prevalence of cleft lip and palate among four provinces in west and north-west of iran

background: one of the most common anomalies in newborn infants is cleft lip and/or cleft palate (cl/p). in spite of several studies about the prevalence of this, no investigation evaluated this prevalence in the west and north-west of iran. with due attention to different ethnic groups in this area, the aim of this study is to investigate whether the distribution of cl/p live births varies regionally in this area of iran. materials and methods: a cross-sectional study was conducted using hospital registry records to identify all children born with cl/p. the hospitals with a maternity unit were selected in the capital cities of four provinces in the west and north-west of iran, east azarbaijan, kurdestan, gilan, and markazi. the population under study included all infants born alive from 2008 to 2012. results: during the study period, 107,317 live births were registered in the hospitals with a maternity unit of four cities, and 52 infants (0.485/1000 live births) were born with cl/p. the prevalence in rasht, arak, sanandaj, and tabriz cities was 0.557, 0.352, 0.503, and 0.559/1000 live births, respectively (p < 0.05), and in cleft types (p < 0.05). of the 52 infants who were born with cl/p, 24 (46.15%) were girls and 28 (53.85%) were boys (p >0.05), whereas the prevalence of cl/p based on sex was statistically different among the four provinces (p < 0.05). conclusion: this study shows regional variations in the birth prevalence of clefts and various cleft types. the different eff ects of gender on the birth prevalence of cl/p from city-to-city may be explained environmentally and/or by genetic factors affecting the development of oral clefts.