Postpartum infection in relation to maternal characteristics, obstetric interventions and complications

The purpose was to evaluate the association between maternal characteristics, obstetrical interventions/complications and postpartum wound infections (WI), urinary tract infection (UTI) and endometritis. Furthermore, this study aimed to determine the time from delivery to onset of infections after discharge from the hospital. Three large Swedish Medical Health Registers were scrutinized for the period 2005-2012. A total of 582,576 women had 795,072 deliveries. Women with diagnosis codes for WIs, UTIs or endometritis, from delivery to 8 weeks postpartum, were compared to non-infected women. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated. Increasing age and body mass index (BMI) were both associated with increasing prevalence of postpartum infections. WIs were most strongly associated with cesarean section (CS) (OR 17.2; 95%CI 16.1-18.3), 3rd and 4th degree tears (OR 10.7%; 95%CI 9.80-11.9) and episiotomy (OR 10.2; 95%CI 8.94-11.5). Endometritis was associated with anemia (OR 3.16; 95%CI 3.01-3.31) and manual placental removal (OR 2.72; 95%CI 2.51-2.95). UTI was associated with emergency CS (OR 3.46; 95%CI 3.07-3.89) and instrumental delivery (OR 3.70; 95%CI 3.29-4.16). For women discharged from the delivery hospital the peak occurrence of UTI was 6 days postpartum, while for WIs and endometritis it was 7 days postpartum.