This is an interesting paper that told me a lot about the origins of OTC and greater availability of pregnancy testing: The feminist appropriation of pregnancy testing in 1970s Britain
Women have long relied on bodily signs such as a missed menstrual period or morning sickness to self-diagnose pregnancy.14 By the early twentieth century, some working-class women continued to offer their urine for visual inspection to the ‘water doctor’, but the medical encounter was increasingly mediated by the laboratory, including for pregnancy testing.15 Between the late 1920s and the mid 1960s, laboratory workers injected women’s urine into living animals—first mice and rabbits, then frogs and toads—to ‘diagnose’ pregnancy. If present in sufficiently high concentration in the patient’s urine sample, the ‘pregnancy hormone’ today known as hCG (human chorionic gonadotrophin, the same molecule later detected by home tests) triggered physiological changes in the animals, which reliably constituted a ‘positive’ result. Crucially, pregnancy testing was, in this period, a diagnostic service for medical professionals only; the only way a woman could obtain the result of a laboratory test was from her doctor. A few specialised centres and most hospitals, but not doctors’ surgeries, were equipped for pregnancy testing. G.P.s would post a patient’s urine sample to a lab and it could take a week or more for the result to come back.16
From the late 1940s, pregnancy testing was made freely available on the N.H.S., but only for medical reasons; doctors rejected demand from so-called curiosity cases: healthy married women likely to have an uneventful pregnancy.
www.tandfonline.com/doi/full/10.1080/09612025.2017.1346869
I thought this was a fascinating insight into a topic that I didn't realise I knew so little about and a reflection on woman-centred healthcare.