From baby farm to baby broker

Found this quote in the book Pricing the priceless child, by Viviana A. Rotman Zelizer:

The sentimentalization had an unanticipated and paradoxical effect. By creating a demand for babies, it also stimutated a new kind of baby market. While nineteenth-century women had paid baby farmers to accept their unwanted baby, twentieth-century adoptive parents were willing to pay to obtain an infant. "Baby traffickers" thus found an additional line of business - making money not only from the surrender of babies, but doubling their profits by selling them to their new customers. As a result the value of a priceless child became increasingly monetized and commercialized. Ironically, the new market price for babies was set exclusively by their non-economic, sentimental appeal.

i knew commercial adoption started early twentieth century, but didn't realize that in the nineteenth century women paid to get rid of unwanted babies.