Birth defect is widely used as a term for congenital anomalies. Children with cleft lip and palate may have serious speech, hearing, nutrition, and mental and social development disorders; therefore, this study was designed to determine the overall prevalence of cleft palate, lip, and cleft palate through systematic review and meta-analysis.

In this study, systematic review and meta-analysis of data from studies on the prevalence of cleft lip and palate in Scopus, Embase, Magiran, Web of Science (WoS), PubMed and Science Direct databases were extracted between January 2000 and June 2020. In order to perform the analysis of qualified studies, the model of random effects was used and the inconsistency of studies with I² index was investigated. Data analysis was performed with Comprehensive Meta-Analysis software (Version 2).

According to the results of the present study on cleft palate, the total number of samples entered in the study in 59 studies were 21,088,517 individuals, the prevalence of cleft palate based on the meta-analysis of the reviewed studies in every 1000 live births was obtained 0.33 (95% CI: 0.28–0.38). In the case of cleft lip, the total number of samples entered in the 57 reviewed studies were 17,907,569 individuals. The prevalence of cleft lip obtained based on the meta-analysis of the reviewed studies was 0.3 in every 1000 live births (95% CI: 0.26–0.34), and in the case of cleft lip and palate, the total number of samples entered in the 55 reviewed studies was 17,894,673. The prevalence of cleft lip and palate based on the meta-analysis of the studies reviewed in each 1000 live births was 0.45 (95% CI: 0.38–0.52).

Due to the high prevalence of oral clefts such as cleft palate, cleft lip, and cleft lip and palate; health system policymakers need to take precautionary measures to reduce the number of patients, as well as diagnostic and therapeutic measures to reduce the effects of this disorder in children.