Defining the abnormal second stage of labour
Reference is made in the previous section to the fact that there is no clear consensus on the acceptable duration of the second stage of labour. Traditionally, in the presence of regional anaesthesia, the cut offs are 3 hours and 2 hours in nulliparous women and multiparous women respectively.
These limits are reduced by 1 hour if regional anaesthesia is not used in labour. In a 2014 obstetric care consensus statement, the American College of Obstetricians and Gynaecologists (ACOG) and the Society for Maternal-Fetal Medicine made the following statements (20):1. Nulliparous women can be allowed 3 hours of pushing and multiparous women can be allowed 2 hours of pushing.
2. Longer durations can be allowed on an individual basis if fetal and maternal condition is satisfactory.
3. No absolute maximum length of time for the second stage has been identified.
It is also clear that the practice of delayed pushing, which refers to allowing a period of time after full cervical dilatation during which the woman is not actively encouraged to bear down, will have a bearing on the duration of the second stage. Delayed pushing is shown to increase the likelihood of a spontaneous vaginal delivery (21). Another consideration is that, although a longer second stage may not have harmful fetal or maternal effects, it may not always be possible in practice as maternal exhaustion may set in.