41 - Social inequalities in infant mortality related to congenital anomalies: a population-based study in Paris

Publication Number: 4040.41

Bermet Amirova, Inserm, Paris, Ile-de-France, France; Jennifer Zeitlin, Inserm, Paris, Ile-de-France, France; Isabelle Monier, INSERM, Paris, Ile-de-France, France; Nathalie Lelong, INSERM, Paris, Ile-de-France, France

Background: Infant mortality has recently increased in France, with more marked increases in deprived urban areas. Congenital anomalies (CA) are a major cause of infant mortality and may contribute to these trends. Despite universal coverage for prenatal screening in France, disparities in access to care may exist.

Objective: This study examined socio-spatial inequalities in infant mortality linked to CA in Paris and its antenatal detection.

Design/Methods: Data on all live births (≥22 weeks) and infant deaths ( < 1 year) with CA came from the Paris congenital anomaly registry (remaPAR) for 2019-2023. Maternal addresses were geocoded to the smallest census unit and linked to the P-FDep deprivation index based on census area socioeconomic data. Crude odds ratios (OR) were estimated for risks of live birth and infant death associated with CA across deprivation quintiles using a census-based control population of infants residing in Paris. We further explored whether the CA was detected antenatally.

Results: Between 2019 and 2023, 2,539 live births with CA were recorded. The proportion of cases increased with area deprivation, from 16.8% in the least to 24.0% in the most deprived quintile (OR=1.46 (95% confidence intervals (CI): 1.29-1.66)). Infant deaths associated with CA ranged from 9.9% to 30.9% across deprivation quintiles, corresponding to an OR of 3.16 (95% CI: 1.42-7.00). Of 81 infant deaths, 85% were diagnosed antenatally, with similar detection rates across quintiles. Rates of first- and second-trimester ultrasound among infant deaths did not differ by deprivation. For all live births with CA, detection was 56% overall and did not vary significantly across quintiles (p=0.559). First-trimester ultrasound coverage was high (90.5%) but decreased slightly with deprivation (93.2% in Q1 vs. 87.7% in Q5). Second-trimester ultrasound use remained consistently high across quintiles.

Conclusion(s): Area-based socioeconomic deprivation was linked to higher risks of births with CA, with a threefold increase in infant death risk between the least and most deprived neighborhoods. These findings highlight the role of CA in social inequalities in infant mortality. Antenatal detection and ultrasound rates were similar across quintiles suggesting that inequalities do not arise from differential access to prenatal screening. Instead, they may stem from differences in post-detection care or parental decisions on pregnancy termination. The results underscore the need for health service planning to support more surviving children with CA in deprived areas.

Table 1. Live births and infant deaths according to area-based social disadvantage among births with congenital anomalies
NOTE: (1) P-FDep: an area-based deprivation score derived from the unemployment rate, mean income and proportions of non-home ownership, single parent households and migrants. (2) reference population is derived from census data on children <2 years residing in Paris

Table 2. Detection of CA among live births and infant deaths by quintiles of the area-based social disadvantage score
*Pearson's Chi-squared test
NOTE: P-FDep: an area-based deprivation score derived from the unemployment rate, mean income and proportions of non-home ownership, single parent households and migrants.