Prevalence of cleft lip and palate among four provinces in west and north-west of Iran

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. 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. 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). This study shows regional variations in the birth prevalence of clefts and various cleft types. The different effects 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.