Inducing Labor May Reduce C-Sections

July 31, 2007 — -- Doctors may be able to reduce the need for Caesarean section surgery by inducing labor, a new study suggests.

The conclusion contradicts conventional obstetric wisdom, as inducing labor -- artificially causing birth to occur at a specific time -- has commonly been thought to actually increase the chances that a C-section would be necessary.

The research has big implications, as C-sections have been on the rise for years. Today, nearly one in three babies is born through a C-section, which has become the most common surgical procedure.

But while the surgery is necessary for some (and simply convenient for others -- a trend that has also contributed to the rising numbers), it can sometimes lead to problems that include long recovery times, risk of infection and even death for mother and child.

The research, published Monday in the Annals of Family Medicine, studied 1,869 women in a rural New England hospital.

One group of women were treated according to a specific protocol, which induced labor more aggressively (31 percent of the time), while a control group had labor induced only 20 percent of the time.

Following induction, only 5.3 percent of the women in the study group had Caesareans, while 12 percent of the control group had the surgical procedure.

"I am not claiming a causality here," said study author Dr. James Nicholson, assistant professor of family medicine and community health at the University of Pennsylvania Health System.

"I'm saying there's a pretty strong association, and the association is clear enough and supported enough by other studies that it should be considered for a randomized control trial."

Picking the Ideal Time for Birth

The doctor's first step in the protocol, called the Active Management of Risk in Pregnancy at Term (AMOR-IPAT), was to accurately define a due date for each woman. Nicholson said that this is a preventive approach, developed by a rural hospital in the 1990s.

"We use a scoring system, using each woman's constellation of risk factors, which gives weight to each factor," said Nicholson. "You can figure out the optimal time of delivery, which is between 38 and 41 weeks. The lower the risk, the higher the upper limit to that timeframe."

The optimal time of delivery for each woman is limited on the low end by the maturity of the baby's lungs and on the upper end by the size of the baby and the age of the placenta -- if the placenta becomes too old, it could be harmful. Once a woman has reached the upper limit of her date, it becomes dangerous for her to continue to be pregnant.

"So, at that point, if she doesn't go into labor on her own, then you offer induction," said Nicholson. "You can artificially ripen the cervix before the induction starts; there are different medications and means of doing that."

The doctors primarily used prostaglandin E2, or PGE2, which they inserted vaginally to prepare the cervix for labor. The induction may cause the birth to take longer than a cesarean.

Caesareans comprise 1.2 million of the 4 million births per year in the United States, and Nicholson thinks that's too many.

"Having a first C-section is kind of a big deal, and if we can find a way to safely prevent that -- even if it takes half a day, or a day -- in my mind as a family doctor, that's worth it," he said.

Other Doctors Cite Study Flaws

However, some disagree that inducing labor close to the time a woman is at term will reduce the number of C-sections.

"The problem that we're dealing with here is that we have a conscientious group of physicians trying to solve a very real problem, which most people agree is the excess number of C-sections," said Dr. Michael Klein, emeritus professor of family practice and pediatrics at the University of British Columbia, who wrote an editorial in the Annals of Family Medicine challenging the study.

"In their hands, it appears to work. The problem is that information about early induction has been around for a very long time, and in other peoples' hands, it doesn't work," he said.

"What they fail to acknowledge is that they are a group of physicians with a specific philosophy of care that is highly intimate."

Klein said that because the doctors in the study had continually spent a lot of time with their patients -- which is not always the case in rural or urban hospitals -- they have an easier time knowing when to induce labor.

Klein said that in his hospital in British Columbia, women who are not induced have a C-section rate of about 8 percent, while those who are induced end up having Caesareans 44 percent of the time.

"Childbirth is complex, and requires a complex approach to care, but for some reason, they [the study's authors] want to describe their approach as a simple solution."

The problem, he said, is that the placenta can get too old and become dangerous for the baby -- but no one knows exactly when that occurs.

"Placentas are like people; each one is different," Klein said. "If you approach all these people as if they were the same, you will cause more problems than you solve."

Sizing up Caesareans

"I think the message here is that induction is not always a bad thing," said Dr. Bruce Flamm, clinical professor of obstetrics and gynecology at the University of California at Irvine.

"If you try to induce a woman with a favorable cervix -- one that is starting to dilate, starting to thin out, soft -- very often the induction will be successful. But if cervix is not ready, and you try to induce her, there's a very high failure rate," he said. "If you're cautious with whom you choose to induce, you can have a good outcome."

Flamm said he has seen C-section rates skyrocket during his two decades as an OB-GYN.

"The really interesting thing is what the rate will be 10 years from now, and I don't think anyone knows the answer to that. If I had to guess; there's no cap," he said. "There's nothing pushing rates down now. They're only going to get higher."

Study author Nicholson has a slightly different take.

"I don't think there's enough evidence that people should be running with this and insisting on having this method of care yet," he said. "But hopefully, in the future, with careful application of the induction methods and careful estimation of the optimal time of delivery, this will improve birth outcomes and methods of delivery."