The federal agents who target maternity tourism’ schemes, in which pregnant Chinese women travel to the United States, usually on tourist visas, so that their children will be born as US citizens, on Tuesday, has raided three operations, including You Win USA in California.

These raids have marked the biggest federal investigation of its kind, aiming at cracking down against the extensive practice of foreign nationals traveling to the US only to give birth.

As per the affidavit, the agents raided a company, Star Baby Care, which has boasted on its site that it had served 4,000 women from China since it was founded in 1999.

In order to carry out the investigation, groups of agents went to the apartment complexes in Los Angeles, Orange and San Bernardino counties, carting out the boxes of documents, diaper containers and trash, and they also interviewed pregnant women to the backdrop of wailing babies.

The main motive of the agents was to find the proof of visa fraud, conspiracy and other crimes, wherein women were helped in the fabrication of documents for visa applications and were trained to falsely claim that they were traveling to the US for tourism.

According to an affidavit, one business stated on its website that the US might say no to entry if the belly of the mother is too big, recommending women to travel at 24 to 30 weeks into their pregnancy. The website also mentioned that the size of the belly is very important for the determination of your arrival in Los Angeles.

Such businesses are commonly known as ‘maternity hotels’ or ‘birthing centers’. These have created a big problem for the local government and law enforcement because it is not necessarily illegal for foreign nationals to give birth in the US.

Taiwanese, Korean and Turkish mothers are also a part of this birth tourism, but in the recent years the practice has become quite popular with the newly wealthy Chinese middle class.