The number of women who die from complications of anesthesia during childbirth has plummeted 59 percent over the last two decades thanks to improved monitoring and better medical techniques, according to a recent study.

The report's lead researcher, Joy Hawkins, MD, professor of and director of Obstetric Anesthesia at the University of Colorado School of Medicine, said the risks have been dramatically reduced due to a greater focus on eliminating complications of general anesthesia.

Hawkins examined 12 years of anesthesia-related maternal deaths from 1991 to 2002 and compared them to similar data from 1979 to 1990. She found there were three deaths per million live births from 1979 to 1990, compared to about one death per million live births from 1991 to 2002.

The study, published in the January 2011 issue of Obstetrics & Gynecology, pointed out that while the numbers of women dying under general anesthesia has decreased, those dying under regional anesthetic – spinals and epidurals – have risen slightly to about 3.8 out of every million receiving the anesthesia.

"We focused our attention on the riskier technique – general anesthesia – and we brought those risks down," Hawkins said. "But we should not be complacent about our success. Having said that, one maternal death per million is an incredible safety record."

Historically, women have had a higher chance of dying under general anesthesia during . Many of those deaths occurred while undergoing cesarean sections.

During the 1970s and 80s, 17 women died under general anesthesia for every one death under regional anesthesia. By the 1990s, that ratio dropped to six to one.

"General anesthesia now seems just as safe as a spinal or epidural for cesarean section," Hawkins said.

According to the study, the decline in deaths under is due to, among other things, better monitoring, new methods of dealing with difficult airways and more advanced breathing devices.

The uptick in deaths caused by regional anesthesia is still not fully understood.

"More awareness is being focused on maintaining safety by paying attention to technique and assuring availability of emergency equipment," Hawkins said.

Still, she noted, the risk of death under general or regional anesthesia is remarkably low.

"Obstetric anesthesiologists have focused their efforts and attention on areas of concern, accomplished notable improvements in outcomes and will continue to do so," she said.

Provided by University of Colorado Denver