Developmental dysplasia of the hip (DDH) is a wide-spectrum disease with a multifactorial etiology and, despite its prevalence, no definitive etiology has yet been established. The aim of this study was to investigate new risk factors for DDH by evaluating newly defined potential risk factors. A total of 71 infants were separated into 2 groups:Group I, 28 female first-born infants diagnosed with DDH and their mothers;and Group II, 43 healthy female first-born infants and their mothers. The maternal height and weight before pregnancy, infant height and weight at birth, and body mass index (BMI) of both mother and infant were determined. Calculations were made of the ratios between these parameters. Of the examined risk factors, only maternal height and the ratio of maternal height to infant BMI (MH/I-BMI) were found to be significant for DDH in infants. In conclusion, the results of this study show that a short maternal height and a low MH/I-BMI increase the risk of DDH. Further studies with a larger series are necessary to confirm these results.