Social Distress creates Markets Not being able to raise a child costs money

Until 30 years ago, unwed single mothers were exceptions, other than as the result of war. Considered loose and immoral, they were social outcasts, literally pilloried, and banned from cities and towns, their livelihoods ruined. That was the case with girls and women of almost every social status, particularly the lower classes. 

“Maids did not represent a social class, as they were but young, single women who went through this phase solely with the intention of getting married as soon as possible and managing their own household. Their pay was extremely low, and for this reason, a promise of marriage that was not kept or premarital pregnancy represented a social catastrophe. Financial ruin was as good as certain, and the chances of wedding soon vanished. Isolation and life below the poverty line was the high price to be paid for a single moment of weakness. Hardly anyone wished to have anything to do with the ‘fallen woman’.” 

Should a man have been willing to marry such a woman after all, he faced his own disadvantages: “The trades strictly prohibited marriage to a ‘loose’ woman, and any violation would result in the guild shuttering the man’s shop.” 

It’s not surprising that girls and unmarried women did whatever they could to keep from falling pregnant. There were few alternatives open to them: contraception wasn’t easily available, and no reliable methods could be obtained into the 1960s. As a result, women were forced to dispose of their unborn or newborn children. 

Not a child!
In all three areas, there were individuals who found ways of making money from their precarious situation. Quack doctors sold various preparations that were ineffective at best, though many of them were even injurious to the health. Midwives and illegal abortionists advertised their services as ‘help for disorders’ and performed abortions at great personal risk. Being caught or betrayed meant the loss of the licence and exclusion from the profession for midwives, a prison sentence or even execution.
And there were also more or less good-hearted foster mothers who took in newborns for a fee, thereby making the visible proof of ‘immorality’ disappear. 
All of them profited from the suffering of women and mothers. Though they charged tidy fees for their work and the risk involved, the servants, barmaids, etc. who suffered had difficulty paying more than small sums. Few abortionists were able to enter the bourgeoisie. Foster mothers could secure a regular of their own income by taking in foster children, and a contract with an orphanage increased the willingness of local food shops to let a family make purchases on credit.
The last option for preserving reputation and honour was infanticide.

Just one example of many
This theme appears quite often in literature, and also court reporting in newspapers. One spectacular example of an illegal abortionist is Elisabeth Wiese, who was executed in Hamburg in 1905. Originally a midwife, she lost her licence to practice for working as an abortionist. Though married to a respectable man, she broke the law and was imprisoned as a result. After being released, Wiese began to search for sources of income and happened upon newspaper adverts for foster homes for illegitimate children. Although authorization from the police was required for this, which she had not, Wiese offered her services. She also lied to the girls, telling them that well-off parents would be found to adopt their children. For a considerable one-time fee, Wiese would arrange the adoption. A few of the mothers regretted their decision and wanted to contact their children, who had disappeared without a trace. Wiese’s neighbours frequently smelled something being burnt and jokingly spoke of witchery. Years of police investigations in Germany and abroad were unsuccessful. Then, Wiese drowned her newborn grandchild before the young mother’s eyes and disposed of the body.
In pre-trial detention, she attempted to bribe potential witnesses and purchase positive testimony, which didn’t help. “She effortlessly denied the charges against her with considerable rhetorical skill and feigned indignation.” For the murder of at least five – and possibly 16 – newborns and toddlers, Wiese was sentenced to death and executed. A film adaptation of her life was produced in 2010.

See also: https://muvs.org/en/topics/termination-of-pregnancy/the-stigma-of-illegitimacy-en/