ABSTRACT
A combination of factors results in an increased risk for DDH (Table 2) (3,21). Girls are at significantly increased risk (three to five times more than boys), possibly due to increased sensitivity to estrogen/relaxin. Those with an affected family member (parent or sibling) are also at increased risk. Increased likelihood of DDH also results from fetal positioning that puts greater stress on the hips. For example, breech presentation, especially with knees extended, is associated with increased risk of DDH (32). Large infants (32), children of first pregnancies, and those complicated by oligohydramnios have increased risk for DDH, presumably because of restricted fetal motion resulting in reduced flexion and abduction at the hip (33). Additional risk factors, torticollis (34) and clubfoot, are probably associated with positioning issues as well. The left hip is four times more likely to be affected than is the right, probably because of fetal positioning, with the left side on the mother’s spine, resulting in limited abduction on that side (33). Premature infants are less likely to be affected (35).
