Socioeconomic inequalities in risk of congenital anomaly.
OBJECTIVE
To investigate socioeconomic inequalities in the risk of congenital anomalies, focusing on risk of specific anomaly subgroups.


METHODS
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).


RESULTS
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 Down's syndrome in unadjusted analyses, occurred mainly as a result of differences in the maternal age distribution between social classes.


CONCLUSIONS
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.
Vrijheid
M
M
Environmental Epidemiology Unit, Department of Public Health and Policy, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK. mvrijheid@lshtm.ac.uk
Dolk
H
H
Stone
D
D
Abramsky
L
L
Alberman
E
E
Scott
J E
JE
D016022:Case-Control Studies; D002869:Chromosome Aberrations / Q000453:epidemiology / Q000209:etiology; D025063:Chromosome Disorders; D000013:Congenital Abnormalities / Q000453:epidemiology* / Q000209:etiology; D004314:Down Syndrome / Q000453:epidemiology / Q000209:etiology; D006256:Hazardous Waste / Q000009:adverse effects; D006801:Humans; D007231:Infant, Newborn; D008423:Maternal Age; D016017:Odds Ratio; D012042:Registries; D012307:Risk Factors; D012923:Social Class; D006113:United Kingdom / Q000453:epidemiology
D006256:Hazardous Waste