Prevalence of Birth Defects in Iran: A Systematic Review and Meta-Analysis

Introduction: Birth defects are a series of disorders that occur during embryonic life. In Iran, no national situation analysis is available to show the rate of congenital disorders. We aimed to estimate the prevalence of structural birth defects in Iran. Methods: We searched for English studies on PubMed, Scopus and Google Scholar from January 1990 to July 2016. The search for Persian articles was performed in Scientific Information Database and Magiran. Two reviewers assessed the identified articles independently. The relevant studies were selected based on predefined criteria. Data were analyzed using the Comprehensive Meta-Analysis software. Random effect method was used for meta-analysis. Results: In total, 42 studies were included. The prevalence of congenital anomalies was as follows: orofacial clefts, 1.4 per 1,000 births (95% confidence interval [CI]: 1.2-1.6); neural tube defects, 3.2 per 1,000 births (95% CI: 2.5-4.3); urogenital anomalies, 3.9 per 1,000 births (95% CI: 1.2-12.9); musculoskeletal malformations, 3.3 per 1,000 births (95% CI: 2.3-4.9); cardiovascular anomalies, 3.3 per 1,000 births (95% CI: 2.2-5.1); Down syndrome, 0.9 per 1,000 births (95% CI: 0.7-1.2); gastrointestinal disorders, 1.4 per 1,000 births (95% CI: 0.9-2.1). Conclusion: Our results show that urogenital disorders are the most prevalent births defects in Iran, followed by musculoskeletal and cardiovascular malformations.