Caesarean Risk Higher When Labour Induced

by Renee Switzer
June 17, 2007

FIRST-time mothers have a higher risk of needing a caesarean if their baby is induced, new Melbourne research shows.Experts are looking closely at the potential link between induction and caesareans as one way of reducing the increasing caesarean rate. In a study of more than 37,700 women, Mary-Ann Davey, an epidemiologist at La Trobe University's Mother and Child Health Research, looked at all uncomplicated first births in Victoria between 2000 and 2005. The mothers were aged 20-to-34 when they were between 37 and 41 weeks' pregnant. Of those, 9.4 per cent had their labour induced - 6.1 per cent of public patients and 14.1 per cent of private patients. "These women had no medical indication recorded for induction of labour," Ms Davey said. "Common reasons given were 'social' or 'post dates' (but less than 41 weeks' gestation)."

She also found that more women who were induced had epidurals then those who weren't induced. Although her findings are still preliminary, Ms Davey said there was "a substantial and significant increase in the number of caesareans" following an induced labour. Earlier randomised trials had not found that induction led to caesareans, Ms Davey said, "but most of those trials are quite old and don't really reflectthe way people are induced today".Department of Human Services figures show that in 2005, 15.9 per cent of low-risk first time mothers in public hospitals were induced, compared to 23.9 per cent in the private sector. Of all the first-time mothers giving birth, 28.5 per cent had a caesarean after being induced compared to 13.3 per cent who had a caesarean birth but were not induced. For private patients the caesarean figure rose to 31.2 per cent for those who were induced compared to 16 per cent for those who were not.But until further evidence such as Ms Davey's is made public, obstetricians say they have to go by the latest randomised trials that say induction does not increase the risk of caesarean. The chairman of the State Government's quality and safety subcommittee of the Maternity Services Advisory Committee, Euan Wallace, says finding a relationship between inductions and caesareans was a complex issue.Recent Department of Human Services figures showed that the proportion of women under 35 who had a low-risk first pregnancy then went on to have a caesarean in a private hospital rose from 23.4 per cent in 2001 to 27.5 in 2005. In public hospitals, the figure was about 19 per cent since 2003, from 17 per cent in 2001."In a trial format one couldn't say induction of labour leads to caesarean section," Professor Wallace said. "That does beg the question 'how come we have this data suggesting there is an association?'. What is underlying that needs to be looked at is - what is the reason women had the induction of labour?"The college's communications manager, Shannon Morris, said women, doctors and midwives needed to be educated about the risks of induction if there was no medical reason to warrant one."Midwives are of the opinion that if you're induced, you're not ready to have a baby yet. You're inducing a baby that's not ready to be born in a body that's not ready to give birth to it."