A Multisite Study of Oral Clefts and Associated Abnormalities in Thailand: The Epidemiologic Data

BACKGROUND: This study aimed to obtain epidemiological data of birth incidences of cleft lips and/or cleft palates (CLP) in the Thai population with associated risk factors. METHODS: The data were collected for a period of 12 months between 2003 and 2004 for infants’ deliveries with CLP and associated risk factors in all hospitals of 6 provinces from 4 regions of Thailand. The birth incidence, related factors with cleft birth, and linkage with geographical area were analyzed by the geographic information system. RESULTS: Phitsanulok, Saraburi, and Khon Kaen had higher birth incidences for CLP of 2.01, 1.69, and 1.66 per 1000 live births, respectively, and the overall birth incidence was 1.51 per 1000 live births. There were a total of 112 cleft births (61 males and 51 females) with 43 cleft lips, 18 cleft palates, and 51 cleft lips + cleft palates. The northeast region had infants with different gestational ages at birth and mothers with higher intakes of vitamins and a use of vitamin A supplement or retinoic acid than others. A use of folic acid supplement was low in all 4 regions. CONCLUSIONS: The varied incidence of CLP may reflect the incomplete accuracy of case ascertainment. A number of challenges were addressed. The geographic information system was helpful for more background investigation and planning of cleft care management. Our study enables future studies of etiological factors and future birth registries.