Authorities said families paid up to $35,000 to live in a San Gabriel house that was part of a maternity tourism operation.
The women came from China, Taiwan and Korea to have their babies born in the United States, according to investigators. Prof. Edward Chang, of the Asian Studies Department at UC Riverside, said wealthy families are willing to pay to gain U.S. citizenship for the children.
"From the mother's perspective, at least, they are trying to do anything they can for their children," said Prof. Chang.
Authorities said the interior of the San Gabriel home was converted into a maternity ward. Walls were torn down and bathrooms were added to accommodate newborns and their mothers.
The building was shut down for building and zoning code violations. The city issued the following statement: "While the existence of these house is not a widespread problem in San Gabriel, where these uses appear, city personnel will investigate and take appropriate action."
A neighbor said he noticed several pregnant women coming and going.
"Evey day, after dinner time, I would see a pregnant woman and her husband or boyfriend going for a stroll," he said.
The property owner was fined $800 and has filed for permits to restore the townhomes.
A similar operation was discovered in the Hancock Park area in 2006.