To give or not give antibiotic prophylaxis for planned caesarean section: An assessment of risk of postpartum prescription of antibiotics depending on prophylaxis regimen

Introduction: No national recommendation for antibiotic prophylaxis for planned caesarean section in Sweden exists. Swedish delivery units have chosen different strategies. Some units routinely administer antibiotic prophylaxis to all women for whom a caesarean section is planned, while other units give prophylactic antibiotics to risk groups only. We took advantage of this "natural experiment" to compare the risk of antibiotic prescription postpartum after planned caesarean section, by antibiotic prophylaxis strategy.

Materials and methods: An observational study based on data from Swedish registers. The population is based on women giving birth by planned caesarean section from 37 + 0 weeks of gestation, 2014-2020 (n = 7308). The risk of antibiotic prescription postpartum was compared between women who delivered in hospitals with a general routine of administrating antibiotics (n = 5637) for planned CS and women who delivered in hospitals administrating prophylaxis in conjunction with planned caesarean section to risk groups only (n = 1671). Adjusted incidence rate ratios (AIRR) were obtained using modified Poisson-regression models, adjusting for maternal age, parity, and body mass index.

Main outcome measures: Antibiotic postpartum was defined as a prescription of antibiotics postpartum 2-42 days after planned caesarean section.

Results: No difference in antibiotic prescription postpartum among women in hospitals with a general routine of prophylaxis, compared to women in hospitals with a risk-based strategy was found, RR: 1.18 (95 % CI 0.99-1.40). Women with identified risk factors (diabetes/gestational diabetes and/or BMI > 30), were more likely 1.52 (95 % CI 1.03-2.25) to receive a prescription postpartum in hospitals with a general routine of antibiotic prophylaxis than women delivered at hospitals with risk-based strategy.

Conclusions: We found no evidence that routinely administrated prophylactic antibiotics for women with planned caesarean section reduced the risk of a prescription of postpartum antibiotics in a setting with high hygiene standards. Instead, the incidence of prophylactic antibiotics was positively associated with postpartum antibiotic prescriptions and speculate that this reflects local practice routines rather than complication rates.