title: [Perinatal mortality assessment in native and immigrant women: influence of exhaustiveness and quality of the registries].
abstract: OBJECTIVE
  To analyze the exhaustiveness and reliability of the data on perinatal mortality in two Spanish registries, namely, the National Statistics Institute and the Perinatal Mortality Registry of the Valencian Community and to calculate and compare the perinatal mortality rate (PMR) and its components in native and immigrant women, based on the cases reported to both registries in 2005 and 2006.
  
  
  METHODS
  Perinatal mortality and its components were defined according to the World Health Organization's criteria. The magnitude of underreporting was calculated by taking into account the frequencies and percentages of deaths not declared for 2005-2006. Rates and their 95% confidence intervals were calculated and compared between native and immigrant women using data from both registries.
  
  
  RESULTS
  Fetal and neonatal deaths were substantially underreported in the National Statistics Institute compared with the Perinatal Mortality Registry of the Valencian Community. Moreover, in the National Statistics Institute, some neonatal deaths among the offspring of immigrant women were misclassified as being of Spanish nationality. These two factors distorted the proportion of fetal and neonatal deaths in immigrant women, giving rise to an underestimation of the PMR and its components, since the rates obtained from the Perinatal Mortality Registry of the Valencian Community were higher in immigrant than in Spanish women, particularly among east-European and sub-Saharan women.
  
  
  CONCLUSIONS
  Our results indicate that both registries are complementary. However, the Perinatal Mortality Registry of the Valencian Community was found to be more exhaustive and to have greater reliability. Our results also suggest the importance of monitoring trends in PMR in the immigrant population in Spain.
authors.affiliation: CIBER en Epidemiología y Salud Pública (CIBERESP), Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Río Sánchez
authors.forename: Susana
authors.initials: S
authors.lastname: Bosch Sánchez
authors.forename: Adela
authors.initials: A
authors.lastname: Castelló Pastor
authors.forename: Aurora
authors.initials: A
authors.lastname: López-Maside
authors.forename: Carmen
authors.initials: C
authors.lastname: García Senchermes
authors.forename: Oscar
authors.initials: O
authors.lastname: Zurriaga Llorens
authors.forename: Sol
authors.initials: S
authors.lastname: Juárez
authors.forename: Marisa
authors.initials: M
authors.lastname: Rebagliato Ruso
authors.forename: Francisco
authors.initials: F
authors.lastname: Bolúmar Montrull
mesh_terms: D004641:Emigration and Immigration; D005260:Female; D005313:Fetal Death / Q000453:epidemiology*; D006801:Humans; D054238:Perinatal Mortality / Q000639:trends*; D012042:Registries / Q000592:standards* / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D013030:Spain