The babies were bought. The agency paid the pregnant woman and then sold the baby to some Hollywood actor/actress for a profit.
Back in the day, Hollywood celebrities didn’t want to go overseas to get their adopted children, they wanted American babies. They also didn’t want to wait in line or complete any paperwork. If at all possible they also wanted a third party or even a fourth party in the middle of the whole process. Adoption agencies tended to talk and studios would have to pay off money to keep the adoption agencies quiet about the biological parents of babies that actors and actresses were adopting.