To identify infection risk after caesarean section (CS) or vaginal delivery (VD), nosocomial infection surveillance has been conducted since 2009 in three obstetric units of a French University Hospital Group. Such infections lead to an important increase in morbidity, mortality and costs. Monitored maternal infections were: urinary tract infection, surgical site infection, endometritis, bacteraemia, infections associated with intravascular devices and breast infection. Active healthcare-associated infection surveillance was combined with quality of care improvement measures, practices audits and permanent benchmarking, comparatively to the other maternity units.

In 2016, the surveillance was targeted to infections after delivery in three maternity wards of a French University Hospital Group, according to the French MATER network surveillance protocol. All mothers who delivered in these hospital wards were included. The observed period varied from 4 to 12 months, depending on obstetric unit. Patients’ follow-up was carried out for up to 30 days after VD or CS. Data collected were demographic data, maternal and delivery risk factors, antibiotic prophylaxis, infections of mother or child. Four types of infection are specially targeted in the surveillance: urinary tract infection (UTI) after vaginal or caesarean delivery, endometritis after VD and surgical site infection (SSI) after CS. The observed numbers of infections were compared to estimated numbers of infections according to infection rates obtained from the French maternity network. This network publishes infection rates of 62 maternity units since 1999. Concerning endometritis and UTI after VD and SSI and UTI after CS, standardized ratio of nosocomial infection (SRNI) was calculated.

Globally, 4248 patients were included in the surveillance study in 2016: 3341 (78.6%) after VD and 907 (21.3%) after CS. Forty-five nosocomial infections were observed: 25 urinary tract infections (UTI), 14 surgical site infections (SSI) and 6 endometritis. The incidence rate of UTI was 0.7% after vaginal delivery and 0.3% after caesarean; 0.2% for endometritis and 1.5% for SSI. Global rate of nosocomial infections was 1.0%. The infection rate was calculated in comparison with French maternity network data. The standardized ratios of each infection were 2.30 for UTI and 1.65 for endometritis after VD; 0.69 for UTI and 1.32 for SSI after CS. The rate of patients’ follow-up at 30 days or more was 10.4% after VD and 39.4% after CS. Patients’ follow-up 30 days after delivery was superior to the mean network values [11.7% vs.10.4% (P=0.02)]. Several risk factors were more frequent in our University Hospital Group than in the network: urinary tract infection rate during pregnancy [15.8% vs. 5.7% (P<10⁻³)] and at hospital entry [5.7% vs. 1.1% (P<10⁻³)], artificial delivery and uterine review rate [15.3% vs.11.4% (P<10⁻³)]. Very few of caesareans were first caesarean interventions [7.2% vs. 55.5% (P<10⁻³)]. However, antibioprophylaxis was very frequently practiced for CS [92.3% vs. 75.7% (P<10⁻³)].

Standardized incidence ratios of endometritis, SSI and UTI after delivery were superior to ratios of the French maternity network for this surveillance. The significantly higher percentage of nosocomial infections could be explained by the fact that, in our University Hospital Group, 76% of them were detected after the end date of hospital stay, while in the French MATER network some obstetric units have chosen to count only infections that occur during hospitalization. In addition, patient recruitment in our University Hospital was different to most other hospitals in the French maternity network, since it targeted a particularly at risk population. Finally, measures of quality of care improvement need to be constantly reviewed.