Prolonged labour is classed as any labour that takes longer than 18 hours. It is more common in first time mothers or mothers over 35.
There a number or reasons why prolonged labour may occur. One of the most common reasons is tension in the mother, which is known to slow down the progress of contractions.
This often happens when a woman reaches the unfamiliar surroundings of a hospital and starts to feel anxious. When anxiety sets in, the uterus - which is a muscle - tenses up, which halts the progress of the contractions. For this reason, women are advised to stay at home for as long as possible in order to allow the labour to continue without the risk of undue anxiety or stress.
The position of the baby's head is also a reason for prolonged labour. If the baby's head is not tucked into its chest - which is the optimum position - the baby's chin can halt the progression through the birth canal, thus prolonging labour.
The overall position of the baby's body is also a key factor in slowing down labour. If the baby is in a position such as breech (feet first) or back to back (where the baby's back is lying against the mother's spine), this will have an impact as the progression through the birth canal will be hindered by the position.
If labour fails to progress, a woman will be offered an oxytocin drip to encourage contractions and dilation or, in necessary circumstances, a caesarean section.