Anchored moms

What term better describes the phenomenon from this story in China's People's Daily;

According to surrogacy centers interviewed by CNN, a growing number of Chinese families are hiring American women as surrogate mothers, making the industry a lucrative one.
The entire surrogacy process typically takes about 15 months and requires couples to make a few visits to the U.S. In total, the cost is around $130,000 -- roughly in line with fees charged by other surrogacy providers, though costs can balloon to around $150,000.

Two reasons the Chinese will pony up;

Paying Americans to carry their children allows Chinese to circumvent their home country's restrictive policies on reproduction -- surrogacy is illegal [and abortion forcible].
Another incentive: The child is automatically a U.S. citizen, and can sponsor their parents for a green card when reaching the age of 21.

Although that the children would become automatically ... U.S. citizen[s] is, at the very least, disputed by Constitutional scholars.