From the Centre for Community Child Health
Developmental hip dysplasia is an abnormal development of the hip joint. There are a number of risk factors, but the condition has also been linked to inappropriate swaddling or wrapping in infancy.
It is very common to wrap or swaddle babies to help them settle, but when wrapping or swaddling is done in a way that your baby's legs are held in extension or the hip joint is restricted, it can have a severe effect on your baby's growing hip joint and lead to developmental dysplasia of the hip (DDH).
Once your baby is born, wrapping their legs in a way that holds them in an extended position can affect the normal growth of the hip, which can cause it to become unstable and dislocate.
Safe wrapping involves the legs being wrapped loosely to allow them to bend at the hips with the knees apart. This position will assist proper development of the hip joint.
There is a handy visual guide to safe wrapping on the Raising Children Network.