Timing of elective pre-labour caesarean section: a decision analysis

Background: Since caesarean sections (CSs) before 39+0 weeks gestation are associated with higher rates of neonatal respiratory morbidity, it is recommended to delay elective CSs until 39+0 weeks. However, this bears the risk of earlier spontaneous labour resulting in unplanned CSs, which has workforce and resource implications, specifically in smaller obstetric units.
Aim: To assess, in a policy of elective CSs from 39+0 weeks onward, the number of unplanned CSs to prevent one neonate with respiratory complications, as compared to early elective CS.
Materials and Methods: We performed a decision analysis comparing early term elective CS at 37+0–6 or 38+0–6 weeks to elective prelabour CS, without strict medical indication, at 39+0–6 weeks, with earlier unplanned CS, in women with uncomplicated singleton pregnancies. We used literature data to calculate the number of unplanned CSs necessary to prevent one neonate with respiratory morbidity.
Results: Planning all elective CSs at 39+0–6 weeks required 10.9 unplanned CSs to prevent one neonate with respiratory morbidity, compared to planning all elective CSs at 38+0–6 weeks. Compared to planning all elective CSs at 37+0–6 weeks we needed to perform 3.3 unplanned CSs to prevent one neonate with respiratory morbidity.
Conclusion: In a policy of planning all elective pre-labour CSs from 39+0 weeks of gestation onward, between three and 11 unplanned CSs have to be performed to prevent one neonate with respiratory morbidity. Therefore, in our opinion, fear of early term labour and workforce disutility is no argument for scheduling elective CSs <39+0 weeks.