Attempting to aid a difficult childbirth with forceps instead of immediately performing a C-section may not raise the risks to the baby in most cases, a new study suggests.

When a woman has difficulties in the second, or “pushing,” stage of labor, the doctor can use forceps or a vacuum pump to pull the baby through the birth canal. That practice, however, has fallen out of favor in recent years, as cesarean section has become the preferred option - partly because of concerns about the risks of using forceps and vacuums.

Those potential risks include skull fracture or bleeding on the brain in newborns, and tissue damage in mothers.

However, performing a C-section during the second stage of labor also presents risks, like increased odds of hemorrhage and bladder damage in mothers.

Therefore, some have questioned the wisdom of the decline in instrument-assisted delivery, according to the researchers on the new study, led by Dr. James M. Alexander of the University of Texas Southwestern Medical Center at Dallas.

Their study, published in the journal Obstetrics & Gynecology, looked at nearly 3,200 women who underwent an unplanned C-section at one of 13 U.S. hospitals. In 640 of these cases, doctors had first attempted to deliver using forceps, vacuum or both.

Overall, rates of certain fetal and maternal complications were higher when there was a try at instrument-assisted delivery.

Mothers were more likely to develop an infection, bruising or fluid buildup at their incision site - nearly 3 percent versus 1 percent of women who had an immediate C-section. They also had a higher rate of failed local anesthesia, which meant they had to be put under general anesthesia - 8 percent, compared with 4 percent of the C- section-only group.

Some newborn complications were also more common with instrument-assisted attempts. One percent of infants developed brain damage due to oxygen deprivation, compared with 0.1 percent of those delivered by immediate C-section.

They were also more likely to have a low Apgar score - a measure of heart rate, breathing and muscle tone - five minutes after birth; just under 2 percent had a low Apgar score, versus 0.6 percent among the other newborns.

However, the researchers found, all 10 of the cases of brain damage were seen in cases where there was a concerning fetal heart rate during delivery. There was no evidence, Alexander’s team notes, that the complication stemmed from damage to skull from the forceps or vacuum.

And when the researchers excluded cases with concerning fetal heart rate readings, there were no differences in the risks of any complications between the two groups of infants.

Fetal heart rate concerns were more common when doctors first attempted an instrument-assisted delivery: in 18 percent of cases, heart rate concerns prompted the C-section, compared with 14 percent of cases where the C-section was done immediately.

The findings suggest that in the absence of heart rate problems, there is no increase in the risk of newborn complications, the researchers conclude.

Together with past research, the findings suggest that attempting an instrument-assisted delivery in “the properly selected patient” minimizes the risks to mothers without increasing the risks to newborns, they wrote.

SOURCE: Obstetrics & Gynecology, November 2009.