When Amy Birney had to decide what to do with the two embryos that remained after her fertility treatment, she knew one thing for sure: the U.S. government should not have a say in the matter.

But it was 2007, and then-President George W. Bush had imposed restrictions on federal funding of embryonic stem cell research. As much as she may have wanted to, Birney — a health researcher with 10 years of experience with cancer patients — could not donate her embryos for stem cell research.

Instead, she donated them to her doctor, who promised to hold them until he found a study that needed embryos for research that did not use stem cells. Frozen for years, Birney now hopes her embryos can help someone else.

"I chose research over destruction as a means of potentially helping other people," said Birney, 44, a single mother in Oregon who opposed the Bush ban.

"Donating my embryos to research was my own little silent protest of that ban ... Now that the ban has been lifted, maybe my embies will become a new cell line."

U.S. President Barack Obama lifted restrictions on human stem cell research on Monday, a decision that is opposed by some on ethical and religious grounds because the powerful cells come from days-old human embryos.

While medical researchers hailed Obama's move as a step toward treating or curing a variety of diseases, fertility patients said they were simply glad that they will no longer be limited in their choice of what to do with unused embryos.

Some 300,000 frozen embryos were stored in the United States in 2003, according to the American Society for Reproductive Medicine. That number has risen as high as 500,000 since then, according to some estimates.

The embryos were created during fertility treatments such as in-vitro fertilization, or IVF, in which eggs are taken from a woman and fertilized by sperm to create embryos. Typically, one or more of the best quality embryos are implanted in a woman's womb, while any extras are frozen.

Soul Searching

Julie Robichaux is just one of thousands of former fertility patients trying to decide what to do with her three frozen embryos. She and her husband, proud parents of two boys, think they probably do not want more children.

"We've talked about it a lot and I think our preference is for donating to someone else in need of an embryo or two," said Robichaux, who blogged about her battle against infertility and knows many people still struggling to have children.

Robichaux, 38, said infertility patients know full well how valuable embryos are, since many struggled for years to get that far, and can sympathize with people who believe life begins at fertilization.

"(As an IVF patient) you know what your embryo can become. You know the actual, not just the potential," she said.

But she argues that the patients themselves have to have final say about whether to donate their embryos to another family, to research, or to discard them.

"No one comes to IVF without a great soul searching and examination of our own morals. So for the government to take the choice away from us is extremely upsetting," she said.

A 2008 Duke University Medical Center study of patients who had cryopreserved embryos in storage found about half of them intended to use their embryos for future reproduction.

Of the respondents who did not want another baby, 41 considered research donation a very likely option, 16 percent considered donation to another family a very likely option and 12 percent saw disposal as a very likely option.

Still, even with the lifting of restrictions on stem cell research, fertility patients may find it hard to donate their unused embryos to science, said Barbara Collura, executive director of RESOLVE, a national infertility support group.

"There is a big problem within the industry — patients don't always know the logistics of the next step, whatever their option is. They don't know their rights," Collura said.

"The stem cell industry has to think about communicating to those infertility patients, to facilitate the process, because people don't know how to take the next step and no one is telling them how to do it."