Past research has indicated that women who have induced labor are more likely to need a cesarean section. But a new study published in the Canadian Medical Association Journal suggests that evidence to support this is “weak” and women who undergo expectant management of labor – close clinical monitoring of the process – may be at increased risk of cesarean.
According to the research team, including Prof. Khalid Khan of Queen Mary University of London in the UK, around 20% of births are induced – a process used to artificially encourage uterine contractions.
There are many reasons why labor induction is administered, including overdue pregnancy, fetal distress, preterm rupture of the membranes, or the mother may have preeclampsia or diabetes.
The investigators say that labor induction has been criticized for increasing the risk of cesarean section – an operation that involves making a cut in the front wall of a woman’s abdomen and womb to deliver the baby.
The process can pose many risks to both mother and baby, including infection, maternal death and postnatal depression. But the research team notes that recent studies have shown there are fewer cesarean deliveries with labor induction than without it.
To investigate further, the researchers analyzed 157 randomized controlled trials throughout April 2012 involving 31,085 births.
The team found that for pregnancies that were induced at full-term or post-term, there was a 12% lower risk of cesarean delivery, compared with pregnancies that were managed expectantly.
The researchers found that this reduced risk persisted for both high- and low-risk pregnancies, and women who were induced had lower risk of fetal death and other complications, compared with those who underwent expectant management.
In addition, the researchers found that women whose labors were induced using Prostaglandin E2 – a drug commonly used in the US and Canada – had a significantly lower risk of cesarean delivery. But use of oxytocin and amniotomy for induced labor was not associated with reduced risk of cesarean.
Commenting on the findings, Prof. Khan says:
“The risk of cesarean delivery following labour induction was significantly lower than the risk associated with expectant management.
This finding supports evidence from systematic reviews but is contrary to prevalent beliefs and information from consumer organizations, guidelines and textbooks.”
The researchers say their findings provide a “robust answer to the disputed question of risk of cesarean delivery associated with induction of labour.”
They note that their study results also have implications for clinical guidelines as well as the clinical practice of obstetrics. “Our findings are important when selecting candidates for labour induction and when advising women on the risks of induction,” they add.
They conclude that mothers, midwives and obstetricians should be “reassured” by evidence that labor induction may not be as risky as previously thought.
This is not the only study quashing past research related to labor induction. Medical News Today recently reported on a committee opinion from the American College of Obstetricians and Gynecologists, which suggested there is insufficient evidence to suggest that labor induction or augmentation causes autism.