This study is a double-blinded randomized controlled trial with a concurrent Health Economic Assessment. The study will examine the effect of change in timing of prophylactic antibiotics on the rate of post-CS infections (endometritis, UTI and WI). The study will be performed at the obstetric departments at Odense University Hospital (OUH), Hvidovre Hospital (HH) and Hospital South West Jutland (HSWJ) in collaboration with the Department of Clinical Microbiology, OUH, to ensure that the most appropriate antibiotic regime is used. Furthermore, collaboration with a neonatologist will ensure appropriate assessment of neonatal outcome.