Change in Prevalence of Orofacial Clefts in California between 1987 and 2010

To extend the knowledge base about possible prevalence declines of specific orofacial cleft phenotypes, here we examine prevalence in a population base from California over a two-decade period among numerous race/ethnic groups.

This population-based study used vital statistics and birth defects registry data. Its population involved all births (~1.5 million births) in central California counties from 1987 to 2010. Orofacial clefts were defined as cleft lip with or without cleft palate (CLP, n=1766), and cleft palate (CP, n=922) only. The slope of prevalence of each cleft phenotype over the period 1987-2010 was estimated using weighted least squares regression.

Birth prevalence of CLP was 121/100,000 live births, and 63/100,000 live births for CP. The slope for CLP decreased by 1.2 (slope: -1.2; 95% CI: -1.9, -0.5), and for CP by 0.7 (slope: -0.7; 95% CI: -1.7, 0.2) for CP. Stratification by race/ethnicity or infant sex did not demonstrate a statistical difference in slopes.

We observed a decline in the prevalence in CLP in all ethnic groups, however did not observe the same amount of decline in CP, perhaps due to antenatal screening.