Of camels, silkworms, and contraception

Nomadic traders relied on camels for their livelihood, and for breeding more camels for future trading (and frankly, for survival). Given the long gestation period of a camel (13-14 months) and the requisite time that such pregnant “vehicles” were out of commission, pregnancy was something better left to control than to chance. While permanent contraception (e.g. male castration, etc.) was always an option, this process was not compatible with future breeding strategies to replenish the fleet. Perhaps as a consequence of the writing of Hippocrates on cervical and uterine manipulations (∼400 B.C.), perhaps as an experiment (?), perhaps as an accident (!?!), these traveling traders found that placing several stones into the camel uterus was sufficient to block pregnancies. Then, “simply” removing them would restore the potential for pregnancy in the future. On the opposite end of the globe in New Zealand (this kind of news obviously travels fast!), small rocks were also being placed in a woman's uterus, which made her “sterile as stones” (Himes, 1963). While the concept was rational, the experiment was repeatable, and the outcome was predictable and significant… rocks are rocks, and discomfort is discomfort! Enter the next big advancement – the silkworm! No, silkworms do not have uteri, but they do have… guts? Dr. Richard Richter, a German physician, crafted a ring from silkworm guts (the logic of which escapes me) that could be placed into the uterus and serve the same function in creating an inhospitable environment for pregnancy. This device also contained a loop that extended out of the cervix so that the device could be checked or removed (Richer, 1909). The work was published, but had little recognition or impact. It was not until the late 1920 s that Ernest Grafenberg (1928) reconfigured Richter's silkworm-gut ring to provide for better monitoring (although Grafenberg does not reference Richter, and may not have known about this previous “technology”). Grafenberg's advance was to wrap the silk around a silver wire to visualize it using the new-found X-ray imaging, thereby not requiring a line of silk-gut extending through the cervix. (Yikes – X-rays to visualize a small, silver wire so close to the ovaries, without truly understanding the powerful effects of this irradiation? It was the early 20th century….) Grafenberg continued to modify his device over the next few decades, extending the use of his next-generation rings into England, Canada, and Australia. Grafenberg also expanded his care into patients, providing abortion services to large segments of his contemporary population, and into broad-ranging research. For example, the area in women located peri-urethrally, near the ventral surface of the vagina, was named the Grafenberg spot, more colloquially known as the G-spot. It's anatomy, as well as its existence and its “function”, is controversial, but the G-spot in some women is highly sensitive and erogenous. The silver used in Germany during Grafenberg's time was actually a metallic mixture, with up to 28% copper. In the late 1960 s, Jiame Zipper and colleagues (1969) discovered that metallic copper is toxic to sperm. Indeed, maximizing the efficiency of copper released from an intrauterine device reduced the pregnancy rate from 18% to about 1%. More recent research has expanded in response to the molecular bases for this block to pregnancy – and has more than overcome the setbacks in this device, e.g. the Dalkan Shield. Rocks, worm guts, silk, plastics, metals, and more, the intrauterine device (IUD) has clearly evolved. In modern times, the IUD has transitioned from an experiment, as it was presented at a 1962 conference held by the Population Council of New York, to one of the most popular contraceptive devices on the planet today. With an average of 4 people born for every 2 people dying every second, and with over 7 billion people inhabiting a planet capable of supporting less than 10 billion people, the IUD may be as important to our future as rocks have been in our past. Gary M. Wessel Himes, Norman E. (1963) Medical History of Contraception. New York. Gamut Press, Inc. Richter, R. (1909). Deutsch. Med. Wachr. 35:1525. Zipper et al., (1969). Amer. J. Obstet. Gynec. 105:1274. www.case.edu/affil/skuyhistcontraception/online-2012/IUDs.html www.huffingtonpost.com/valerie-tarico/iuds_b_4132402.html www.ncbi.nlm.nih.gov/pmc/articles/PMC1749527/pdf/bullnyacadmed00161-0098.pdf

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