Study Ups Options for Difficult Births

July 1, 2004 -- Vacuum extraction appears to be as safe for use in difficult deliveries as those in which forceps are used, according to the largest study ever to compare complication rates from the two procedures.

The findings from the review of more than 11 million births in the U.S. call into question a 1998 U.S. Food and Drug Administration warning about the dangers associated with vacuum deliveries, researchers concluded.

"The relatively low rate of fatal complications observed among vacuum deliveries argues against the warning provided by the FDA," they wrote in the July 3 issue of the British Medical Journal.

5 Deaths in 10,000 Births

Vacuum extraction and forceps are medical devices that are used to assist the birth of a baby through the vagina. These devices are used most often in cases in which there is evidence of fetal distress or the mother is simply too exhausted to push for a vaginal delivery.

In its 1998 warning, the FDA noted a sharp rise in infant deaths related to vacuum-assisted deliveries; they also saw an increase in reported injuries during the early to mid-1990s. At that time, an average of five adverse events was reported annually, compared with an average of one event a year during the preceding decade.

The report stated that "part, but probably not all, of this fivefold increase can be explained by an increase in [vacuum] usage." The use of vacuum extraction in the U.S. almost doubled during the period, from 3.5% of all deliveries to just less than 6%.

"I think the FDA acted responsibly by alerting everyone to the increase in adverse outcomes, but they did not have the data at the time to adequately compare the risk profiles of vacuum and forceps deliveries," ob-gyn Gary Hankins, MD, tells WebMD. "The study confirms that the risk is substantially similar." Hankins is chief of obstetrics and maternal-fetal medicine at the University of Texas Medical Branch at Galveston.

In the newly published study, researcher Kitaw Demissie, MD, PhD, and colleagues compared newborn death and birth injury incidence among 11.6 million deliveries in the U.S. between 1995 and 1998, using data from the CDC.

They found that the risk of infant death during vaginal delivery was similar for both vacuum-assisted and forceps deliveries in both first-time mothers and those who had previously given birth. Roughly five deaths occurred per 10,000 deliveries for each procedure, compared with 3.7 deaths for vaginal deliveries in which neither procedure was used.

Vacuum Underutilized

Although the use of vacuum devices for vaginal deliveries increased in the mid-1990s, Demissie tells WebMD that the procedure is underused in the United States. These days, he says, doctors often perform C-sections when a vaginal birth runs into trouble.

"The fear of being sued has led many obstetricians to abandon both forceps and vacuums," he says. "But these are safe procedures if used properly."

He cautions, however, that better guidelines are needed to outline the safest use of vacuum devices. Infant injuries and deaths occur most often in cases where the procedure is tried too often or pressure is applied for too long.

"Obstetricians also need more instruction on how to use vacuum devices," he says. "The average obstetric resident probably gets very little training in how to perform [vacuum extraction] by the time he or she graduates."