Can developmental dysplasia of the hip be identified in the prenatal period? A pilot study: Ultrasonographic evaluation and postnatal follow-up results of fetal hips in the third trimester

OBJECTIVE: This study aimed to determine the predictability of developmental dysplasia of the hip (DDH) in the prenatal period by means of evaluating fetal hips using the Graf method on obstetric ultrasonography (US) after the 34th week of gestation. METHODS: A total of 84 pregnant women (mean age = 27.04; age range = 19–46 years), who were referred to our radiology clinic for an obstetric US examination in the third trimester, and their fetuses were included in this study. In the obstetric US, alpha angles of both hips of the fetuses were measured based on Graf’s method, and each case was assessed ultrasonographically by a second physician at 6–10 postnatal weeks. Prenatal and postnatal hips were then classified according to alpha angles as ≥ 60° or < 60°. The kappa coefficients between the diagnoses based on prenatal and postnatal alpha angles were calculated. RESULTS: According to the postnatal alpha angle, 77 fetuses were diagnosed to have type 1 right hip and 7 fetuses had type 2A right hip. The prenatal alpha angle provided the same results (77 type 1 and 7 type 2A right hips). Similarly, the postnatal alpha angle revealed type 1 left hip in 82 fetuses and type 2A left hip in 2 fetuses, which was the same as the diagnoses based on the prenatal alpha angles. There was a complete agreement between prenatal and postnatal alpha measurements for both the left and right hips (kappa = 1.00, P < 0.001). CONCLUSION: Evidence from this study has revealed that DDH can be identified by obstetric ultrasonographic examinations in the prenatal period. LEVEL OF EVIDENCE: Level II, Diagnostic Study