Association of chronic hepatitis B virus infection with preterm birth: our experience and meta-analysis

The impact of maternal HBeAg carries status and elevated ALT values on adverse outcomes: a population-based cohort study in 198,049 pregnancies

BACKGROUND

Hepatitis B virus (HBV) infection is a common public health problem, and maternal HBV infection can cause adverse outcomes in both mothers and fetuses. However, the influence of hepatitis B e antigen (HBeAg) serostatus on obstetric outcomes is not well established. This study aims to investigate the prevalence trend of maternal HBV infection in China, and its impact on obstetric outcomes.

METHODS

This retrospective cohort study used data from an established population-based pregnancy registry (REPRESENT) in Xiamen, China. Maternal hepatitis B surface antigen (HBsAg) and HBeAg serostatus were regularly tested at the first antenatal visits. Multivariable regression was conducted to evaluate the impact of maternal HBV infection on maternal and neonatal outcomes.

RESULTS

From January 2015 to March 2019, 198,049 pregnancies were included. The overall prevalence of HBsAg + HBeAg + was 2.26% and has decreased during these years (relative risk 0.59, 95% CI 0.54-0.65). Compared to HBsAg-HBeAg- pregnancies, maternal HBsAg + HBeAg- was associated with a higher risk of intrahepatic cholestasis of pregnancy (ICP) (adjusted odds ratio 3.43, 95% CI 2.94-4.00) and cesarean section (1.04, 1.01-1.08). HBsAg + HBeAg + was further associated with a higher risk of ICP (3.44, 2.64-4.48), fetal distress (1.33, 1.05-1.67), and preterm birth (1.37, 1.04-1.81). In addition, subgroup analysis indicated that abnormal alanine aminotransferase status at the first antenatal visit may exacerbate the impact of maternal HBV infection on maternal and neonatal outcomes.

CONCLUSION

The prevalence of maternal HBsAg + HBeAg + serostatus is still high, but has decreased over time. Given its significant adverse effects, prenatal screening for HBsAg and HBeAg should be performed.

CLINICAL TRIAL NUMBER

Not applicable.

Impact of maternal hepatitis B carrier status on congenital abnormalities: a systematic review and meta-analysis

OBJECTIVES

This study aims to explore whether maternal hepatitis B carrier status is associated with an increased risk of congenital abnormalities.

DESIGN

A systematic review and meta-analysis of observational studies.

DATA SOURCES

PubMed, Embase (Ovid), Scopus, the China National Knowledge Infrastructure (CNKI) and the Wanfang databases.

STUDY SELECTION

Five databases were searched systematically from inception to 7 September 2021. Cohort and case-control studies that investigated the association between maternal hepatitis B virus (HBV) infection and congenital abnormalities were included. This study was conducted according to MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently collected data, as well as assessed risk of bias by using Newcastle-Ottawa Scale. We pooled crude relative risk (cRR) and adjusted OR (aOR) by DerSimonian-Laird random-effects model. Heterogeneity was explored by I ² statistics, Cochran's Q test. Several subgroup analyses and sensitivity analyses were performed.

RESULTS

In total, 14 studies involving 16 205 pregnant women exposed to HBV were included. The pooled cRR of 1.15 (95% CI: 0.92 to 1.45; 14 studies included) showed a marginal but not significant association between maternal HBV-carrier status and congenital abnormalities. However, the pooled aOR of 1.40 (95% CI: 1.01 to 1.93; 8 studies included) indicated that pregnant women with HBV infection might be associated with a higher risk of congenital abnormalities. Subgroup analyses of adjusted data showed a higher pooling cRR or aOR on high prevalence HBV infection populations, as well as studies from Asia and Oceania.

CONCLUSIONS

Maternal hepatitis B carrier status might be at potential risk for congenital abnormalities. The existing evidence was not sufficient to draw a firm conclusion. Additional studies may be warranted to confirm the association.

PROSPERO REGISTRATION NUMBER

CRD42020205459.

Obstetric implications of maternal chronic hepatitis B virus infection

Antenatal screening for hepatitis B surface antigen seropositivity is widely adopted to identify pregnant women with chronic hepatitis B virus (HBV) infection in order to target their newborn infants for combined passive-active neonatal immunization to prevent the maternal-to-child transmission of HBV. It is less certain whether the presence of chronic HBV infection in these largely asymptomatic women could impact their pregnancy outcome. There is now gathering information in the literature, though sometimes conflicting, on the obstetric implications of chronic HBV infection. The conflicting data is most probably related to confounding factors such as the immunological phase of chronic HBV infection, viral genotype and activity, presence of hepatic inflammation and other co-existing liver disorders such as non-alcoholic fatty liver disease, and coinfection with other virus such as hepatitis C virus and micro-organisms, which are usually not examined, but which could have made significant influence on the occurrence of many of the pregnancy complications and adverse fetal and neonatal outcome. For pregnancy complications, the evidence suggests association with increased gestational diabetes mellitus, preterm birth, intrahepatic cholestasis of pregnancy, caesarean delivery, and postpartum haemorrhage, probably increased placental abruption and prelabour rupture of the membranes, and no effect or a reduction in the hypertensive disorders of pregnancy, especially preeclampsia. For perinatal outcome, there may be increased miscarriage and fetal malformations, and increase in both low birthweight and large-for-gestational age/macrosomic infants, as well as increased intrauterine fetal demise/stillbirth and fetal distress. However, most studies have not elaborated on the mechanisms or explanations of many of the adverse outcomes. Taken together, maternal chronic HBV infection increases the risk of adverse obstetric outcome overall, but further prospective studies are warranted to elucidate the reasons and mechanisms of, and with a view to mitigate, these adverse obstetric outcomes.

Prevalence of Hepatitis B Carrier Status and Its Negative Association with Hypertensive Disorders in Pregnancy

Results

In a total cohort of 87889 deliveries over a period of 20 years, the prevalence rate of HBV fell from around 10-11% to around 6-7% in the last 5 years of the study. A negative association between chronic HBV carrier status and all gestational hypertensive disorders could be demonstrated. An apparent protective effect of HBV carrier status was apparently more robust against preeclampsia than gestational hypertension, as the negative association with preeclampsia was consistently observed throughout the study period. A logistic regression model showed that advanced maternal age, multiple pregnancies, obesity, and significant medical disorders were positively correlated with gestational hypertensive disorders, while multiparity and positive HBV carrier status were negatively correlated.

Conclusion

Chronic HBV carrier status appeared to have a protective effect against the development of preeclampsia and gestational hypertension in an endemic area with high HBV prevalence rates.

Pregnancy complicated with hepatitis B virus infection and preterm birth: a retrospective cohort study

Background

We aimed to investigate whether maternal chronic hepatitis B virus (HBV) infection affects preterm birth (PTB) in pregnant women.

Methods

We retrospectively analyzed HBV-infected and non-infected pregnant women attending antenatal care at Fujian Maternity and Child Health Hospital, Fuzhou, China between January 1, 2016 to December 31, 2018. Participants were divided into HBV infection (n = 1302) and control (n = 12,813) groups. We compared baseline data, pregnancy and perinatal complications, and preterm delivery outcomes between groups. Performed multiple logistics regression analysis to adjust for confounding factors. Finally, we compared early PTB outcome between different HBV DNA level groups.

Results

The incidence of preterm birth (gestation less than 37 weeks) was similar between the groups, early preterm birth (gestation less than 34 weeks) were significantly more among the HBV infection group than among the controls (1.6% VS. 0.8%; P = 0.003). After adjusting for confounding factors through logistics regression, HBV infection was found to be an independent early PTB risk factor gestation (adjusted odds ratio 1.770; 95% confidence interval [1.046–2.997]). The incidence of early PTB in < 500 group, 500 ~ 2.0 × 10e⁵ group and > 2.0 × 10e⁵ group was not statistically significant (P = 0.417).

Conclusion

HBV infection is an independent risk factor for early PTB, and the risk did not seem to be influenced by the levels of HBV DNA. Comprehensive programs focusing on pregnant women with HBV infection would reduce the incidence of adverse outcomes.

Chronic maternal hepatitis B virus infection and pregnancy outcome- a single center study in Kunming, China

Background

Chinese population has a high prevalence of chronic hepatitis B virus (HBV) infection, the impact of which on pregnancy outcome remains controversial. A single-center retrospective cohort study was performed in Kunming, a multi-ethnic city in south-western China to examine this issue.

Methods

The singleton pregnancies delivering at ≥28 weeks gestation under our care in 2005–2017 constituted the study cohort. Maternal characteristics and pregnancy outcome were compared between mothers with and without seropositivity for hepatitis B surface antigen (HBsAg) determined at routine antenatal screening.

Results

Among the 49,479 gravidae in the cohort, the 1624 (3.3%) HBsAg seropositive gravidae had a lower incidence of nulliparity (RR 0.963, 95% CI 0.935–0.992) and having received tertiary education (RR 0.829, 95% CI 0.784–0.827). There was no significant difference in the medical history, pregnancy complications, or labor or perinatal outcome, except that HBV carriers had significantly lower incidence of labor induction (RR 0.827, 95% CI 0.714–0.958) and of small-for-gestational age (SGA) infants (RR 0.854, 95% CI 0.734–0.994). On regression analysis, maternal HBV carriage was independently associated with spontaneous labor (aRR 1.231, 95% CI 1.044–1.451) and reduced SGA infants (aRR 0.842, 95% CI 0.712–0.997).

Conclusions

Our 3.3% prevalence of maternal HBV infection was around the lower range determined in the Chinese population. The association with spontaneous labor and reduced SGA infants could have helped to promote the perpetuation of the infection through enhanced survival of the offspring infected at birth, thus explaining the high prevalence in the Chinese population.

A systematic review of the maternal and neonatal complications in hepatitis B infection

The association between hepatitis B virus (HBV) infection and maternal, obstetric and newborn outcomes remains controversial, as previous studies have reported conflicting and inconsistent results on the matter. The aim was to investigate whether HBV infection increases the risk of maternal, obstetric and newborn complications. We conducted a systematic literature review, according to PRISMA statement guidelines. Studies were eligible for inclusion if they were observational cohort, case-control or cross-sectional studies, comparing maternal, obstetric or newborn complications in HBV-infected and uninfected pregnant women. PubMed was searched for published literature in English, with no date restrictions, using combinations of keywords. The titles and abstracts were independently screened for eligibility by three authors. Two authors assessed the quality of each included study and no meta-analysis was performed. We retrieved 275 records and included 15 papers. The methodological and statistical heterogeneity as well as a great variation on the types of maternal, obstetric and newborn complications studied did not allow quantitative analysis of results and conclusions about the level of evidence. Seven studies are of good quality, which makes their results more reliable. Three of them revealed that maternal HBV infection increased the risk of miscarriage, preterm birth, pregnancy-induced hypertension, fetal distress and macrosomia. These three studies were performed in China and the one with the largest number of participants only included women from rural areas. Larger, more robust, well-designed prospective cohort studies are needed. These must include adjusted estimates for confounding factors, such as other possible complications determinants, like the antenatal care quality.

Maternal hepatitis B infection status and adverse pregnancy outcomes: a retrospective cohort analysis

PURPOSE

To investigate the association between maternal HBsAg-positive status and pregnancy outcomes.

METHODS

The study enrolled women with singleton pregnancies who delivered during January-December 2018. Data of maternal demographics and main adverse pregnancy outcomes were collected from the institutional medical records and analyzed by univariate and multivariate logistic regression models to determine the association between maternal HBV markers (HBsAg/HBeAg/HBV-DNA loads status) and adverse pregnancy outcomes.

RESULTS

Total 1146 HBsAg-positive and 18,354 HBsAg-negative pregnant women were included. After adjusting for potential confounding variables, maternal HBsAg-positive status was associated with a high risk of gestational diabetes mellitus (GDM) [adjusted odds ratio (aOR) = 1.24; 95% confidence interval (CI) 1.07-1.43], intrahepatic cholestasis of pregnancy (ICP) (aOR = 3.83; 95% CI 3.14-4.68), preterm birth (aOR = 1.42; 95% CI 1.17-1.72), and neonatal asphyxia (aOR = 2.20; 95% CI 1.34-3.63). Further, higher risks of ICP and neonatal asphyxia remained with either HBeAg-positive status (aOR = 1.64; 95% CI 1.10-2.44; aOR = 3.08; 95% CI 1.17-8.00) or high HBV-DNA load during the second trimester (aOR = 1.52; 95% CI 1.06-2.35; aOR = 4.20; 95% CI 4.20-15.83) among HBsAg-positive pregnant women.

CONCLUSION

Women with maternal HBsAg-positive status may have increased risks of GDM, ICP, preterm birth, and neonatal asphyxia; furthermore, the risks of ICP and neonatal asphyxia were higher in women with HBeAg-positive status and a high HBV-DNA load during the second trimester among the HBsAg-positive pregnant women, implying that careful surveillance for chronic HBV infection during pregnancy is warranted.

Hepatitis B - chronic carrier status and pregnancy outcomes: An obstetric perspective

Antenatal screening for hepatitis B surface antigen (HBsAg) only identifies women with hepatitis B virus (HBV) infection for neonatal immunoprophylaxis. It does not reflect the phase of chronic infection, viral genotype and activity, hepatic inflammation, or other co-existing liver disorders. Coinfection with other viruses and micro-organisms may also be present. These factors in various combinations can impact pregnancy outcomes, and they are probably responsible for the conflicting literature on this issue. Pregnancy complications may interact with maternal HBV infection and hepatitis flares, leading to serious and lethal complications. Hepatitis flares are common especially postpartum, and they are unpredictable and unpreventable with antiviral treatment. Evidence on the association between HBsAg seropositivity with gestational diabetes mellitus, preterm birth, increased foetal growth, and reduced pregnancy hypertensive disorders is stronger than other adverse pregnancy outcomes. Baseline assessment of liver function, and viral markers and activity, can delineate the truly high-risk pregnancies for close monitoring.

Maternal age and educational level modify the association between chronic hepatitis B infection and preterm labor

BACKGROUND

Few studies have investigated whether maternal age and education level modify the association of chronic hepatitis B virus (HBV) infection with preterm labor. We hypothesized that the association of HBV infection with preterm labor is modified by maternal age and education level.

METHODS

A retrospective cohort study was conducted on the HBsAg-positive and HBsAg-negative pregnant women delivered from June 2012 to August 2017 at Wuhan Medical Care Center for Women and Children, Wuhan, China. A multivariate regression model was used in this study.

RESULTS

This study included 2050 HBsAg-positive pregnant women and 2050 HBsAg negative women. In the stratified analyses, positive HBsAg status was associated with the increased risk of preterm labor in women aged < 30 years, having low educational level, with an odds ratio of 1.65(95% CI 1.07-2.54) and 2.59(95% CI 1.41-4.76), respectively. Breslow-Day test showed that there existed significant differences in the ORs for HBsAg carriage across each stratum of maternal age (p = 0.023), educational level (p = 0.002). After adjusting other co-variables, we observed maternal HBV infection (OR 1.60, 95% CI 1.03-2.49) was still associated with risk of preterm labor in pregnancy women with age < 30. Similarly, the significant association of HBV infection (OR 2.49, 95% CI 1.34-4.63) with preterm labor remained in low educated women.

CONCLUSIONS

Our results indicated that HBV infection was associated with high risk of preterm labor, but maternal age and educational level could modify the association between HBV infection and preterm labor.

Liver Dysfunction during Pregnancy and Its Association of With Preterm Birth in China: A Prospective Cohort Study

BACKGROUND

Liver dysfunction is common in pregnancy but its association with adverse pregnancy outcomes such as preterm birth (PTB) remains unclear.

METHODS

A prospective cohort of HBV-infected or uninfected pregnant women attending antenatal care was recruited at Nantong Maternal and Child Health Hospital between January 1, 2012, and June 30, 2016. Liver function tests (LFTs) were monitored through pregnancy. The primary outcomes were PTB and very PTB (delivery prior 37 and 32weeks' gestation respectively). Poisson regression was used to estimate adjusted risk ratios (RR) for women with HBV infection and LFT abnormalities.

RESULTS

Among 36,755 pregnant women (1,113 HBV carriers and 35,642 non-HBV subjects), 3,519 (9.57%) had abnormal LFTs. The commonest cause for liver dysfunction during pregnancy was non-alcoholic fatty liver diseases (NAFLD, 51.3%). Abnormal aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT) and two folds upper limit of normal total bilirubin (RR and 95%CI: 2.73, 1.30-5.76; 2.24, 1.35-3.31; 2.01, 1.22-3.31 respectively), rather than HBsAg positivity, were identified as independent risk factors for preterm birth. Besides, GGT abnormality was associated with increased risk of very PTB.

CONCLUSIONS

We suggest that surveillance of LFTs among pregnant women should be warranted, given the increased risk of PTB.