According to a recent research study, infant swaddling with any restriction of leg movement may harm unstable hips. This is especially true for babies being treated for hip dysplasia. Physicians at A.I. duPont Hospital for Children in Wilmington, Delaware used dynamic ultrasound to examine infant hips while being swaddled using different methods. These methods included (1) tight traditional swaddling with the legs straight and together, (2) hip-healthy swaddling with plenty of room for full hip movement, and (3) commercial sleep sacks with upper body swaddle that might limit hip movement when the sack size was too small or the upper body wrap extended down over the hips.
Ten babies with a normal exam were being screened for hip dysplasia. The ultrasound studies without swaddling showed that fifteen hips were stable but five had some looseness without dislocation. When those babies were placed in traditional swaddling, one of the loose hips became completely dislocated. When these same babies were placed in hip-healthy swaddling using a blanket or commercial sleep sack and swaddle with plenty of rooms for the legs to move, the hips didn’t change position compared to the ultrasound without swaddling.
Another group of patients was evaluated while in Pavlik harnesses because they had hip dysplasia that was being treated. Tight traditional swaddling was not used on this group because of the known problems from tight swaddling. The good news is that hip-healthy swaddling without any pressure on the legs was safe when the blanket methods were used and when the commercial products were fitted so that the hips had full movement. However, two out of twenty-four hips showed worsening of hip position when there was mild restriction of hip movement caused by improper fit, or a body wrap that extended over the hips.
This report adds more information to the scientific literature about swaddling. The “take-home” messages are:
- Traditional swaddling definitely increases the risk of hip dislocation.
- If your baby is being treated for hip dysplasia, then it’s very important to make sure that any swaddling allows full movement of the hips without any pressure bringing the thighs together or the hips flat.