OBJECTIVE  To analyze the drug resistance of pathogens and risk factors for surgical site infection (SSI) after cesarean section, providing a scientific basis for improving SSI prevention and control measures.

METHODS  A total of 27 050 pregnant women who underwent cesarean section at the International Peace Maternity Child Health Hospital, Shanghai Jiao Tong University School of Medicine from 2018 to 2021 were selected as the study subjects, among whom 132 cases developed SSI. The clinical data of pregnant women were analyzed, and logistic regression models were applied to analyze the risk factors for SSI in pregnant women undergoing cesarean section. Pathogens from incision secretions of SSI cases were identified, and the drug resistance of major pathogens to commonly used antibacterial agents was analyzed.

RESULTS  The incidence of SSI after cesarean section was 0.49% (132/27,050). Maternal body mass index ≥30 kg/m² (OR=3.743), intraoperative blood loss ≥300 ml (OR=1.690), grade III amniotic fluid contamination (OR=2.027), fetal distress (OR=1.667), failed trial of labor (OR=2.075), fever during labor/puerperium (OR=6.322), pregnancy complicated with hypertension (OR=2.003), positive GBS during pregnancy (OR=2.201) and pregnancy complicated with reproductive tract infections (non-viral) (OR=9.215) were risk factors for SSI in pregnant women undergoing cesarean section (all P＜0.05). A total of 127 strains of pathogens were isolated from the incision secretions of 132 SSI patients, including 72 strains (56.69%) of gram-positive bacteria, mainly Staphylococcus aureus, 15 strains (11.81%) of gram-negative bacteria, mainly Escherichia coli, 36 strains (28.35%) of anaerobic bacteria and four strains (3.15%) of fungi, among which 14 strains (32.56%, 14/43) were methicillin-resistant S. aureus and three strains of E. coli producing extended-spectrum β-lactamases.

CONCLUSIONS  Special attention should be paid to pregnant women with fever during labor/puerperium and those with reproductive tract infections during pregnancy. Gram-positive bacteria are the predominant pathogens in cesarean section incision infections, and mixed infections with anaerobic bacteria and multiple bacteria are also relatively common, suggesting that the selection of antibacterial agents for prevention or anti-infection should strengthen the combined use of anti-anaerobic agents.