WASHINGTON — They're a bane of that decade or two before menopause, growths in the uterus called fibroids that cause bleeding, pain or other problems in nearly a third of women — and they're the number one cause of hysterectomies.

The latest attempted alternative: Insert a tiny electrode through a small hole and zap, an experiment to see how well the heat of radiofrequency energy shrinks fibroids.

"Women still feel they need more options, justifiably so," says Dr. Erika Banks of New York's Montefiore Medical Center, which is among six health centers nationwide testing the new RF ablation method.

There's also news for women trying to decide among already-approved alternatives to hysterectomy. A separate major study aims to determine which of two options — a longtime method named uterine artery embolization or a newer one called focused ultrasound — works better for which women.

"Patients are maybe surprised there is no research that has definitive answers at this point on which procedure is best for their predominant symptom," says Dr. Estella Parrott of the National Institutes of Health, which is funding the comparison study at the Mayo Clinic and Duke University.

For something so common, fibroids bring a lot of mystery. No one knows what causes these noncancerous tumors, although the hormone estrogen plays a role in their growth. At least 30 percent of women experience symptoms from fibroids — severe pain, heavy bleeding, bladder or bowel dysfunction, infertility or pregnancy complications — mostly in their late 30s and 40s. Many more harbour them — two-thirds or more of all women by age 50 — without reporting problems. Black women, also for unknown reasons, are at increased risk.

Tiny fibroids usually cause no symptoms, but they can grow to cantaloupe size. Even not-so-big fibroids can cause serious bleeding if they're in the wrong spot in the uterus.

Problems can come on suddenly, as Avrille Davis, 48, of the Bronx, New York discovered. Told she had fibroids since her first pregnancy more than two decades ago, she didn't develop symptoms until three years ago. But over the past year, this busy nurse started experiencing periods that lasted two weeks, so heavy that she sought the extra protection of a diaper-style undergarment. Ruling out hysterectomy, Davis decided to enroll in the radiofrequency study, lured by the promise of straight-to-the-fibroid treatment.

RF ablation, long used to treat certain cancerous tumors, uses low-energy heat to destroy targeted tissue while avoiding damage to nearby areas. For fibroids, Halt Medical Inc.'s device requires three small abdominal incisions: One for a camera, one for an ultrasound probe to more precisely aim inside the uterus, and one for a needle-like device that sticks inside a fibroid and zaps.

Davis turned out to have more than 22 fibroids, and Montefiore's Banks thinks she got most of them.

"There has been a drastic improvement," Davis said, thrilled that her periods, so far, are back to normal modest bleeding.

RF ablation "looks very promising" based on short-term shrinkage, but a key question is how long that lasts, said Dr. Howard Sharp of the University of Utah, a fibroid spokesman for the American College of Obstetricians and Gynecologists.

That experimental treatment aside, women should carefully weigh the pros and cons of multiple options before deciding what's best for them, Sharp advises:

¦ Surgically removing the uterus remains a key fibroid treatment because it's the only way to ensure fibroids don't return. Fibroids account for about 240,000 of the nation's 600,000 annual hysterectomies.

¦ Myomectomy, surgery that removes fibroids while leaving the uterus intact, is the only option yet recommended for women who still want to become pregnant. Depending on the fibroid's size and location, it sometimes can be done minimally invasively rather than through open abdominal surgery. Later pregnancies usually require c-section deliveries.

¦ Far less invasive is uterine artery embolization, or UAE. Doctors inject plastic pellets into certain uterine arteries to cut off the blood supply feeding the fibroids, which gradually shrink. Premature menopause is a risk.

¦ MRI-guided focused ultrasound requires no incision. Patients sit motionless in MRI machines as doctors use those scans to guide high-intensity sound waves to shrink the fibroids. There is debate over the best size of fibroid to treat, and long-term outcomes are still under study.

That's where the NIH-funded comparison of UAE and focused ultrasound comes in.

Another consideration is how much time women likely have before menopause, when fibroids naturally shrink, cautions Utah's Sharp. With UAE and myomectomy, between 20 percent and 30 percent of women get another procedure or hysterectomy about five years later because of fibroid recurrence, he says.