Researchers from the U.S. have dispelled a popular myth byconfirming that inducing labour does not increase a woman's risk for caesarean section delivery.
For the study, the researchers at the University of California, San Francisco and the Stanford University School of Medicine reviewed existing research that examined elective induction of labour, in which women have labour induced by choice rather than for medical reasons.
However, the majority of the research findings were limited to women who were about one week past their due date.
"Elective induction can be done in such a way as to avoid raising c-section rates - it's possible," said Dr. Douglas Owens, MD, an author of the study.
The researchers said that although the rate of elective inductions has more than doubled since 1990, the practice has been poorly studied, and physicians have worried these inductions exposed women to higher risk for caesarean and the medical complications that can follow a surgical delivery.
But Owens said that the confusion arises in part from a flaw in the observational studies that link elective induction to higher caesarean risk.
Observational studies usually compare electively induced labour at a particular gestational age with spontaneous labour at the same time in pregnancy.
"That comparison is misleading because it doesn't reflect the clinical decision that women and their physicians must make," said Owens.
Women and their doctors cannot decide to start spontaneous labour on a particular date- they can induce labour or wait.
The risks of induction must be weighed against the risks of staying pregnant. Near the end of gestation, as the foetus gets bigger, staying pregnant increases a woman's chance of needing a caesarean.
And after the full gestational period of 40 weeks, the placenta may transmit oxygen to the foetus less efficiently, which means that in labour, there may be an increased need to deliver via caesarean to prevent foetal distress.
To ensure that their research evaluated the choices women and physicians must make, the team reviewed randomised controlled trials that assigned women to an elective induction group or an "expectant management of pregnancy" (waiting) group at a particular time in late pregnancy.
These studies indicated that elective induction of labour at or after 41 weeks' gestation lowered caesarean risk by 22 percent compared to waiting.
The researchers also observed that women whose labour was electively induced were half as likely to have meconium-stained amniotic fluid-a sign of foetal intrauterine stress.
Both findings suggest elective inductions may be safer than continuing pregnancy past 41 weeks.
However, the researchers noted that obstetricians should be patient enough to see if the induction is working before deciding to try a caesarean.
Thus, Owens advised pregnant women that induction can be done without increasing caesarean risk if obstetricians are willing to give induction of labour sufficient time to work.
"Women should talk with their physician about how they would handle induction and what their approach to the procedure would be," he said.
The findings of the study have appeared in the latest edition of "Annals of Internal Medicine".