Background Developmental dysplasia of the hip (DDH) is a relatively common disorder whose aetiology remains elusive. The effect of mode of delivery on DDH remains unclear.

Objectives To determine whether vaginal or caesarean delivery is better for singleton breech infants.

Search strategy Studies were identifies by searching MEDLINE, EMBASE, Cochrane Methodology Register and by hand-searching journals and conference abstracts. Date of most recent search was December 2010.

Selection criteria Studies comparing the incidence of DDH between singleton, breech infants delivered vaginally and those who had caesarean delivery were considered eligible. Studies in English were only included.

Data collection and analysis Data extraction was performed independently by two reviewers. Disagreements were resolved through discussion.

Main results We found seven cohort studies with 32 835 patients. Incidence of DDH was reported based on clinical examination alone or clinical examination and radiological findings. Breech infants delivered through caesarean section had a decreased OR for DDH (OR=0.88 (95% CI 0.78 to 0.99)). There was no statistically significant heterogeneity among the included studies.

Conclusions Caesarean section of breech babies appears to decrease the risk of hip pathology and instability compared to spontaneous vaginal delivery. However, the absence of long-term follow-up, the known high spontaneous resolution rate of DDH and the lack of evidence of the effectiveness of intervention on functional outcomes1 make the net benefit of an elective caesarean section for all breech infants unclear. Further research in the form of randomized controlled trials with long-term follow-up is required.