Introduction: 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.
Methods: 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.
Results: 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.
Conclusions: 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.
Keywords: Prevalence; congenital abnormalities; epidemiology; temporal trends.
© 2018 Wiley Periodicals, Inc.