Next month, the Nebraska Supreme Court is scheduled to hear an appeal by Maria Luis, a Guatemalan whose rights to her American-born son and daughter were terminated after she was detained in April 2005 on charges of falsely identifying herself to a police officer. She was later deported.

And in South Carolina, a Circuit Court judge has been working with officials in Guatemala to find a way to send the baby girl of a Guatemalan couple, Martin de Leon Perez and his wife, Lucia, detained on charges of drinking in public, to relatives in their country so the couple does not lose custody before their expected deportation.

Patricia Ravenhorst, a South Carolina lawyer who handles immigration cases, said she had tried “to get our judges not to be intimidated by the notion of crossing an international border.”

“I’ve asked them, ‘What would we do if the child had relatives in New Jersey?’ ” Ms. Ravenhorst said. “We’d coordinate with the State of New Jersey. So why can’t we do the same for a child with relatives in the highlands of Guatemala?”

Dora Schriro, an adviser to Homeland Security Secretary Janet Napolitano, said the agency was looking for ways to deal with family separations as it prepared new immigration enforcement guidelines. In visits to detention centers across the country, Ms. Schriro said, she had heard accounts of parents losing contact or custody of their children.

Child welfare laws differ from state to state. In the Missouri case, Carlos’s adoptive parents were awarded custody last year by Judge Dally after they privately petitioned the court and he terminated Ms. Bail’s rights to Carlos.

Image Maria Luis, who was deported to Guatemala, with photographs of two of her children who remain in the United States. Credit... Daniel Hernandez-Salazar for The New York Times

In February, immigration authorities suspended Ms. Bail’s deportation order so she could file suit to recover custody. Ms. Bail’s lawyer, John de Leon, of Miami, said his client had not been informed about the adoption proceedings in her native Spanish, and had no real legal representation until it was too late.