HOLLYWOOD, Fla. -

When Janet Pino and her husband married seven years ago, they knew they wanted children. For three years, they tried with no luck.

"It didn't happen month after month. I mean, we used ovulation tests, we did everything and anything," she said.

The coupled turned to fertility specialists.

"They ran all the tests and found nothing wrong," said Pino.

Dr. Kenneth Gelman took the testing a step further and looked for a possible cause in her immune system. He found the answer.

Cells in Pinot's body designed to fight diseases were killing her embryos.

"If the immune system goes awry in any way, we feel that that might be playing a role in either what we would call implantation failure or the ability to even have a positive pregnancy test or the ability to carry a pregnancy to term," he said.

Gelman said blocking a woman's T cells can greatly increase the chances of a successful pregnancy.

Ovarian reserve can also affect fertility. Gelman said there's mounting evidence that DHEA, a supplement, can increase the number of eggs a woman produces.

"It also has been found to improve the quality of the eggs so that the eggs a woman produces while taking DHEA appear to be much more normal," he said.

Gelman cautioned that over-the-counter DHEA supplements won't work.

"The DHEA has to be micronized DHEA, meaning that a pharmacist has to compound it and it has to be well absorbed and fresh," he added. "Otherwise, it's not going to be effective."

After undergoing treatment to block her T cells, Pinot became pregnant. The couple's son is due early next year.

Blocking T cells can also weaken a person's immune system, making them more prone to getting sick.