Objective: To review systematically the evidence on prolonged second stage of labour and the maternal outcomes and neonatal outcomes. Data sources: Medline, Cochrane, Embase and CINAHL found 3580 papers by two-person review using an inclusion and exclusion criteria for both maternal and neonatal outcomes. 1 additional paper was identified by supervisor. Methods: An initial search was conducted on the online databases. Patients who had singleton vaginal births were included, along with studies of women who underwent emergency caesarean sections as complications of labour for differing reasons. A meta-analysis was performed to combine results on two outcomes, namely neonatal intensive care unit (NICU) admission and birth asphyxia. All other outcome results were presented using narrative synthesis. Quality: Quality was assessed using inclusion and exclusion criteria alongside CASP cohort study checklists. Results: This systematic review identified 16 papers to be eligible for inclusion. 13 of the 16 studies reported maternal outcomes. Post-partum haemorrhage, caesarean hysterectomy, chorioamnionitis, 3rd and 4th degree perineal tears, caesarean delivery and episiotomy were associated with prolonged second stage of labour. Post-partum haemorrhage showed between a 2 to 5-fold increase across the studies. Caesarean hysterectomy was linked with between a 6- and 7-fold increase and chorioamnionitis showed a 4 to 5-fold increase when labour was prolonged in the second stage in more than one study. 3rd and 4th degree perineal tears and episiotomy both were associated with an approx. 2-fold increase when second stage labour duration was prolonged. Caesarean delivery showed a 34-fold increase in incidence was second stage of labour became prolonged in one study. Ten studies papers were identified which reported neonatal outcomes. Prolonged second stage of labour was associated with a 1.35-1.85 -fold increase in neonatal intensive care unit admission .Duration greater than 4 hours was associated with a 2.5-fold increase in asphyxia. Conclusion: Prolonged labour second stage of labour is associated with some adverse maternal and neonatal outcomes, specifically: post-partum haemorrhage, caesarean hysterectomy, chorioamnionitis, 3rd and 4th degree perineal tears, caesarean delivery, episiotomy, neonatal intensive care unit admission and birth asphyxia. Reduction and better understanding of these outcomes involves future global standardization of the definition of prolonged second stage. This systematic review provides evidence to inform health professionals’ and pregnant women’s decision-making regarding management of labour when second stage is prolonged.