The duration of the second stage of labour.

Fetal outcomes following extended second-stage labour include respiratory acidosis, lower umbilical vein and artery pH, lactacidaemia and early neonatal seizures. Maternal outcomes following extended second-stage labour include postpartum haemorrhage, puerperal fever, backache, musculoskeletal problems, stress incontinence and denervation of the pelvic floor. It is suggested that intervention should be based on the use of judgement and skill rather than strict adherence to timetables.