Obstetric interventions for low-risk pregnant women in France: do maternity unit characteristics make a difference?

In many countries the closure of small maternity units has raised concerns about how the concentration of low-risk pregnancies in large specialized units might affect the management of childbirth. We aimed to assess the role of maternity unit characteristics on obstetric intervention rates among low-risk women in France.

Data on low-risk deliveries came from the 2010 French National Perinatal Survey of a representative sample of births (n = 9,530). The maternity unit characteristics studied were size, level of care, and private or public status; the interventions included induction of labor; cesarean section; operative vaginal delivery (forceps, spatulas or vacuum); and episiotomy. Multilevel logistic regression analyses were adjusted for maternal confounding factors, gestational age, and infant birthweight.

The rates of induction, cesarean section, operative delivery, and episiotomy in this low-risk population were 23.9 percent, 10.1 percent, 15.2 percent, and 19.6 percent, respectively, and 52.0 percent of deliveries included at least one of them. Unit size was unrelated to any intervention except operative delivery (adjusted odds ratio [aOR] = 1.47 (95% CI, 1.10-1.96) for units with >3,000 deliveries per year vs units with <1,000). The rate of every intervention was higher in private units, and the aOR for any intervention was 1.82 (95% CI, 1.59-2.08). After adjustment for maternal characteristics and facility size and status, significant variations in the use of interventions remained between units, especially for episiotomies. Results for level of care were similar to those for unit size.

The concentration of births in large maternity units in France is not associated with higher rates of interventions for low-risk births. The situation in private units could be explained by differences in the organization of care. Additional research should explore the differences in practices between maternity units with similar characteristics.