Epidemiology of cleft lip with or without cleft palate in Thais

Abstract Background Oral clefts, including cleft lip (CL), CL with cleft palate (CL/CP), and cleft palate only (CPO), are among the most common birth defects, and if left untreated can cause significant morbidity. Causes are complex and involve both genetic and environmental factors. Several studies have demonstrated the highest prevalence of oral clefts being in Asian, white, and African populations. However, there have been very few epidemiological studies of oral clefts in Thais. Objectives To describe the epidemiology and factors associated with oral clefts in Thais. Methods This retrospective case-control observational study included individuals from numerous regions in Thailand. We reviewed data regarding 784 patients with an oral cleft collected in questionnaires as part of the Thai nationwide Smart Smile and Speech Project from 2006 to 2014. Data regarding patients with oral clefts were analyzed, and compared with data regarding 187 unaffected controls. Results Of 784 cases, CL/CP accounted for 59.8%, CPO 21.9%, and CL 18.3%. A family history of oral clefts was detected in all 3 types ( P < 0.001). Maternal use of any drugs or herbal medicine not prescribed by physicians during pregnancy in cases of CPO ( P = 0.049) and maternal consumption of alcohol during pregnancy in cases of CL/CP ( P = 0.047) were significantly higher than that by mothers of controls. Conclusions CL/CP is the most common type of oral cleft. A family history of oral clefts, and maternal consumption of alcohol or nonprescribed drugs are positively associated with oral clefts in Thais.