Police suspect the owner of the house is a broker in a child trafficking ring, police spokesman Geoffrey Ogbonna said on Friday.
"The proprietress fled before our men got to the place," Ogbonna said. "We met her son and his wife. They are in custody."
The 19 mothers-to-be, between the ages of 15 and 23, were rescued at various stages of pregnancy, Ogbonna told the AFP news agency.
Friday's discovery of the so-called baby factory in the capital of Umuahia was only the latest in what has become a human trafficking epidemic in southeast Nigeria.
A series of black market maternity homes, that take a portion of the profit for the sale of each child, were discovered over the past year.
In most cases, these homes provide an escape from the stigma of conceiving a child outside of marriage.
Some of the women told police that they "ran from home to escape the stigma of having unwanted pregnancies they cannot take care of", Ogbonna said.
But other reports suggest some women have been kidnapped and forcibly impregnated by traffickers. Though police think these cases are extremely rare.
Buyers are mostly couples who are unable to have their own children. Male babies fetch more money than female babies.
"Couples looking for children should go through the legal adoption process," Ogbonna said.
It is illegal to buy or sell children in Nigeria. Human trafficking, including the selling of children, is the third most common crime after fraud and drug trafficking, according to the United Nations.
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