 4, 5, 6, and 7-8 months after the third vaccine dose, respectively. Compared with 1 month of PVST interval, the non-response rate in infants who underwent PVST 7-8 months was significantly higher (χ² = 4.616, P = .032). Anti-HBs titers were significantly declined in infants with medium responses when PVST was performed with longer intervals (χ² = 27.592, P < .001), actually declined from interval of 6, and 7-8 months (Z = -3.177, P = .001 and Z = -3.715, P < .001), respectively. These results indicate that PVST may be performed at the age of 7-12 months for infants vaccinated on 0, 1, and 6-month schedule. To identify non-responders as early as possible, we suggest that PVST is performed at 7 months age or 1 month after the final vaccine dose.

Elimination of hepatitis B virus infection in children: experience and challenge in China

ABSTRACT

Chronic hepatitis B virus (HBV) infection is a serious health issue because of its severe sequelae. Prevention of mother-to-child transmission (MTCT) of HBV is critical to eliminate chronic HBV infection. Here, we reviewed the progress toward the elimination of HBV infection in children in China in the recent decade. A universal hepatitis B vaccination program started from 2002 has been intensified, with the coverage of timely birth dose >95% of all newborn infants from 2012. Since 2011, China has taken a nationwide program to administer hepatitis B immunoglobulin (HBIG) with free of charge in all neonates of HBV-infected mothers, leading to a significant increment of timely use of HBIG. The prevalence of hepatitis B surface antigen (HBsAg) was declined from around 10% among children in 1980s to <0.5% among children born after 2011. Administration of oral antiviral agents in HBV-infected pregnant women with HBV DNA >2 × 105 U/mL during the third trimester is increasing, which will further reduce MTCT of HBV. However, there are some challenges in the elimination of HBV infection in children, which need to overcome by the concerted efforts. Nevertheless, it is anticipated that China will achieve the goal set by the World Health Organization that the prevalence of HBsAg in children aged <5 years is ≤0.1% by 2030.

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.

Reduced mother-to-child transmission of hepatitis B after implementation of completely charge-free active-passive immunoprophylaxis: an observational cohort study

Objectives: China has implemented universal hepatitis B vaccination since 2002 and provided charge-free hepatitis B immunoglobulin (HBIG) to infants of HBV-infected mothers since July 2011. We aimed to compare mother-to-child transmission (MTCT) in children born before and since July 2011.Methods: In total, 5,149 children of HBV-infected mothers were tested for HBV markers. Group one contained 1,160 children born during August 2002-June 2011 and group two contained 3,989 children born during July 2011-June 2016.Results: In total, 92 (1.8%, 95% confidence interval [95%CI] 1.4-2.2) children were infected with HBV. None (0%, 95%CI 0.0-0.1) of 3,716 children of mothers with negative hepatitis B e antigen (HBeAg) was infected, whereas 92 (6.4%, 95%CI 5.2-7.8) of 1,433 children of HBeAg-positive mothers were infected (p < 0.0001). Among children of HBeAg-positive mothers, MTCT occurred in 10.3% (19/185) (95%CI 6.3-15.6) in group one and 5.8% (73/1,248) (95%CI 4.6-7.3) in group two (p = 0.02).Conclusions: Implementing charge-free active-passive immunoprophylaxis greatly reduces MTCT of HBV in children of HBeAg-positive mothers, highlighting the importance of timely administration of both hepatitis B vaccine and HBIG to prevent MTCT. The still remaining MTCT suggests that reducing maternal virus load before delivery is an additional important measure.

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.

The safety and efficacy of tenofovir disoproxil fumarate used throughout pregnancy for mothers with chronic hepatitis B

BACKGROUND

Antiviral therapy throughout pregnancy in women with chronic hepatitis B (CHB) during pregnancy has been suggested; however, the data of tenofovir disoproxil fumarate (TDF) are limited. The aim of this study was to evaluate the safety and efficiency in women with CHB.

METHODS

It was a single-center, retrospectively study. Eighty-one women received TDF 300 mg/day before pregnancy. Sixty-three women did not receive antiviral treatment. All infants in both groups received immunoprophylaxis. Mothers and infants were followed at least postpartum 7 months. The primary endpoint was the safety of mothers and infants. The secondary endpoints were mother-to-child transmission (MTCT) rate and hepatitis B virus (HBV) DNA suppression.

RESULTS

TDF was well tolerated in the mothers. The rates of neonatal congenital abnormalities were similar between the two groups (3.7% or 3/81 versus 3.3% or 2/63, P = 1.000). There were also no significant differences in infant length and weight, Apgar score (1 minute), rate of low birth weight, gestational age, or rate of cesarean section between the two groups. TDF significantly reduced the viral load (3.4 ± 0.5 log IU/mL versus 6.3 ± 1.5 log IU/mL, P < 0.001) and the ALT levels (19.9 ± 10.2 versus 46.8 ± 44.8 U/L, P < 0.001) before delivery. At 7-month postpartum, the MTCT rate was 0% in the TDF-treated group when compared with 6.3% (4/63) in the untreated group (P = 0.035).

CONCLUSION

TDF used throughout pregnancy can safely reduce the rate of MTCT.

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.

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.

Efficacy and safety of continuous antiviral therapy from preconception to prevent perinatal transmission of hepatitis B virus

Few studies were conducted to assess safety and efficacy of continuous antiviral therapy administrated from preconception. In the present study, 136 eligible women with chronic HBV infection were recruited, and assigned to active chronic hepatitis B (CHB) (Group A, B or C) or chronic HBV carrier (Group D). Antiviral therapy was administrated in preconception (Group A), in early (Group B) or late pregnancy (Group C and Group D). Immunoprophylaxis was administrated to all infants. Mothers’ HBV status and ALT were assessed at delivery and 7 months postpartum. Offspring’s HBV status was examined at 7 months old. Group A women showed low HBV DNA level and normal ALT throughout pregnancy. All women at delivery had an HBV DNA level of less than 10⁶ IU/ml, but the proportion of patients with lower HBV DNA level in Group A was higher than any of other three groups (P < 0.05). No differences in obstetrical complications were found among the four groups. None of infants who completed follow-up showed positive HBsAg at age of 7 months. Congenital malformation and infant growth indicators were similar among study cohorts. Continuous antiviral therapy from preconception to entire pregnancy is effective and safe for active CHB mothers and their infants.

Increased protection of earlier use of immunoprophylaxis in preventing perinatal transmission of hepatitis B virus

BACKGROUND

Passive-active immunoprophylaxis against mother-to-child transmission (MTCT) of hepatitis B virus (HBV) recommends administer hepatitis B immunoglobulin (HBIG) and birth dose hepatitis B vaccine in infants within 12 or 24 hours after birth. With this protocol, MTCT of HBV still occurs in 5-10% infants of HBV-infected mothers with positive hepatitis B e antigen (HBeAg).

METHODS

The present study aimed to investigate whether earlier administration of HBIG and hepatitis B vaccine after birth can further increase the protection efficacy.

RESULTS

Totally, 1140 HBV-infected pregnant women were enrolled, and 982 infants (9 twins) of 973 mothers were finally followed up at 9.6 ± 1.9 months age. HBIG and birth dose vaccine were administered in newborn infants with a median 0.17 hour (0.02-1.0) after birth. The overall rate of MTCT was 0.9% (9/982), with none (0%) of 607 infants of HBeAg-negative mothers and 9 (2.4%) of 375 infants of HBeAg-positive mothers. All nine HBV-infected infants were born to mothers with HBV DNA >2.75×106 IU/ml. Maternal HBV DNA levels >1×106 IU/ml was an independent risk factor (OR = 10.627, 95% CI: 2.135-+∞) for immunoprophylaxis failure.

CONSLUSIONS

Earlier use (within one hour after birth) of HBIG and hepatitis B vaccine can provide better protection efficacy against MTCT of HBV.

Hepatitis B vaccine development and implementation

Vaccination against hepatitis B is the most effective strategy to control HBV infection. The first licensed hepatitis B vaccine was developed by the purification of hepatitis B surface antigen (HBsAg) from plasma of asymptomatic HBsAg carriers. Then, the recombinant DNA technology enabled the development of recombinant hepatitis B vaccine. A series of three doses vaccine can elicit long-term protection more than 30 y. Concurrent use of hepatitis B immunoglobulin and hepatitis B vaccine has substantially reduced the mother-to-child transmission of HBV, nearly zero infection in children of carrier mother with negative hepatitis B e antigen (HBeAg) and 5-10% infection in children of HBeAg-positive mothers. By the end of 2018, 189 countries adopted universal hepatitis B vaccination program, which has dramatically reduced the global prevalence of HBsAg in children <5 y of age, from 4.7% in the prevaccine era to 1.3% in 2015. However, the implementation of universal hepatitis B vaccination in some regions is suboptimal and timely birth dose vaccine is not routinely administered in more than half of newborn infants. Optimal worldwide universal hepatitis B vaccination requires more efforts to overcome the social and economic challenges.

Efficacy and safety of telbivudine treatment for the prevention of HBV perinatal transmission

To observe the efficacy of telbivudine in chronic hepatitis B (CHB) women with high viral load during pregnancy and the long-term effects on intelligence, growth, and development of the newborns.A total of 87 patients were included. Forty-two patients received telbivudine orally 600 mg per day and treatment initiated from 12 weeks after gestation until the 12th postpartum week. Forty-five patients were untreated according to principle of informed consent. All infants received injection of hepatitis B immune globulin (HBIG; 200 IU) and were vaccinated with recombinant HBV vaccine. Wechsler preschool intelligence scale was used to assess mental and neuropsychological developments of these children till they were 6 years old. Data including serum HBV DNA viral load, Apgar score, and scores of Wechsler preschool intelligence scale were analyzed and compared.Levels of both serum HBV DNA and ALT in patients who received telbivudine were significantly decreased at the 12th week after delivery, compared with baseline levels (P < .01). No significant changes were observed in patients not receiving telbivudine (P > .05). Serum HBV DNA and ALT levels at the 12th week after delivery in the telbivudine group were significantly lower than those of patients without telbivudine (P < .01). The serum HBsAg-positive rate in neonates 7 months of age was 0%, which was significantly lower than that in control group (11.11%) (P < .05). No statistical differences were observed between the 2 groups regarding maternal cesarean section rate, adverse pregnancy rate, postpartum bleeding rate, neonatal body mass, Apgar score, neonatal malformation incidence, or intelligence development of newborn.Telbivudine is effective to reduce the viral load in CHB mothers with high viral load and could lower the perinatal transmission rate. Both mental and physical development in neonates with exposure to telbivudine during perinatal period were similar to those without telbivudine exposure.

Quasispecies characteristic in "a" determinant region is a potential predictor for the risk of immunoprophylaxis failure of mother-to-child-transmission of sub-genotype C2 hepatitis B virus: a prospective nested case-control study

OBJECTIVE

This study was performed to explore the correlation between the characteristics of hepatitis B virus (HBV) quasispecies in HBV-infected pregnant women and the risk of immunoprophylaxis failure for their infants.

DESIGN

In this prospective nested case-control study, the characteristics of HBV quasispecies in mothers whose infants were immunoprophylaxis success (control group) and those whose infants were immunoprophylaxis failure (case group) were analysed by the clone-based sequencing of full-length HBV genome and next-generation sequencing (NGS) of "a" determinant region, and were compared between the two groups.

RESULTS

The quasispecies characteristics including mutant frequency, Shannon entropy and mean genetic distance at amino acid level of "a" determinant region were significantly lower in case group than that in control group, using the full-length HBV genome clone-based sequencing assay. These results were confirmed by NGS assay. Notably, we discovered that the differences were also significant at nucleotide level by NGS assay. Furthermore, the risk of immunoprophylaxis failure could be predicted by analysing the three HBV quasispecies characteristics either at nucleotide level or at amino acid level of "a" determinant region, and the corresponding predictive values were tentatively set up.

CONCLUSIONS

HBV quasispecies with a more complex mutant spectrum in "a" determinant region might be more vulnerable to extinct through mother-to-child-transmission (MTCT). More importantly, analysing HBV quasispecies characteristics in pregnant women with high HBV DNA load might be helpful to predict the high-risk population of immunoprophylaxis failure, and consequently provide accurate intervention against MTCT of HBV.

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 and safety of antiviral therapy for HBV in different trimesters of pregnancy: systematic review and network meta-analysis

BACKGROUND

Several antiviral agents licenced for blocking mother-to-child transmission (MTCT) of HBV, but their relative efficacy beginning from different trimesters has scarce been evaluated. We aimed to conduct a network meta-analysis to statistically differ the efficacy and safety of each antiviral agents initiating on different timings in preventing mother-to-infant transmission of HBV.

METHODS

Studies were included from PubMed, EMBASE, Web of Science, and Cochrane databases through July 1, 2019. Eligible studies recruited randomized controlled trials and nonrandomized studies reporting about infant or/and maternal efficacy and safety outcomes and were screened by two investigators independently. Extracted data were analyzed by pair-wised and network meta-analysis, respectively.

RESULTS

3 Randomized and 32 nonrandomized studies enrolling 6738 pregnant female were included. Using network analysis, any antiviral agent interrupted HBV vertical transmission much more effectively than placebo. No agent showed significant efficacy different from others, but a strong trend toward significance was found in telbivudine and tenofovir, of which had the highest probability of being ranked the first- or second-best treatment for reducing MTCT of HBV. The treatment applied in the first and second trimester had a similar efficacy in preventing MTCT. Compared with the initiation during the third trimester, lower rate of MTCT was revealed when antiviral therapy was administrated before third trimester, (RR = 0.045, 95% CI 0.0053 to 0.20); a similar effect at delivery on suppressing maternal HBV DNA level and converting serum HBeAg were achieved if the timing of antiviral treatment started prior, but an obvious improvement of normalizing ALT flare was calculated out; no statistically differences among maternal and fetal safety outcomes were found if mothers received antiviral agents before pregnant 28 weeks.

CONCLUSION

This network meta-analysis recommended the earlier use of telbivudine or tenofovir, tends to be better to prevent MTCT of HBV in pregnancy with no increased adverse maternal or fetal outcomes.

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.

Genotypic Resistance Remains A Concern In Chronic Hepatitis B Patients With High Viral Load After Lamivudine And Adefovir Combination Therapy

Aims

Previous studies have shown that baseline high viral load is closely related to treatment response in chronic hepatitis B (CHB). This study was designed to evaluate the differences of treatment responses between de novo lamivudine (LAM) plus adefovir (ADV) combination therapy compared with entecavir monotherapy (ETV).

Methods

A total of 185 HBeAg-positive CHB patients with high viral load were enrolled and assigned to the LAM+ADV group (n=90) or ETV group (n=95). Clinical variables are extracted from medical records.

Results

No significant differences in baseline variables were found between the two groups before antiviral treatment. After 104 weeks of antiviral therapy, the mean HBV DNA viral load in the LAM+ADV group decreased from 8.01±0.65 log₁₀ copies/mL to 0.41±1.04 log₁₀ copies/mL, compared with 8.04±0.57 log₁₀ copies/mL to 0.57±1.28 log₁₀ copies/mL in the ETV group (P=0.35). The virological response rate of LAM+ADV group was 82.2% (74/90) at 104 weeks of treatment, and 80.0% (76/95) in the ETV group (P=0.70). For HBeAg serological responses, HBeAg loss occurred in 23.3% (21/90) and 17.9% (17/95) in the LAM+ADV group and the ETV group, respectively (P=0.36). HBeAg seroconversion was observed in 15.6% (14/90) and 15.8% (15/95) in the LAM+ADV group and ETV group, respectively (P=0.96). However, after 104 weeks of treatment, genotypic resistance was confirmed in 8 cases in the LAM+ADV group, a proportion of 8.8% (8/90), compared with an absence of genotypic resistance in the ETV group (P=0.003).

Conclusion

Both de novo combination therapy of LAM+ADV and ETV monotherapy could effectively inhibit HBV replication in patients with high viral load. However, the rate of genotypic resistance in LAM+ADV treatment remains a concern. For CHB patients with high viral load, ETV treatment may be superior.

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.

Efficacy and safety of telbivudine to prevent mother-to-child transmission of hepatitis B virus in middle- and late-stage pregnancy with high viral loads

OBJECTIVE

To observe the efficacy and safety of telbivudine on mother-infant blockade in pregnant women with hepatitis B virus (HBV) DNA.

METHODS

A total of 141 pregnant women between 24 and 28 weeks of gestation and chronic HBV carriers with HBV DNA ≥10⁶  copies/mL were enrolled, 105 in the treatment group and 36 in the control group. The treatment group was given telbivudine 600 mg/d oral, and the control group did not use antiviral drugs. Hepatitis B immunoglobulin 200 IU intramuscular injection and hepatitis B vaccine (HBVac) 10 μg subcutaneous injection were given to the infants in both groups within 12 hours after birth, and 10 μg of HBVac was subcutaneously injected when the infants were 1-month and 6-month old. Safety endpoints including HBV DNA quantification, liver function, CK were observed before treatment, 4 weeks after treatment, before delivery, and 24 weeks after delivery.

RESULTS

There was no difference in HBV DNA levels between the two groups before treatment and 6 months after delivery (P > .05). The HBV DNA level in the treatment group was significantly lower than that in the control group before delivery (P < .05). Between the two groups, the HBV positive rate was statistically different between the two groups (P < .05), and the difference of serum HBsAg of infants had statistical significance (P < .05), but the safety of the telbivudine group was not significantly different from that of the control group (P > .05).

CONCLUSION

The application of telbivudine antiviral therapy in the middle and late stage of pregnancy of HBV high-load pregnant women can significantly reduce the HBV DNA level before delivery, reduce the mother-to-child transmission rate of HBV, and have excellent security.

Telbivudine Treatment during Late Pregnancy Prevents Mother-to-Child Transmission of Hepatitis B Virus: A Retrospective Study

PURPOSE

To investigate the efficacy of telbivudine (LdT) in blocking mother-to-child transmission (MTCT) of hepatitis B virus (HBV) during late pregnancy.

METHODS

A total of 651 pregnant women aged 18-40 in Nantong Third People's Hospital and Hospital affiliated to Nantong University with positive hepatitis B surface antigen (HBsAg) and HBV DNA were enrolled between January 2011 and December 2015. Patients with HBV DNA≥10⁶ copies/mL (n=251) received LdT during late pregnancy according to the patients' will, while 136 high viral patients with HBV DNA≥10⁶ copies/mL who did not take LdT therapy and 268 low viral patients with HBV DNA<10⁶ copies/mL served as the controls.

RESULTS

At 7 months and 1 year postpartum, the basal HBV DNA serum level of treated patients declined significantly (P<0.001), while no obvious decline was observed in the untreated high viraemic controls (P<0.05) and untreated low viraemic controls (P<0.05). Only 1 infant (0.4%) in LdT group was HBsAg positive at 7 months, while 14 (5.2%) were in the untreated low viraemic controls (P<0.001) and 15 (11.0%) were in untreated high viraemic controls (P<0.001).

CONCLUSION

For pregnant women with HBV DNA≥10⁶ copies/mL, the use of LdT during late pregnancy could effectively reduce the MTCT rate of HBV.

Is hepatitis B antigen in cord blood an immunotolerogen playing a critical role in the pathogenesis of chronic hepatitis B?

Recently, we showed that infants with or without fetal hepatitis B e antigen (HBeAg) exposure had comparable antibody response to hepatitis B vaccination and proposed that fetal HBeAg exposure appears to not induce immunotolerance to HBV. Here, we summarized the different results on the topic of fetal HBeAg exposure in inducing immunotolerance to HBV nucleocapsid protein, and the evidence to back up that the tendency of high infection rate in infants of HBeAg-positive mothers is more likely associated with higher maternal viral loads and is less likely associated with the fetal HBeAg exposure. We consider that whether fetal HBeAg exposure plays an important role in the pathogenesis of chronic HBV infection remains to be an open question.

Presence of hepatitis B virus markers in umbilical cord blood: Exposure to or infection with the virus?

BACKGROUND

We aimed to clarify whether presence of hepatitis B virus (HBV) markers in cord blood indicates exposure to or infection with HBV.

METHODS

We prospectively recruited HBsAg-positive pregnant women and their neonates 2012 through 2015. All neonates received postnatal immunoprophylaxis. The infants were followed up at 7-14 months of age.

RESULTS

Totally 329 HBsAg-positive pregnant women and 333 neonates were enrolled. No cord blood was anti-HBc IgM positive. A total of 290 (87.1%) neonates were followed up at 7-14 months of age and 6 (2.1%) of them were infected with HBV. Of 146 neonates born to HBeAg-negative mothers, 38 (26.0%) and 30 (20.5%) had detectable HBsAg and HBV DNA in cord blood respectively, but none of 126 infants followed up was infected. Of 187 neonates born to HBeAg-positive mothers, 92 (49.2%) and 79 (42.2%) had detectable HBsAg and HBV DNA in cord blood respectively; 6 (3.7%) of 164 infants followed up were infected. Of seven neonates with HBV DNA > 10⁵ IU/ml in cord blood, four had no infection and three others were infected.

CONCLUSION

Presence of HBsAg and/or HBV DNA, even at high levels, in cord blood just indicates exposure to, but not infection with HBV. Presence of HBV markers in cord blood cannot define intrauterine infection.

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.

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.

Effectiveness of tenofovir or telbivudine in preventing HBV vertical transmission for pregnancy

To evaluate the efficacy and safety of telbivudine (LdT) and tenofovir (TDF) for preventing hepatitis B virus (HBV) vertical transmission for HBV-positive pregnant women.Pregnant women (n = 145) from January 2013 to June 2017 were enrolled when they met inclusion criteria, which included HBV DNA ≥1.0 × 10 copies/mL and increased alanine aminotransferase (ALT) levels. Groups A (n = 58) and B (n = 51) were treated with LdT and TDF, respectively. Group C (n = 36) received no antiviral treatment. All infants were vaccinated with hepatitis B immunoglobulin and HBV vaccine. Vertical transmission of HBV was indicated by the presence of hepatitis B surface antigen (HBsAg) in infants 6 months and 12 months after birth.There is no difference of clinical characteristics of patients among the 3 groups. Serum HBV DNA levels of the 3 groups were similar at baseline (Group A vs. Group B vs. Group C, 7.88 ± 0.65 vs. 7.91 ± 0.75 vs. 7.69 ± 0.53 P = .25). In addition, the after anti-HBV treatment in Groups A and B were significantly decreased. Also, the serum HBV DNA levels in both Groups A and B were lower than that of Group C (P < .01, both). The HBV infection rate in Group A treated with LdT was not different from Group B treated with TDF. The dynamic changes of serum ALT level were similar. ALT levels were similar among the 3 Groups (P = .171), while there is statistically significant difference between A and C, and between B and C before delivery (P < .01). For the infants, there were no significant differences among body weight, height, head circumference, or Apgar score. However, the HBsAg positivity rates of infants in Groups A, B, C at postpartum 24 weeks and 48 weeks was 0%, 0%, and 11.1%, respectively (P < .001).Administration of LdT or TDF to HBV-infected mothers are effective and safe to block mother-to-infant HBV transmission.

Comparison of antibody response to hepatitis B vaccination in infants with positive or negative maternal hepatitis B e antigen (HBeAg) in cord blood: implication for the role of HBeAg as an immunotolerogen

Hepatitis B e antigen (HBeAg) has been considered to cause immunotolerance to hepatitis B virus (HBV) in newborn infants after fetal HBeAg exposure. This study compared anti-HBs responses to hepatitis B vaccination in infants who were born to HBeAg-positive and -negative mothers respectively, to investigate whether fetal HBeAg exposure may induce immunotolerance to HBV. Totally 265 infants who received recommended neonatal immunoprophylaxis against hepatitis B and had no HBV infection were included. Anti-HBs levels were compared between 124 infants with cord blood positive HBeAg and 141 infants with cord blood negative HBeAg at 7-12 months of age. The infants in two groups had similar age at the follow-up (10.0 ± 2.3 vs 10.1 ± 2.3 months, P = 0.590). Overall, 259 (97.7%) of 265 infants achieved anti-HBs levels (mIU/ml) ≥10 and 6 (2.3%) others had anti-HBs <10. Of 124 HBeAg-positive infants at birth, 46.0%, 39.5%, 12.1%, and 2.4% had anti-HBs levels (mIU/ml) ≥1000, 100-999.9, 10-99.9, and <10, respectively. Of 141 HBeAg-negative infants at birth, 35.5%, 48.9%, 13.5%, and 2.1% showed ≥1000, 100-999.9, 10-99.9, and <10, respectively. The proportions of each anti-HBs level between the two groups were comparable (all P > 0.05). Additionally, the distribution of anti-HBs response levels were also comparable in infants with high and low HBeAg levels (P = 0.818). In conclusions, the fetal HBeAg exposure does not inhibit the antibody response to neonatal hepatitis B vaccination. The data suggest that HBeAg appears not inducing immunotolerance to HBV.