Thalidomide is a drug that was available to pregnant women for morning sickness. It was first marketed in West Germany in 1957 as an over-the-counter drug for easing morning sickness, anxiety, and sleeping trouble. After its initial launch in West Germany, it was marketed extensively in Europe, Australia, and South American countries – and, though never approved in the United States, it was ultimately used in 46 countries.
As a drug, it was treated as casually as aspirin, but it caused serious birth defects. It is estimated that between 10,000 and 20,000 fetuses were detrimentally affected by thalidomide, with about 40% dying at birth or before their first birthday. The babies who survived most notably had limb abnormalities – some without normal long bone growth in their arms and legs. We often associate the image of children without arms, instead having their hands on their shoulders, as the “image” of thalidomide’s effect.
But sometimes thalidomide causes less visible defects: bone malformations that were not noticeable in external appearance, heart problems, eye defects, urinary tract abnormalities, and even brain damage. Morning sickness is most commonly felt in the first 6 weeks of pregnancy, yet fetal development was so detrimentally affected in those early weeks of gestation.
Depending on which day(s) the mother took thalidomide in these first 6 weeks, different abnormalities resulted. Researchers have documented specific malformations based on what day of fetal gestation thalidomide was taken. For example, when taken on:
day 20 – brain damage
day 21 – eyes damage
day 22 – ears and face damage
day 24 – arm bone deformities
up to day 28 – leg bone damage
Surprisingly, thalidomide did not seem to damage the fetus if it was first taken after 42 days gestation — after the first 6 weeks. It was officially banned in 1961, though pharmacies in Canada continued to sell it until 1962. And although the drug was not approved for use in the United States (thanks to the strenuous efforts of Frances Kelsey at the FDA), there were still clinical trials in the US operated by American drug companies in the 1950s and ‘60s that distributed it to about 20,000 Americans.
There is a question about whether thalidomide causes second-generation birth defects. Doctors have answered this with a very definite “No,” – but there is anecdotal evidence from women who did not have visible birth defects after their own mother’s use of thalidomide. Yet, their children were born with arm bone or leg bone abnormalities.
Although thalidomide is no longer given to pregnant women or women of pregnancy age, its use in medicine has had a resurgence. Since 1998 its use has been approved in the treatment of HIV-related mouth and throat ulcers, as well as HIV-related weight loss and body wasting. Thalidomide and its new derivatives of it are also used in the treatment of various cancers (blood and bone marrow cancers, multiple myelomas, and others), as it stops many cancers from making their own blood vessels, thereby inhibiting cancer’s growth and acts as an immunomodulatory agent (strengthening the immune system to fight cancer cells).
The FDA has also approved thalidomide’s use to treat severe dermatological conditions, such as certain complications in leprosy.