The families pleaded with the prime minister to intercede on their behalf in an open letter released Wednesday, saying previous attempts to resolve the issue through diplomatic channels had failed.
"We just want our kids," said Kelly Fox, whose application to adopt a Russian toddler with her husband was abruptly put on hold in the fall.
Fox, a horticulturalist living in Oakville, Ont., said she can't bear the thought of the little boy they've named Dylan Daniil languishing in an orphanage while their case remains in limbo.
"It's heartbreaking," she said.
The Russian government enacted legislation in July prohibiting the adoption of children by same-sex couples and single people from countries that recognize same-sex marriage.
The country's highest court issued a directive in August that appears to apply the ban to all couples from countries — including Canada — that recognize same-sex marriage, don't have a bilateral adoption agreement with Russia and allow the re-adoption of children without Russian oversight.
Immigration Minister Chris Alexander said Wednesday "the decision in Russia is a great disappointment to us and dozens of families in Canada, same-sex or otherwise."
"Our concern is with the children impacted by this decision," he said in an email.
"The government of Canada has raised concerns with the Russian authorities, and we continue to seek clarification and answers about the impact of this new directive for Canadians seeking to adopt children in Russia."
The adoption issue adds to the controversy over a Russian law banning "gay propaganda," which has drawn heavy criticism in the lead-up to the Winter Olympics in Sochi.
Harper waded into the debate last summer, saying Canadians expect his government to defend human rights.
But it wasn't clear Wednesday whether he planned to respond to the families' plea for help.
For Fox and her husband, the crushing news that they might not get custody of Dylan came just as they held a baby shower in anticipation of his arrival.
The couple had already been approved for adoption by both countries and filled out reams of paperwork when the new law restricting foreign adoptions passed, Fox said.
In fact, they had just arrived in Russia to meet the boy they considered their future son, Fox said, adding they were assured that the legislation wouldn't apply to them.
"We met with him for 10 days, we bonded with him...we fell in love with him," she said.
It wasn't until they returned home that they learned of the court's directive, she said.
The couple was nonetheless given a court date in Russia to obtain custody, but their case was put on hold while the judge sought clarification on how to apply the law, she said.
The court has yet to schedule another hearing.
"It's been a roller-coaster," Fox said. "We're not really sure where we go from here...it's a tough situation for us."
Two other couples — Sherry and Derek Wilson of Oakville, Ont., and Kelly Duffin and Jeremy Strain of Toronto — have also signed the letter.