The Development of an Organ Replacement Concept for the Ovary

As in the case of the thyroid, transplantation of the ovaries was preceded by its opposite: their removal. Removing the ovaries from their intra-abdominal location had only become possible through the general expansion of surgery into the body cavity. It was not before the 1870s that surgeons were able to remove ovaries safely even for the treatment of tumors. Subsequently, the removal of the healthy organs became a relatively common, though not undisputed, operation. Indications for the total removal of the ovaries, even if they showed no signs of pathology, consisted of a number of different health problems that were attributed to the action of this organ at the time, including neurological and mental illnesses, various pains, menstrual problems, bleeding caused by uterine fibroids, carcinoma of the breast, and osteomalacia.

Just as radical thyroidectomy performed for therapeutic reasons eventually led to investigation into that organ’s function, so ovariectomy began as a purely therapeutic intervention that eventually led to new insights into the physiology of the organ. Comparatively little was known about reproductive physiology until the end of the 1800s; in the second half of the nineteenth century, however, most specialists agreed that the ovary was somehow involved in the monthly changes occurring in the uterus and in female sexual functions in general. It was commonly believed that the nervous system mediated the functions of this organ, which many doctors and scientists saw “as a crucial node in the neural matrix of femininity.” One of the dominant concepts in the period from 1865 to around 1900 was the neuronal theory of menstruation that the physiologist Eduard Pflüger had proposed. According to Pflüger, the monthly bleeding of the endometrium was caused by a nerve reflex, through which the ovaries, uterus, and nervous system were functionally interconnected. As in his theory on the regulation of blood sugar levels, Pflüger assumed the existence of an interaction between the organ and the nervous system, and theorized that menstruation was regulated by inhibitor and stimulator nerves, which were in turn controlled through a spinal reflex center.