Modifiable Risk Factors Associated with Adverse Perinatal Outcomes in Bangladesh

Background Globally, perinatal mortality accounts for approximately five million deaths (2.6 million stillbirths and 2 million early neonatal deaths) every year. Further, low birthweight which is a major adverse perinatal outcome constitutes more than 20 million births every year. Approximately 97%-99% of these adverse perinatal outcomes occur in low- and middle-income countries including Bangladesh. In Bangladesh, the burden of perinatal mortality remains high at 44 deaths per 1,000 pregnancies and low birthweight accounts for approximately 36% of births every year, yet many modifiable factors associated with these adverse perinatal outcomes remain under-investigated in the country. Aim and objectives The primary aim of this thesis was to gain a deeper understanding of modifiable risk factors contributing to adverse perinatal outcomes in Bangladesh. The specific objectives included investigating the association between polluting cooking fuels and perinatal mortality (stillbirth and early neonatal mortality) in Bangladesh; examining the effect of short and long birth intervals on adverse perinatal outcomes (first-day neonatal mortality, early neonatal mortality and small birth size) in Bangladesh; exploring community perceptions on birthweight and care practices for low birthweight infants in Bangladesh; and identifying modifiable socio-cultural factors influencing women’s early and adequate utilisation of antenatal care in rural Bangladesh. Methods In this thesis, both quantitative and qualitative methods were used. For the quantitative analyses (studies I and II), data were derived from the Bangladesh Demographic and Health Surveys (BDHS) from the years 1996-1997, 1999-2000, 2004, 2007, 2011 and 2014. Bivariate and multivariable analyses were conducted to obtain the crude and adjusted odds ratio (aOR) respectively. Wald test was used to assess statistical significance with a 95% confidence interval (CI). The ‘svy’ command was used in all the analyses to calculate the weighted values in order to adjust for the clustering effect and sample stratification. Data for the qualitative analyses (studies III and IV) were derived from the results of in-depth interviews, key-informant interviews and focus group discussions conducted in two rural settings of Bangladesh. In total, 32 in-depth interviews were conducted with 11 pregnant women, 12 recently delivered women, four husbands whose wives were pregnant or had a recent birth, and five mothers-in-law whose daughters-in-law were pregnant or had a recent birth. Two focus group discussions were conducted with husbands with eight participants in each and four key-informant interviews were conducted with community health workers. Thematic analysis was used to analyse the data. Results Study I included in this thesis examined the association between polluting cooking fuels (kerosene, coal/lignite, charcoal, wood, straw/shrubs/grass, agricultural crop and animal dung) and perinatal mortality (stillbirth and early neonatal mortality) using BDHS data from the years 2004, 2007, 2011, and 2014. In the multivariable analysis, maternal exposure to polluting fuels compared with exposure to clean fuels (electricity, liquefied petroleum gas, natural gas, and biogas) was associated with early neonatal mortality (aOR: 1.46, 95% CI: 1.01, 2.10); however, no association was found for stillbirth (aOR: 1.25, 95% CI: 0.85, 1.84). While examining the impact of each type of polluting fuels on perinatal mortality, the association with perinatal mortality varied by types of polluting fuels. Maternal exposure to agricultural crop waste as the main fuel was associated with increased odds of both stillbirth (aOR: 1.76, 95% CI: 1.10, 2.80), and early neonatal mortality (aOR: 1.78, 95% CI: 1.13, 2.80). Maternal exposure to wood as the main fuel posed greater odds for early neonatal mortality (aOR: 1.52, 95% CI: 1.04, 2.21). Using polluting cooking fuels in an indoor kitchen was associated with four times higher odds of stillbirth (aOR: 4.12, 95% CI: 1.49, 11.41). Study II of this thesis was an investigation of the effect of short (<36 months) and long (≥60 months) birth intervals on adverse perinatal outcomes including first-day neonatal death, early neonatal death and small birth size using BDHS data from the years 1996-1997, 1999-2000, 2004, 2007, 2011 and 2014. In the multivariable analysis, infants with a birth interval of