An ‘in‐hours’ birth represents a desired outcome following induction of labour (IOL) in terms of safety, efficiency and satisfaction. Women booked for IOL are often not commenced at their allocated times, and these sometimes complex births happen after‐hours.

To measure the effect of an 11:00 hours commencement time for IOL.

Materials and Methods
A discrete‐event‐simulation patient‐flow model was constructed. Multiple staffing and scheduling combinations were tested, before a brief pilot and subsequent introduction of a second IOL commencement time. A retrospective cohort study was performed using routinely collected data, comparing outcomes in two four‐month time periods, before and after introduction of the new schedule. During Time Period A, women underwent cervical ripening at 19:00 hours and were reviewed the next morning for amniotomy and oxytocin infusion (ARM/oxytocin). During Time Period B, women were either admitted at 11:00 hours for cervical ripening followed by 23:00 hours ARM/oxytocin, or at 19:00 hours for cervical ripening followed by 06:00 hours ARM/oxytocin. The primary outcome measure was the likelihood of an in‐hours birth (defined as 07:00–19:00 hours).

In an analysis of 1689 women undergoing IOL, the new IOL booking schedule was associated with a 14.7% increase in in‐hours birth (68.4% vs 53.7%; P < 0.01), and a corresponding reduction in overnight births. Although the IOL to birth time was unaltered, we observed a decrease in IOL delays and admission‐to‐birth time, and a greater likelihood of vaginal birth within 24 h of admission. Conclusions Introducing a 11:00 hours start‐time for IOL has been associated with a significant increase in in‐hours births.