Incidence and prevalence of congenital anomalies in low- and middle-income countries: A systematic review

Background: In the absence of robust data from low- and middle-income countries (LMICs), most disease burden estimates and related resource allocation choices are based on historic Northern demographics. We hypothesize that significant discrepancies exist between directly reported LMIC data and surrogate high-income country (HIC)disease burden estimates of correctible congenital anomalies. Methods: Nine online databases were searched for studies reporting incidence and prevalence data on surgically correctible congenital anomalies in LMICs between 2006 and 2017. Two independent reviewers screened titles and abstracts, with a third adjudicating discrepancies. Selected studies were reviewed and analyzed. Results: Of 10,128 identified articles, 98 were extracted for full-text review, and 41 were included, representing 21 LMICs and 18 conditions. Study types included community surveys (34%), prospective (22%)and retrospective (17%)multi-site data, registries (12%), single-site data (12%), and systematic reviews (5%). Data collection periods were 1 to 10 years. The pooled epidemiologic data varied systematically from existing HIC literature, with the incidence of disease being generally lower in LMICs. Conclusions: Marked discrepancies exist between reported epidemiological data in LMICs and HIC literature, in part owing to varying quality of data collection in LMICs. Robust population-based surveys are needed to accurately estimate the burden of surgically correctable congenital anomalies in LMICs. Level of evidence: Level V, expert opinion without explicit critical appraisal. © 2019 Elsevier Inc.