Neonatal mortality in 2001-2017 in France: A cause-specific and spatiotemporal analysis.

Background: In France, the infant mortality rate had a long period of decline, but it stopped decreasing after 2010 and then rose. Neonatal mortality is a large part of infant mortality. The aim of this study was thus to describe its main changes, by cause of death and gestational age, and the main changes in socio-spatial distribution, from 2001 to 2017.

Methods: For this purpose, we investigated data on neonatal deaths reported in France from 2001 to 2017. Crude, cause-specific and gestational age-specific neonatal mortality rates were computed and an ecological analysis, according to several contextual factors at commune level, was performed using quasi-Poisson regressions.

Results: The average neonatal mortality rate was 2.42 per 1000 live births in France during the study period, showing an increase from 2011 onwards. This increase was mostly related to perinatal conditions and more births at very low gestational age. Gestational age-specific neonatal mortality rates did not increase during the period. The analysis of socio-spatial factors showed increased mortality rates in large cities, deprived areas and cities with higher percentages of migrants.

Conclusion: This study suggests that a shift in the distribution of gestational age at birth toward low gestational ages may have contributed to the rise in neonatal mortality in France. Furthermore, there is notable spatial heterogeneity in neonatal mortality. Nevertheless, this observation poorly explains the specificity of the high level and recent upsurge in infant mortality in France, in contrast to its European counterparts.