Fetal station at the time of labour arrest and risk of caesarean delivery.

This study aimed to determine whether an unengaged vertex in nulliparous women experiencing active phase labour-arrest increased the caesarean delivery risk. We selected a retrospective cohort of 393 patients. Of these, the presenting part was unengaged in 307, and engaged in 86. Compared with the engaged vertex, unengaged vertex significantly increased the risk of caesarean delivery (27% vrs 7%, P < 0.001, with the risk increased 5 fold [Odds ratio 4.94, confidence intervals 2.08, 11.76]. The risk remains significant after adjusting for confounding variables on multiple logistic regression [adjusted OR 4.71, CI 1.99, 11.01]. However, the degree of unengagement did not significantly affect caesarean rate. (39% at -3 station, 39% at -2 station, and 33% at -1 station; P = 0.577). While an unengaged vertex significantly increased the caesarean delivery rate, the degree of unengagement did not, and the eventual vaginal delivery rate (73%) is high and should prevent hasty recourse to caesarean delivery.