PHILADELPHIA - For Meghan Wall, a marathon effort to start a family has come down to a sprint at the finish line.

Like thousands of U.S. couples, Wall and her husband are racing to complete an adoption from Guatemala by year's end, when promised reforms are expected to slow or stop the exodus of that country's orphans.

"I don't want to get near that date. It's kind of like Y2K. No one really knows what's going to happen," she said.

The 37-year-old Wall, who teaches dance at Princeton University, and her composer husband Michael, 30, fell in love with the brown-eyed baby boy they met on a visit to Guatemala earlier this year. His birth mother had named him "Eddy." They took that as a sign she wanted him raised in the United States.

Then in August, with the adoption humming along, Guatemala clamped down on the outflow of children amid cries it has become a baby mill for wealthy Americans and that women were giving their babies up out of duress or for money.

The reforms come as Guatemala, like the United States, moves toward a 2008 deadline for complying with an international adoption treaty.

Guatemalan adoptions, long handled by private lawyers who sometimes keep half of the $25,000 to $30,000 fee, will be processed by family courts. But those courts are far from ready to handle the approximately 5,000 foreign adoptions that take place each year.

No one even knows when the new system will be up and running, or whether pending adoptions will be grandfathered in.

A bill floated in the Guatemalan Congress makes the Hague treaty effective Jan. 1 and offers what some adoption agencies call a weak grandfather clause. But even at that, it has yet to be voted on.

That leaves thousands of babies in foster care in limbo , and their adoptive U.S. parents in anguish. The situation mirrors the upheaval that followed Romania's 2004 ban on foreign adoptions, and reforms that are slowing down adoptions from China and Russia.

Guatemala, with more than 4,700 adoptions to the U.S. this year, had become the second largest source country for Americans, between top-ranked China (5,453) and Russia (2,310). But that number is expected to drop sharply next year, leaving prospective parents to look to Ethiopia, Vietnam, Ukraine and other emerging source countries.

"It's a roller coaster," said adoptive parent Ann Roth of Chicago.

An educator at Chicago's Brookfield Zoo, she and her husband David, both 38, mortgaged their house to finance the adoption of two Guatemalan infants after enduring two miscarriages and various tests and treatments over seven years.

"Today, I'm under the impression that if we're not out in two weeks, we're done," she said, meaning parenthood would again elude them. "And that's an atrocity. That's (thousands of) children who are going to be left. They should not be stuck in that situation for the rest of their lives."

U.S. Sen. Norm Coleman visited Guatemala late last month to push for legislation that would allow adoptions under way to be completed. At least 70 of his Minnesota constituents are affected.

"The resounding message I heard was that Guatemalan leaders intend to allow families with adoptions already in process to finish them after Jan. 1," Coleman said. "But the key now is for the Guatemalan Congress to turn these assurances into law."

Roth's children, a boy and girl born days apart in November 2006, are among the 46 babies seized after Guatemalan authorities conducted a dead-of-night raid of a private adoption agency called Casa Quivera in August. Officials have spent the months since verifying the birth mothers' consent, the children's DNA and related paperwork in each case.

Jay Richey, a single father from Atlanta, is among the few Casa Quivera parents who have since brought a child home. To do so, he went to Guatemala City and waited out the election season before a local mayor agreed to release a new birth certificate.

"It was a big political issue (adoption reform), so the guy refused to issue it until after the election," said Richey, a 43-year-old marketing specialist. "It was always, 'Manana.'"

But his case had been approved by Guatemalan officials before the raid, a crucial hurdle that Roth has been waiting for since March. Even though the two birth mothers in her case have renewed their consent in recent months, the adoptions appear stalled, she said.

"It's not that corruption shouldn't be fixed, it should be. But how do you do that?" she asked.

Adoption advocates argue that neither impoverished birth mothers nor the Guatemalan government has the means to care for the nearly 5,000 children in foster care and thousands more on the street or in orphanages.

"There is a nationalistic reaction to international adoption in most countries of origin," said Thomas Atwood, president of the National Council for Adoption in Alexandria, Va. "In one sense, you can identify with that, that a country would like to be able to take care of its children.

"However, in most sending countries, there is such a large orphan population that we believe the children's interests override national pride," he said.

The Walls have been trying to start a family since soon after they married in 2003. They, too, endured costly infertility treatments before turning to adoption.

Last month, they received the promising news that Guatemalan authorities had signed off on their case. Now they just need the U.S. embassy to issue a visa. But that can take eight weeks or more.

They sense several deadlines looming.

The threatened Jan. 1 cutoff. The thrill of having a baby at Christmas. And the hope that, four months after they last saw him in a Guatemala City hotel, Eddy could celebrate his first birthday on Dec. 22 in their warm, art-filled rowhome in Philadelphia's eclectic East Falls neighborhood.

"That's very surreal, to have started the mother-son-parenting relationship, and to just have it be in limbo. It's nothing you're prepared for in seventh-grade sex education," Wall said.

"I thought I was trying to do such a simple thing and become someone's mother, share what I have to offer," she said quietly. "I'm trying to remain optimistic."