A mini-review of risk factors for developmental dysplasia of the hip: insights from multiple comparative cohort studies.

Developmental dysplasia of the hip (DDH) is a common pediatric orthopedic disorder. While several risk factors, such as breech presentation, female sex, family history, swaddling, and oligohydramnios, are clinically recognized, their quantitative strength of association has not been well established through pooled evidence. This meta-analysis aims to evaluate the risk factors for DDH quantitatively. A systematic search of PubMed and Embase was conducted through December 2025 to identify comparative cohort studies reporting on DDH risk factors. Data were pooled using random-effects models to calculate relative risks (RRs) with 95% confidence intervals (CIs). Review Manager Web was utilized for statistical analyses, and a P value less than or equal to 0.05 was considered statistically significant. 22 studies involving 133 108 participants (3151 DDH cases) were included. Meta-analysis demonstrated that breech presentation (RR = 3.35, 95% CI: 2.37-4.75, P < 0.001), family history of DDH (RR = 3.64, 95% CI: 2.34-5.68, P < 0.001), oligohydramnios (RR = 3.59, 95% CI: 1.43-9.03, P = 0.007), and female sex (RR = 3.74, 95% CI: 2.48-5.62, P < 0.001) were significant risk factors associated with a three to four-fold increased risk of DDH. This study provides pooled quantitative evidence confirming that breech presentation, family history, oligohydramnios, and female sex are significant risk factors for DDH. These findings underscore the importance of targeted screening for infants with these key risk factors.