Objective: The purpose of this study was to investigate the association between socioeconomic status and orofacial clefts (OFC) in Scotland.
Design: Study of prevalence at birth over a 10-year period using an area-based measure of material deprivation.
Setting: Population-based study throughout Scotland.
Participants: Eight hundred thirty-four live births with OFC born between January 1, 1989, and December 31, 1998, ascertained from the nationwide register of the Cleft Service in Scotland, compared with the total 603,825 live births in Scotland in this period.
Results: There was a strong positive relationship whereby the prevalence of OFC at birth increased with increasing deprivation. This trend was statistically significant for cleft lip and/or palate (CL[P]: p =.016) but not for cleft palate (CP; p =.078). For each type of cleft, the relative risk among those resident in the most deprived areas, compared with those resident in the least deprived areas, was 2.33.
Conclusions: The association between OFC and socioeconomic status is consistent with a report for an earlier period in a smaller part of Scotland. Unlike the earlier study, this pattern appears to be stronger for CL(P) than for CP. These observations do not appear to be an artifact of recording. It is possible that they reflect the association between deprivation and risk factors for OFC, most likely tobacco smoking during pregnancy. Because the relationship between OFC and socioeconomic status appears to have been virtually unstudied in other populations, it would be valuable to investigate this relationship elsewhere and determine whether known risk factors account for the relationship.