Every day, Dawn Freney looks at her six children with fresh gratitude, amazed to think each of them protected her while growing in her womb.

It's a logical thought. Last spring, the busy West Chester volleyball mom was diagnosed with multiple sclerosis. Her neurologists, who estimated she's had the crippling disorder for at least nine years, marveled at her vigor, considering she'd had no MS treatment.

What she did have, one after another, were babies. And pregnancy is a time when women with MS usually get a reprieve from the intermittent immune-cell attacks that damage the nervous system.

"I definitely do see, thinking back, where symptoms cleared up," said Freney, 38. "I always felt great while I was pregnant."

Although doctors have long recognized this temporary protective effect, it was neurologist Rhonda Voskuhl who focused on a possible reason: estriol, a form of the female hormone estrogen that is sold as a generic drug. Estriol is made by the placenta and normally surges only during pregnancy.

In a quest to get estriol approved as a therapy for women with MS, Voskuhl is leading a $5.6 million clinical trial at 16 medical centers, including the University of Pennsylvania - where Freney recently became a participant.

If this sounds like a poignant success story, it isn't. As Voskuhl has learned the hard way, generic drugs lack the one thing that drives the costly business of drug development - the prospect of hefty profits. Even if the current trial is successful, getting estriol approved will take many more millions of dollars (money the researcher doesn't yet have) and at least another decade.

Voskuhl, director of the MS program at the University of California Los Angeles, initially thought estriol was a can't-lose proposition. After all, MS strikes three times as many women as men - 300,000 in the United States alone. Unlike the seven brand-name MS medications on the market, estriol comes in a capsule rather than injections or intravenous infusions. It has no notable side effects. And as a generic drug, it's inexpensive.

"The science is great, the idea is great," said Voskuhl, a speed-talker with a faint Oklahoma twang. "I had no idea it would be this hard."

After more than a decade working to bring estriol to patients, Voskuhl, 49, tries to keep her frustration in perspective.

"It's really not so bad for me to go from young to old," she said, "but it's pretty bad to see them go from walking to wheelchairs."

A pregnant pause

In 2001, shortly after the birth of her fourth child, Freney started to feel an electric shock every time she bent her chin to her chest.

A neurologist told her it was Lhermitte's sign, a classic symptom of MS. But a brain MRI scan and other tests showed she was fine, or so he said. And the disturbing jolts stopped.

Freney would later obtain the original MRI report and discover that the doctor wrote: "Thoracic lesion. Could be MS."

But first, she spent almost nine years chasing an explanation for mysterious bouts of numbness, migraines, and vision problems. A Penn neurologist finally diagnosed relapsing-remitting MS, the most common form.

During relapses, which occur about once a year, immune cells gnaw on the protective covering of nerves in the brain, spinal cord, and eyes. This produces patches of swollen, injured tissue that can be seen on MRI scans. The attacks are followed by periods of recovery, or remission.

Research shows that half of patients who go without any treatment for as long as Freney have trouble walking.

She remains remarkably unscathed.

"I've never needed a cane," she said. "I exercise. I was the coach of my oldest child's volleyball team. Knock on wood, I don't have tremors."

MS typically goes into remission during the prenatal period. A 1998 study by French researchers who followed 254 women found that relapse rates fell 80 percent in the last three months of pregnancy.