Birth during off-hours: an evaluation of obstetric interventions depending on time of birth, attending staff's level of education and unit volume

Introduction:

In the literature concerns have been reported regarding the adequacy of medical care provided by maternity units during off-hours. Risk factors possibly influencing the rate of obstetric interventions during nighttime were discussed previously.

To examine whether time of birth, maternity unit volume and educational level of the attending medical staff during delivery have an impact on the rate of obstetric interventions during birth (emergency CS, secondary CS, assisted-vaginal delivery, episiotomy, fetal scalp blood sampling).

Methods:

This population-based observational study included data on all deliveries at ≥34+0 weeks of gestation between 2004 – 2015 from 10 public obstetric departments in the Austrian province of Styria.

Generalized-Linear-Mixed-Models were used to calculate maternal outcome variables according to time of birth, unit volume and educational level of attending staff.

Results:

The odds ratio for emergency cesarean sections during nighttime compared to daytime was 0.61 (95%CI:0.50 – 0.74). Secondary cesareans in general were less common during off-hours (OR 0.89; 95%CI:0.80 – 0.99). None of the primary variables impacted the incidence of assisted-vaginal deliveries. Compared to deliveries where residents were present, episiotomies were performed more frequently by consultants (OR:1.34;95%CI:1.27 – 1.40) and less frequent by midwives (OR:0.21;95%CI:0.17 – 0.27). Fewer episiotomies were performed during off-hours (OR:0.89;95%CI:0.85 – 0.94) and in units with < 500 deliveries (OR:0.34;95%CI:0.21 – 0.56). Fetal scalp blood sampling was done less frequently in deliveries with interns/GPs attending (OR:0.25;95%CI:0.20 – 0.31) and more often during nighttime (OR:1.15;95%CI:1.06 – 1.25).

Conclusion:

We found that women who deliver during off-hours were less likely to have an obstetric intervention compared to women who deliver during standard office hours, but these results need to be interpreted carefully in lights of worse neonatal outcomes (data published previously, Reif et al., BJOG 2017). The higher rate of cesarean sections during office hours might result from the effort to terminated deliveries with possible complications before staff size is reduced.