From frequent ultrasound checks to powerful pain drugs, a pregnant woman can expect to have access to the latest technology when giving birth.

At Banner Health, the tool for nurses and doctors seeking to help women deliver a baby is a peanut-shaped exercise ball.

Banner Health now equips all of its hospital labor and delivery wards with so-called peanut balls.

The idea stemmed from nurses seeking to curb rising Caesarean-section rates at hospitals nationwide. C-sections are more expensive, pose health risks for patients and take longer to recover from.

With health-care economics tightening in Arizona and elsewhere, these nurses learned through experimentation that peanut balls could provide a natural alternative to more invasive birthing techniques such as C-sections or vacuum pumps.

"We are always looking for innovative ways to have the best outcomes for our patients," said Christina Tussey, a clinical-nurse specialist at Banner Good Samaritan Medical Center. "We always ask our nurses to ask if there is a better way."

After receiving anecdotal reports that nurses who used the peanut balls with expectant mothers had positive results, Tussey decided to test the idea.

The ball is used on women who receive epidural injections to alleviate pain during pregnancy. These women cannot use other proven birthing methods such as squatting or using an exercise ball.

The peanut-shaped ball fits comfortably between the patients' legs, opening their pelvis to create a path for the newborn.

Tussey reviewed the concept with the hospital's review board that vets such clinical trials. Then they recruited two groups of patients to test the theory - those who would be given peanut balls during appropriate stages of labor and those without.

The results were compelling. Those who used the ball decreased the first stage of labor by nearly 90 minutes and the second stage by 23 minutes compared with a control group that did not use the ball.

The real payoff came through lower C-section rates. The C-section rate for the group of women who used the ball was 13 percentage points less than for the group that did not use the peanut ball.

Banner Health, Arizona's largest hospital chain, has shipped peanut balls to all of its labor and delivery wards. It's a small investment - the balls imported from Italy cost about $40 each - with the potential for a big payoff for patients who can avoid costly and invasive C-sections.

"We thought it if worked so well for such a small population, why wouldn't we want to do this for all hospitals across the system?" said Barbara LaBranche, Banner Health's clinical-performance director for obstetrics.

About 30,000 babies are born at Banner Health hospitals in Arizona, Colorado and other states, and Banner's C-section rate is on par with the national average of 30 percent.

The Phoenix-based hospital system expects the peanut ball is among the ways the hospital system will seek to lower the C-section rates.