Socioeconomic inequalities in risk of congenital anomaly

TLDR

The study aims to examine socioeconomic disparities in congenital anomaly risk, particularly for specific anomaly subgroups, and calls for larger studies to confirm and explore etiological mechanisms. Researchers conducted a multicentre case‑control study using 858 congenital anomaly cases and 1,764 controls from four UK registers (1986‑1993), assigning area‑level Carstairs deprivation scores based on birth postcode to assess socioeconomic status. Higher socioeconomic deprivation was associated with a 40 % greater risk of non‑chromosomal congenital anomalies, especially cardiac, septal, digestive, and multiple malformations, while no deprivation effect was seen for neural tube defects or oral clefts, and chromosomal anomalies showed a lower risk in deprived groups largely due to maternal age differences.

Abstract

<h3>AIMS</h3> To investigate socioeconomic inequalities in the risk of congenital anomalies, focusing on risk of specific anomaly subgroups. <h3>METHODS</h3> A total of 858 cases of congenital anomaly and 1764 non-malformed control births were collected between 1986 and 1993 from four UK congenital malformation registers, for the purposes of a European multicentre case control study on congenital anomaly risk near hazardous waste landfill sites. As a measure of socioeconomic status, cases and controls were given a value for the area level Carstairs deprivation index, by linking the postcode of residence at birth to census enumeration districts (areas of approximately 150 households). <h3>RESULTS</h3> Risk of non-chromosomal anomalies increased with increasing socioeconomic deprivation. The risk in the most deprived quintile of the deprivation index was 40% higher than in the most affluent quintile. Some malformation subgroups also showed increasing risk with increasing deprivation: all cardiac defects, malformations of the cardiac septa, malformations of the digestive system, and multiple malformations. No evidence for socioeconomic variation was found for other non-chromosomal malformation groups, including neural tube defects and oral clefts. A decreasing risk with increasing deprivation found for all chromosomal malformations and Down9s syndrome in unadjusted analyses, occurred mainly as a result of differences in the maternal age distribution between social classes. <h3>CONCLUSION</h3> Our data, although based on limited numbers of cases and geographical coverage, suggest that more deprived populations have a higher risk of congenital anomalies of non-chromosomal origin and some specific anomalies. Larger studies are needed to confirm these findings and to explore their aetiological implications.