Hoping to help save other women from a similar fate, Eads enrolled in one of Nelson's studies. All the participants were given estrogen patches to wear.

Several months into it, she was asked to come in so the researchers could repeat a blood draw. Something about her hormone levels had looked odd.

Nelson himself called her with the news. "I thought something was wrong," she recalls.

"Are you sitting down?" she says Nelson asked her. "You're not going to believe this. I've got some great news." The reason her hormone levels had looked out of whack? She was pregnant.

When she heard the news, "I was in shock, but I didn't want to tell anybody," Eads says. "I didn't really believe him. I thought maybe they made a mistake."

Eads' son, Aidan, a soccer- and math-loving second-grader, celebrated his 8th birthday this month. Maybe it was the estrogen patch, says Eads, a single mother. Definitely, though, "it was an act of God," she says. "I think he's a total miracle."

Aidan's conception, and a few others in women in his studies, spurred Nelson to study further the fertility potential in POI patients. In research posted online last month by the journal Fertility and Sterility, Nelson and his co authors compared the ovaries and hormone levels of 97 primary ovarian insufficiency patients and 47 women with normal periods.

Using ultrasound, the researchers were surprised to find that three-fourths of the POI patients had follicles - the fluid-filled sacs in the ovary that give rise to egg cells - capable of producing ovarian hormones.

This was the problem, though: While the patients' pituitary glands were releasing plenty of follicle-stimulating hormone, or FSH, which causes follicles to grow, the glands also were releasing excessively high levels of luteinizing hormone, or LH.

LH normally surges once a month, signaling a follicle to break open and release an egg.

Those constantly high LH levels in women with POI cause follicles to try to break open and release an egg too soon. "These women are getting the signal to ovulate all the time," before their follicles are mature enough, Nelson says.

The next step: See if estrogen therapy might suppress LH in POI patients and improve their ovulation rate, says Nelson, who's ready to start such a study as soon as he finds a company that will provide the estrogen and a placebo.