MALINALCO, Mexico (AP) — As a cold drizzle washed over this town of narrow cobblestone streets in the forested highlands of central Mexico, mothers waiting outside the colonial-era cultural center wrapped wool blankets around the infants snuggled in their arms. Other parents tightened plastic bags around folders filled with U.S. passports and birth certificates from California, Ohio and Texas.

One by one, the parents filed inside, sat down before a Mexican government worker and told stories of lives that had crossed the U.S.-Mexico border twice. First, they crossed illegally into the United States for work, found jobs, and had children. Then, they were caught and deported, or left on their own as the work dried up with the U.S. economic slump. Now they are back in Mexico with children who are American citizens by virtue of being born on U.S. soil.

Because of the byzantine rules of Mexican and U.S. bureaucracies, tens of thousands of those children without Mexican citizenship now find themselves without access to basic services in Mexico — unable to officially register in school or sign up for health care at public hospitals and clinics that give free check-ups and medicines.

At issue is a Mexican government requirement that any official document from another country be certified inside that country with a seal known as an "apostille," then be translated by a certified, and often expensive, translator in Mexico.

It's a growing problem in Mexico as hundreds of thousands return home because of the sluggish U.S. job market and a record number of deportations. Illegal migration of Mexicans to the U.S. is at its lowest level in decades, with more Mexicans now leaving the United States than entering it each year.

More than 300,000 U.S.-born children have been brought to Mexico since 2005, out of a total of 1.4 million people who moved back from the U.S. during that period, according to the Washington-based Pew Hispanic Center.

The number of U.S.-citizen children living in Mexico with at least one Mexican parent reached 500,000 in 2011, according to one demographic study.

Story continues

Many of the Mexican parents of U.S. children were not aware of Mexico's paperwork requirement before they came back, so now tens of thousands are struggling to get their children's documents to the United States to be certified, and then returned to Mexico to be officially translated.

They get little help from the Mexican government, but a lucky few get aid from groups like the Corner Project, a nonprofit organization for migrant families in Malinalco. It arranged for state government workers to travel to the town recently to meet with families and then send packages of documents to different U.S. offices. Returnees living in small towns without government offices otherwise have to make long journeys to deal with officials.

"The government doesn't care about what happens to the people who are coming back," said Maria del Rosario Leyva, who came back with her two U.S.-born children, a 3-year-old boy and a 5-year-old girl, from Santa Ana, California, last year after their father was deported.

She and other returnees have gone to schools and to education offices seeking to enroll their children. Some were sent to Malinalco's records office, which suggested they hire a lawyer.

Rogelio Hernandez Sanchez is another parent who is back. He lost his job as a construction worker in Oakland, California, last year and decided to bring his family to Mexico in November. He was told that not only was he missing official seals on the birth certificates of his two U.S.-born children, but that the documents were no good because they were issued by a health department rather than a government records office, as is done in Mexico.

"They won't give me my kid's grades. I won't be able to take them to a doctor," Hernandez said.

Responding to questions from The Associated Press, Mexico's health officials said in a statement that they offer a temporary care plan for U.S.-born children, but families must certify the youngsters' documents within 90 days to continue receiving health care. An education department spokesman said each Mexican state, and sometimes individual school administrators, can temporarily waive requirements and let children into school despite the lack of official paperwork.

Many parents don't understand what administrators and clerks tell them. Official procedures are often confusing even for college-educated Mexicans. Misconceptions are widespread: Hernandez said he'd heard from other families that if he didn't get the children's documents stamped, U.S. officials could take the youngsters from him, even in Mexico.

"The mothers have come to us for help after multiple frustrations," said Ellen Calmus, director of the Corner Project. "I've literally had a series of mothers in tears coming to the office."

Her group arranged for two state clerks to help about a dozen families at the recent session in Malinalco, and both Leyva and Hernandez were able to send their children's birth certificates to get the official stamps in California. They were given a special permit to show schools that the paperwork is in progress.

Leyva's husband was among 46,000 people deported from the United States in the first half of 2011 who had U.S.-born children. He worked as a chef at a steakhouse in Santa Ana before he was arrested and pleaded guilty to drunken driving and was deported.

After nearly 17 years in the U.S. and with two small children, Leyva worried she would get caught, too, so she left their rented townhome in California. Her older daughter in her mid-20s stayed, but Leyva brought back her 19-year-old son. Both immigrated illegally as children.

A majority of migrants' American-born children stay in the U.S. with relatives, or are taken into state foster care after their parents are arrested for crimes. Demographers say only about 10 to 15 percent of the U.S.-born youngsters are taken to Mexico.

"These are children who are kind of stateless in both countries," said Hirokazu Yoshikawa, academic dean at the Harvard Graduate School of Education and author of "Immigrants Raising Citizens: Undocumented Parents and Their Young Children."

"Each generation is undocumented in one country," he said.

In Washington, Homeland Security Secretary Janet Napolitano has said that the U.S. government worries about U.S.-born offspring of migrants. "Where are the children? What's going on with the children?" she said in an interview with The Arizona Republic newspaper.

The U.S.-born children who are brought back to Mexico have birth certificates and American passports, so they don't need anything else to prove they have citizen rights if they should go back to the U.S.

Leyva says her U.S.-citizen children will not stay in Mexico beyond childhood.

Her eyes moistened as she told of how they often ask when they will return to the United States.

"When they are old enough, they will leave," she said. "Their future is not here. Their children will have papers; the children of their children will also have papers. The problems will end."

___

Adriana Gomez Licon on Twitter: http://twitter.com/agomezlicon