When can obstetric risk be predicted?

The aim of the study was to assess the chronology of the appearance of perpartum obstetric risk factors (POR) in order to define the best moment to evaluate the type of management to which women will be oriented. We have secondarily studied the extent to which inappropriate medical interventions play a role in the genesis of some complications in the deliveries of women who are in principle at low risk.

We conducted a prospective cohort study from January 1 to June 30, 2015 at the Croix-Rousse Hospital of Lyon, a level III maternity, and the Valence Hospital Center, a level II maternity, including all women giving birth at 24 to 42 weeks of gestation at hospital. The women were divided into two groups : one with no known perpartum obstetric risk (POR-) and the other with at least one obstetrical perpartum risk factor (POR+), defined at three different stages (at the last pregnancy monitoring consultation, at the onset of labor at the admission in the delivery room, and at the end of labor just before expulsive efforts). We observed medical interventions and foeto-maternal complications in each group. A non-simple delivery was a delivery involving a medical intervention, or a maternal or neonatal complication, or any combination of these. A secondary retrospective analysis of the practices and management was made for women initially considered POR- at the onset of labor but who had a non-simple delivery to assess adherence to current guidelines according to an audit schedule.

Among 1975 women, we identified 32% women as POR- at end of pregnancy, 21% at start of labor and 20% at end of labor. Among the POR- women at start of labor, 16% had a non-simple delivery. 35% of these non-simple deliveries might perhaps have been avoided by closer adherence to current recommendations. Nonetheless 54% of these women still had an unpredictable and inevitable non-simple delivery that in some cases required an extremely rapid intervention.

Determining and predicting pregnant women who will need additional resources in addition to the usual obstetric and neonatal care is difficult. This identification should be made at the admission for delivery and this risk should be reassessed during labor. There are no women at zero risk of intervention. Therefore, delivery in demedicalized units should not take place in isolated or distant free-standing facilities.