Development of wound infection or separation after cesarean delivery. Prospective evaluation of 2,431 cases.

Wound infections are a common surgical complication, often requiring a prolonged hospital stay and leading to increased costs. Over a one-year period, 2,431 patients were followed after cesarean delivery with prompt evaluation and culture of all suspicious wounds. Seventy subjects (2.8%) developed confirmed wound infection, and 42 (1.7%) developed noninfected open surgical wounds. Seven (0.3%) fascial dehiscences were diagnosed, requiring surgical repair. Forty of 63 (64%) infected wounds had positive bacterial cultures, with Staphylococcus epidermidis (29%), Enterococcus faecalis (17%), Staphylococcus aureus (17%), Escherichia coli (11%) and Proteus mirabilis (10%) the most frequent isolates. Only 7 of 42 (17%) noninfected wounds had positive cultures, with only S aureus, S epidermidis and Corynebacterium species isolated. Ninety-five percent of the noninfected wounds had blood or serous collections present. Rupture of membranes lasting longer than six hours, emergency cesarean delivery and morbid obesity were associated with a statistically increased likelihood of the development of infected wounds. Emergency cesarean delivery and morbid obesity, but not prolonged rupture of membranes, were associated with an increased likelihood of the development of noninfected wounds. Therefore, it appears that at least two mechanisms are responsible for the development of postcesarean open wounds: (1) increased amniotic fluid and wound colonization due to prolonged rupture of membranes, resulting in a wound infection containing one or more bacterial species derived from the cervicovaginal flora, and (2) increased exogenous bacterial contamination and flora consistent with skin species or breaks in sterile technique, often accompanying difficult or emergency surgery.