The best time to give an epidural to a woman who is in active labour is when she asks for it, a new study suggests.

An epidural refers to painkilling drugs that are injected into the spine. It is effective at reducing labour-related pain and is one of the pain-relieving measures that women in labour can usually opt for.

Previous studies have suggested that the timing of an epidural can prolong labour and even increase the risk of needing a caesarean section. Researchers in Singapore decided to look into this further by analysing data relating to early and late epidurals.

They assessed nine studies involving over 15,700 first-time mothers, who were divided into two groups - those who had been given early epidurals (less than four to five centimeters dilated) and late epidurals (more than five centimeters dilated).

The study found that women in the ‘early' group were no more likely to need a caesarean section than women in the ‘late' group.

Furthermore, those in the ‘early' group were no more likely to require an assisted birth involving suction or forceps as those in the ‘late' group, and having an early epidural did not lead to a longer time spent in the second stage of labour - the pushing stage.

However, the researchers noted that while the length of time in the ‘pushing stage' was unaltered, they were unable to reach a conclusion about the amount of time it took to become fully dilated.

The researchers from KK's Women's and Children's Hospital in Singapore believe that the right time to give an epidural ‘is when the woman requests pain relief'.

"If they request an epidural early during their labour, the evidence we have does not provide a compelling reason why this should be refused," they said.

Details of these findings are published in the Cochrane Database of Systematic Reviews 2014.

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