Cleft Lip with or without palate in seven countries with two income levels: a cross-sectional study

Background: Cleft lip with or without palate (CL/P) rank among the most prevalent congenital anomalies globally. This study aimed to report the phenotypic patterns of CL/P across seven Middle Eastern and Asian countries, reflecting two different economic levels. Methodology: A cross-sectional, multicountry-study was carried out in seven Middle Eastern and Asian countries (high income: Saudi Arabia, Kuwait, Oman, UAE; lower-middle income: Egypt, Pakistan, Jordan) at major government and university cleft care referral centers. Cleft phenotypes were classified using the LASHAL system, and severity was categorized into seven grades, ranging from unilateral incomplete CL (mild) to bilateral complete CLP (severe). Results: There were 836 CL/P patients; out of them, 337(40.3%) were CL, 499(59.7%) were CLP and 160 (19.1%) diagnosed with associated anomalies. A subgroup analysis demonstrated a significant relationship between country economic level and CL/P severity (P < 0.001), with lower-middle-income countries showing higher rates of unilateral-incomplete-CL and high-income countries presenting more bilateral-complete-CLP. Associated anomalies occurred significantly more among unilateral complete CL cases (P = 0.036). Regression analysis found that low-to-moderate income countries significantly decreased the adjusted odds ratio (AOR) of CLP compared to CL phenotypes (AOR: 0.494, P = 0.032), and having mild compared to severe CL/P (AOR = 0.431, P = 0.029). Conclusion: This multicenter study revealed that the socioeconomic level influences both cleft type and severity. Collaborative research focusing on genetic, environmental, and healthcare access factors is recommended to better explain the socioeconomic variations observed and guide targeted prevention and policy strategies.