Neighbours were suspicious of the daytime silence at the maternity clinic that came to life only after nightfall, though never suspected its disquieting secret - it was breeding babies for sale.
But recent police raids have revealed an alleged network of such clinics, dubbed baby "farms" or "factories" in the local press, forcing a new look at the scope of people trafficking in Nigeria.
At the hospital in Enugu, a large city in Nigeria's southeast, 20 teenage girls were rescued in May in a police swoop on what was believed to be one of the largest infant trafficking rings in the west African country.
The two-storey building on a dusty street in Enugu's teeming Uwani district now stands deserted, shutters down.
Neighbours had lon childless is too high," said clinical psychologist Peter Egbigbo.
"Childless people want to pay any amount for a child and doctors become rich over night," he said, adding that those who are ready to adopt a baby would rather hide the fact that it is not their biological child.
Exchanging babies for cash is widespread in the region and in many cases locals do not see anything wrong in so doing.
"Many people don't even know what they are doing is criminal. They just think it's adoption - you walk into a clinic, pay a fee and you have a baby," said Okoronkwo.
Buying or selling of babies is illegal in Nigeria and can carry a 14-year jail term.
It is estimated that globally hundreds of thousands of people are trafficked annually.
UNICEF, the UN Children's Fund, estimates that at least 10 children are sold daily across Nigeria, where human trafficking is ranked the third most common crime after economic fraud and drug trafficking.