Nguyen Thi Ngoc Nhu, 29, who is identified as leader of the ring, and seven others are being investigated for "trading people under 16" and "forging documents."
"The ring operates not just in Binh Duong but several other cities and provinces. Police are verifying 16 other suspects," said Colonel Tran Vanh Chinh, deputy director of Binh Duong's Police Department.
The arrest of Nhu and her accomplices occurred after Binh Duong police busted the trade of newborns at Binh Duong Obstetrics and Gynecology Hospital two months ago.
Investigators said the ring connected mothers who do not want their babies with infertile couples. As brokers, members of the ring would get commission.
In other cases, members of the ring would buy babies at a price of VND20-30 million (US$805-1,200) each and sell them to couples in need at VND40-50 million.
They also took care of providing fake birth certificates for the babies.
Investigators said the ring has successfully carried out 31 transactions and identified suspects in seven cases.
The highest form of punishment for "trading people under 16" is life imprisonment.