The main challenge for maternity nurses overseas is that they don't have the same food ingredients as those in China.

"In China, we traditionally stew soup with crucian carp for new moms, as it ensure the women have enough breast milk for the baby. But such fish is nowhere to be found in Western countries," said Hua Hongmei, a 48-year-old maternity nurse from rural Huai'an, Jiangsu province.

"I encourage my overseas clients to ensure they have some traditional Chinese medicine ingredients available for after they give birth," said Hua, who has been to Australia and the United States to care for mothers and their newborns.

Visa problem

Domestic services agencies said they usually suggest their staff obtain tourist visas for jobs overseas as their work contracts are short term.

"Although some of our ayi are from the Hong Kong Special Administrative Region and the island of Taiwan, and it is easier for them to get a visa to the United States," said Iris Yang, a customer services manager at Shanghai Xinmu International Domestic Service.

Once they obtain a visa, some maternity nurses try to make the best use of it by working sequential contracts for different families in different US cities or working in local postpartum care centers until their visa expires.

However, some companies said they don't covet the overseas demand for maternity nurses because it can be hard for their staff to get a visa. One of these is Domo, an agency for domestic workers based in Shanghai.

"It's usually easier for an ayi, who is a local Shanghainese, to get a visa but she usually asks for a higher pay and it's hard for the ayi and the client to reach an agreement," said a supervisor at Domo who only gave her surname as Luo.