Investigating the association between socio-economic position and
      stillbirth in Brazil and the UK
Creators: name: Jones, Abbie
Publisher: name: Lancaster University
Year: 2019

description: Stillbirths are under-researched in comparison to other child health
      outcomes. They rarely appear in national health targets or commitments,
      despite being an immense global burden with 2.6 million cases annually.
      Using routine national datasets, this thesis compares the social
      disparities in stillbirth rates within and between the UK and Brazil as a
      high-income and middle-income country, respectively.
      
      The role of socio-economic position (SEP) in the likelihood of stillbirth,
      and how it is mediated through behavioural, health and pregnancy-related
      factors, is clarified comprehensively reviewed and a new conceptual model
      constructed. A comprehensive review of perinatal health policies in the UK
      and Brazil showcases Brazil’s evolution as a major emerging economy from a
      public health perspective, in relation to the UK.
      
      Analysis of the UK required two separate datasets; aggregated birth counts
      from ONS for England and Wales, and Scotland’s Maternity and Neonatal
      Linked Database (MNLD). In England and Wales, higher stillbirth rates were
      associated with areas containing higher proportions of ethnic minority
      babies, after accounting for maternal age and other confounders. Whilst
      the data for England and Wales was limited to an aggregate analysis, the
      comprehensive Scottish data allowed a mediation analysis which was applied
      to the MNLD to investigate more fully the causal pathways between SEP and
      stillbirth. While socio-demographic factors such as maternal age,
      ethnicity, and marital status were found to have no direct effect on
      stillbirth risk, their mediating influence on gestational age and birth
      weight played a vital role in the cause of stillbirth.
      
      Brazil’s National Household Sample Survey (PNAD) was analysed to determine
      the primary socioeconomic risk factors associated with stillbirth. The
      main challenge presented by the data was that the birth outcomes were
      presented as counts - the numbers of live births and stillbirths had by
      each woman. By converting the observed live birth and stillbirth counts
      for each woman into lists of possible birth sequences, and deriving the
      appropriate likelihood function, this thesis was able to perform
      regression on a new binary outcome for live birth verses stillbirth. Women
      with lower levels of education and inadequate household goods and services
      had a higher risk of stillbirth. Analysis of stillbirth rates based on
      women’s lifetime birth histories revealed some counter-intuitive
      relationships between geographic and social factors and stillbirth, which
      were distorted by high parity among disadvantaged women.
      
      Data and methodologies were too different to compare the magnitudes of
      variable effects between countries. Whilst our new methodological
      approaches have allowed more sophisticated analyses than have been
      previously possible, ultimately, this thesis has highlighted the strengths
      and limitations that different data sources allow in describing
      stillbirths globally. Without more comprehensive monitoring and better
      defined outcomes, countries will struggle to see the full picture. As we
      have shown aggregate level data are inadequate for public health
      monitoring in England and Wales, and restrictions on data availability
      prohibit informative individual-level analyses. Looking to the future the
      Scottish data has shown that the gold standard of data linkage is both
      viable and recommended for 21st century public health management.