Maternal hepatitis B virus infection and risk of preterm birth in China

Hepatitis B virus clinical and virologic characteristics in an HIV perinatal transmission study in sub-Saharan Africa

OBJECTIVES

To describe the clinical and virologic characteristics of HIV-HBV coinfection, including the predictors of high maternal HBV viral load in pregnant women with HIV in sub-Saharan Africa (SSA).

METHODS

HPTN 046 was a HIV perinatal transmission clinical trial evaluating infant nevirapine vs. placebo. Women-infant pairs ( n  = 2016) were enrolled in SSA from 2007 to 2010; 1579 (78%) received antiretrovirals (ARV). Maternal delivery samples were retrospectively tested for hepatitis B surface antigen (HBsAg), and if positive, were tested for hepatitis B e antigen (HBeAg) and HBV viral load (VL). High HBV VL was defined as ≥10 6  IU/ml.

RESULTS

Overall, 4.4% (88/2016) had HBV co-infection, with geographic variability ranging from 2.4% to 8.7% ( P  < 0.0001); 25% (22/88) were HBeAg positive with prevalence in countries ranging from 10.5% to 39%. Fifty-two percentage (40/77) of those with HBV received ARV, the majority (97%) received 3TC as the only HBV active agent. HBeAg positivity was associated with high maternal HBV VL, odds ratio (OR) 37.0, 95% confidence interval (CI) 5.4-252.4. Of those with high HBV VL, 40% (4/10) were receiving HBV active drugs (HBV-ARV). HBV drug resistance occurred in 7.5% (3/40) receiving HBV-ARV.

CONCLUSIONS

In SSA, HBV co-infection is common in pregnant women with HIV. HBsAg and HBeAg prevalence vary widely by country in this clinical trial cohort. HBeAg is a surrogate for high HBV viral load. HBV drug resistance occurred in 7.5% receiving HBV-ARV with lamivudine as the only HBV active agent. These findings reinforce the importance of HBsAg screening and early treatment with two active agents for HBV.

The cell‐free DNA virome of 108,349 Dutch pregnant women

OBJECTIVE

Viral infections during pregnancy are a major health concern to mother and fetus. By repurposing cell-free Non Invasive Prenatal Testing (NIPT) sequencing data, we investigated prevalence and abundance of viral DNA in a cohort of 108,349 pregnant women.

METHOD

Cell-free DNA (cfDNA) sequencing reads that did not map to any of the human chromosomes or mitochondrial DNA of the human reference genome build GRCh38 were aligned to 224 DNA viruses selected from the NCBI refseq viral database.

RESULTS

In total 443,665 reads of viral origin were detected across 42,273 samples representing 165 viral species. Several are known to be potentially harmful during pregnancy and/or childbirth, including Cytomegalovirus, Parvovirus B19 and Hepatitis B. Viral sequences were mostly detected at very low abundance. However, several cases had exceptionally high viral loads for Parvovirus B19, Hepatitis B and others. We found statistically significant associations between presence of viral DNA and gestational age, maternal age, fetal fraction, cfDNA concentration and others.

CONCLUSION

We demonstrate the feasibility to detect viral DNA from typical genome-wide NIPT cfDNA sequencing and describe the main characteristics of the viral DNA in our cohort. Our dataset of detected viral sequence reads is made publicly available to guide future clinical implementations.

Clinically relevant DNA viruses in pregnancy

Infections by DNA viruses during pregnancy are associated with increased health risks to both mother and fetus. Although not all DNA viruses are related to an increased risk of complications during pregnancy, several can directly infect the fetus and/or cause placental dysfunction. During NIPT analysis, the presence of viral DNA can be detected, theoretically allowing screening early in pregnancy. Although treatment options are currently limited, this might rapidly change in the near future. It is therefore important to be aware of the potential impact of these viruses on feto-maternal health. In this manuscript we provide a brief introduction into the most commonly detected DNA viruses in human cell-free DNA sequencing experiments and their pathogenic potential during pregnancy. This article is protected by copyright. All rights reserved.

Viral Infections During Pregnancy: The Big Challenge Threatening Maternal and Fetal Health

Viral infections during pregnancy are associated with adverse pregnancy outcomes, including maternal and fetal mortality, pregnancy loss, premature labor, and congenital anomalies. Mammalian gestation encounters an immunological paradox wherein the placenta balances the tolerance of an allogeneic fetus with protection against pathogens. Viruses cannot easily transmit from mother to fetus due to physical and immunological barriers at the maternal-fetal interface posing a restricted threat to the fetus and newborns. Despite this, the unknown strategies utilized by certain viruses could weaken the placental barrier to trigger severe maternal and fetal health issues especially through vertical transmission, which was not fully understood until now. In this review, we summarize diverse aspects of the major viral infections relevant to pregnancy, including the characteristics of pathogenesis, related maternal-fetal complications, and the underlying molecular and cellular mechanisms of vertical transmission. We highlight the fundamental signatures of complex placental defense mechanisms, which will prepare us to fight the next emerging and re-emerging infectious disease in the pregnancy population.

Maternal chronic hepatitis B virus infection and the risk of preterm birth: A retrospective cohort analysis in Chinese women

The association between different clinical states of chronic HBV infection and preterm birth (PTB) is still controversial. A retrospective cohort study among 57,386 pregnant women was conducted to examine the impact of chronic HBsAg positive, both HBsAg and HBeAg positive, and chronic active hepatitis on pregnancy complications related to the overall PTB and its subtypes (spontaneous and iatrogenic). A total of 54,245 pregnancies were included in the final study cohort, among which 2,151(4.0%) pregnant women were HBsAg positive. The PTB rate was 6.0% (129/2151) for HBV-infected women while 4.5% (2319/52094) for those not. Compared with women not infected with HBV, multivariable-adjusted analyses showed HBV-infected women had a 33% higher risk of overall PTB (aRR 1.33 95%CI, 1.11-1.60), a 27% higher risk of spontaneous PTB (aRR 1.27, 95% CI, 1.02-1.57) and a 50% higher risk of iatrogenic PTB (aRR 1.50, 95%CI, 1.07-2.11). The PTB rate was 8.9% (35/395) for both HBsAg and HBeAg-positive women and 16.2% (22/136) for women with active chronic hepatitis. Multivariable-adjusted analyses showed women who were both HBsAg and HBeAg positive had a 47% higher risk of overall PTB (aRR 1.47, 95%CI, 1.04-2.09), a 2.03 times higher risk of spontaneous PTB (aRR 2.03, 95%CI, 1.38-2.99) and a 32% higher risk of iatrogenic PTB (aRR 1.32, 95%CI, 0.62-2.81), while women with chronic active hepatitis had a 3.84 times higher risk of overall PTB (aRR 3.84, 95%CI, 2.42-6.10), a 3.88 times higher risk of spontaneous PTB (aRR 3.88, 95%CI, 2.32-6.45) and a 3.01 times higher risk of iatrogenic PTB (aRR 3.01, 95%CI, 1.22-7.44). Different maternal clinical states of chronic HBV infection are independently associated with an increased risk of overall PTB and its subtypes (spontaneous and iatrogenic).

Hepatitis B Virus Infection in Pregnancy: Immunological Response, Natural Course and Pregnancy Outcomes

This review aimed to provide an update on the impact of pregnancy on the natural course of hepatitis B virus (HBV) infection and also on the impact of HBV infection on adverse pregnancy outcomes, including mother-to-child transmission (MTCT). For the literature review, original research articles, review articles, and guidelines were narratively reviewed and comprehensively validated. The databases of PubMed, EMBASE, and CINAHL were carefully searched for articles in English on topics related to HBV infection, pregnancy, and vertical transmission from 1960 to May 2021. Immunological changes during pregnancy such as suppression of Th1 response and induction of Th2 immunity lead to an impaired immune reaction to HBV and stimulate viral activity along with the reduction of CD8 T cells to escape immune detection. The impact of pregnancy on the natural course of chronic HBV infection seems to be minimal, while pregnancy can increase morbidity and mortality in the case of advanced HBV hepatitis or cirrhosis. Importantly, hepatitis flare or alanine aminotransferase (ALT) flare can occur during pregnancy and is more common during the postpartum period due to the interaction between HBV and the immune response. Interestingly, the impact of HBV infection on adverse pregnancy outcomes is more serious than ever thought. Updated evidence indicates that pregnancies with chronic HBV infection increase the risk of preterm birth and gestational diabetes, especially in cases of positive hepatitis e antigen (HBeAg).

Chronic hepatitis B in pregnant women: Current trends and approaches

Chronic hepatitis B (CHB) is a significant public health problem worldwide. The aim of the present review is to summarize the actual trends in the management of CHB in pregnant women. The prevalence of hepatitis B virus (HBV) infection in pregnant women is usually comparable to that in the general population in the corresponding geographic area. All women have to be screened for hepatitis B surface antigen (HBsAg) during pregnancy. Additional examinations of pregnant women with CHB may include maternal hepatitis B e antigen, HBV viral load, alanine aminotransferase level, and HBsAg level. The management of pregnancy depends on the phase of the HBV infection, which has to be determined before pregnancy. In women of childbearing age with CHB, antiviral therapy can pursue two main goals: Treatment of active CHB, and vertical transmission prevention. During pregnancy, tenofovir is the drug of choice in both cases. A combination of hepatitis B immunoglobulin and vaccine against hepatitis B should be administered within the first 12 h to all infants born to mothers with CHB. In such cases, there are no contraindications to breastfeeding.

Maternal HBV Viremia and Association With Adverse Infant Outcomes in Women Living With HIV and HBV

BACKGROUND

There is limited information on perinatal outcomes in HIV-hepatitis B virus (HBV) coinfection.

METHODS

HIV Prevention Trials Network (HPTN) 046 was a randomized double-blind placebo-controlled trial of perinatal transmission that evaluated 6 months of infant nevirapine versus placebo among breast-fed infants. Women living with HIV and their infants enrolled in sub-Saharan Africa from 2007 to 2010; 78% received antiretroviral therapy (ART). Maternal samples were tested for hepatitis B surface antigen (HBsAg). High and low HBV viral load (VL) was defined as ≥106 IU/mL and <106 IU/mL. The association between HIV-HBV coinfection and maternal and infant outcomes was assessed using multivariate (MV) logistic and Cox regression.

RESULTS

Among 2025 women, 88 (4.3%) had HBV. HIV-HBV women with high HBV VL had lower median CD4, versus HIV alone or HIV-HBV women with low HBV VL [320, 490 and 434 cells/mm3, respectively (P < 0.007)]. In MV analysis, adjusted for maternal CD4, age and maternal ART, infants born to women with high HBV VL were more likely to be low birth weight (LBW), versus HIV+/HBV- and low HBV VL women: [30% (3/10) vs. 10% (194/1953) vs. 6% (5/78), respectively, P = 0.03). High HBV VL was associated with HIV perinatal transmission [(hazard ratio 6.75 (95% confidence interval (CI): 1.86 - 24.50)]. There was no impact on infant mortality or maternal outcomes at 18 months.

CONCLUSIONS

In HIV-HBV women, high HBV viral loads increase the risk of LBW and potentially HIV perinatal transmission. Reduction of antepartum HBV viremia may have beneficial effects beyond the prevention of HBV perinatal transmission.