Maternal Hepatitis B Infection Burden, Comorbidity and Pregnancy Outcome in a Low-Income Population on the Myanmar-Thailand Border: A Retrospective Cohort Study

Hindawi Journal of Pregnancy Volume 2019, Article ID 8435019, 11 pages https://doi.org/10.1155/2019/8435019 Research Article Maternal Hepatitis B Infection Burden, Comorbidity and Pregnancy Outcome in a Low-Income Population on the Myanmar-Thailand Border: A Retrospective Cohort Study Marieke Bierhoff,1,2 Chaisiri Angkurawaranon ,3 Aung Myat Min,1 Mary Ellen Gilder,1 Nay Win Tun,1 Arunrot Keereevijitt,1 Aye Kyi Win,1 Elsi Win,1 Verena Ilona Carrara,1,4,5 Tobias Brummaier,1,4,5 Cindy S. Chu,1 Laurence Thielemans,1,6 Kanlaya Sriprawat,1 Borimas Hanboonkunupakarn,7 Marcus Rijken,8 François Nosten,1,9 Michele van Vugt,2 and Rose McGready1,9 1 Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Mae Sot 63110, Thailand Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands 3 Department of Family Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand 4 Department of Medicine, Swiss Tropical and Public Health Institute, Basel, Switzerland 5 Faculty of Medicine, University of Basel, Basel, Switzerland 6 Neonatology-Pediatrics, Cliniques Universitaires de Bruxelles-Hôspital Erasme, Université Libre de Bruxelles, Brussels, Belgium 7 Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok 10400, Thailand 8 Utrecht University Medical Centre, Utrecht, Netherlands, and Julius Centre Global Health, Utrecht 3584 CX, Netherlands 9 Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine Research Building, University of Oxford, Oxford OX3 7FZ, UK 2 Correspondence should be addressed to Chaisiri Angkurawaranon; Received 14 November 2018; Accepted 21 January 2019; Published 25 February 2019 Academic Editor: Helena Strevens Copyright © 2019 Marieke Bierhoff et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Objectives. Hepatitis B virus (HBV) was believed to have minimal impact on pregnancy outcomes apart from the risk of perinatal transmission. In more recent years, there have been reports of adverse associations, most consistently preterm birth (PTB), but this is in the context of high rates of caesarean section. The aim of this study was to explore the association of HBV on pregnancy outcomes in marginalized, low-income populations on the Myanmar-Thailand border. Methods. HBsAg positive (+) point of care rapid detection tests results were confirmed by immunoassays. Women with a confirmed HBsAg status, HIV- and syphilisnegative at first antenatal care screening, singleton fetus and known pregnancy outcome (Aug-2012 to Dec-2016) were included. Logistic regression analysis was used to evaluate associations between HBV group (controls HBsAg negative, HBsAg+/HBeAg, or HBsAg+/HBeAg+) and pregnancy outcome and comorbidity. Results. Most women were tested, 15,046/15,114 (99.6%) for HBV. The inclusion criteria were not met for 4,089/15,046 (27.2%) women due mainly to unavailability of pregnancy outcome and nonconfirmation of HBsAg+. In evaluable women 687/11,025 (6.2%) were HBsAg+, with 476/11,025 (4.3%) HBsAg+/HBeAg- and 211/11,025 (1.9%) were HBsAg+/HBeAg+. The caesarean section rate was low at 522/8,963 (5.8%). No significant associations were observed between pregnancy comorbidities or adverse pregnancy outcomes and HBV status. Conclusions. The results highlight the disease burden of HBV in women on the Myanmar-Thailand border and support original reports of a lack of significant associations with HBsAg+ irrespective of HBeAg status, for comorbidity, and pregnancy outcomes in deliveries supervised by skilled birth attendants. 2 1. Introduction Hepatitis B virus (HBV) infection is hyperendemic in Southeast Asia. It is assumed that about 75-80% of the estimated 240 million HBV carriers globally live in this region [1]. In endemic areas in Southeast Asia and Africa, where the most significant route of transmission is from mother to child (MTCT) or from child to child, up to 90% of infected persons have a chronic course [2, 3]. In mothers who are HBeAg positive (+) and at highest risk of transmitting HBV, Hepatitis B immunoglobulins (HBIG) should be routinely provided if women give birth or in the case of homebirth the infant should be presented to a clinic where this specialized vaccination is available before 72 hours of life [4, 5]. However, this prophylactic regimen is often not given in low-income countries (LIC) because of cost, complexity of production, and need for a reliable cold chain [6]. Health care systems in LIC struggle to respond to the significant burden of communicable infections in pregnancy and routine HBV testing is not always available [7]. For many years it has been thought that maternal HBV infection had no influence on pregnancy outcomes [8], but published evidence particularly from the last 5 years suggests there may be an impact of HBsAg+ irrespective of HBeAg status on preterm birth, among other outcomes [9– 14]. Preterm birth (PTB) has been highlighted as a major finding in three [10, 13, 14] of these publications. While there is theoretical evidence to support an increased risk of PTB from chronic liver disease due to increased cytokine production from inflammation [15], the PTB data remains largely observational and at risk of bias. Sources of bias could include inability to control use of other (social) drugs, other (subclinical) infections, e.g., Hepatitis C virus, poor gestational age assessment, and obstetrician preference for caesarean section [16], a known iatrogenic risk factor for PTB. The leading countries contributing to data on pregnancy outcome according to HBV status are the USA and Europe who have low HBV prevalence and China with a moderate to high HBV prevalence; USA and China have high rates of caesarean section [17]. Controlling the indication for caesarean section in data extraction for systematic review and meta-analysis can be problematic as country policy and local hospital practice may not confer. HBsAg+, irrespective of HBeAg status, was associated with miscarriage in one study [11] where more than 20,000 women were registered since the first trimester. Other studies have not found associations between HBsAg+ (irrespective of HBeAg status) and pregnancy outcomes and pregnancy morbidity including premature rupture of membranes, preeclampsia, gestational diabetes mellitus (GDM), increased risk of prematurity, lower birth weight, small- or large for gestational age or antepartum hemorrhage [10–12]. A high burden of HBV (8.3%) infection in refugees and migrant pregnant women on the Myanmar-Thailand border as well as factors associated with infection (age over 25 years and Karen heritage) for the period of August 2012 and April 2014 has been reported [18]. In this retrospective study we aimed to examine the (...truncated)