The Thalidomide Disaster: How a Morning Sickness Drug Caused Birth Defects

In the late 1950s, thalidomide was introduced as a new kind of medication. It was sold as a sedative and later promoted to pregnant women as a treatment for morning sickness. At the time, it was marketed as unusually safe. Advertisements emphasized that it was non-addictive and impossible to overdose on.

This mattered in post-war Europe, where trust in modern pharmaceuticals was high, and regulations were still relatively loose. Doctors prescribed it freely. In some countries, it was even sold over the counter. Very little testing had been done on pregnant women. Even less was understood about how drugs could affect fetal development.

How Thalidomide Was Approved and Distributed

Thalidomide was developed by the German pharmaceutical company Chemie Grünenthal and first released in West Germany in 1957. It quickly spread to other countries, including the UK, Australia, Canada, and parts of Asia and Africa.

Approval processes at the time focused mainly on toxicity in adults. Animal testing was limited, and pregnancy-specific testing was not required. The idea that a drug could cross the placenta and cause severe birth defects was not yet widely accepted. By the time thalidomide was being prescribed to pregnant women, no one had systematically studied its effects on fetal development.

The Birth Defects That Followed

Within a few years, doctors began noticing a sharp increase in rare birth defects. Babies were born with phocomelia, a condition in which limbs are severely shortened or missing. Some children had hands or feet attached close to the torso. Others were born without ears, with malformed eyes, or with damage to internal organs such as the heart, kidneys, and digestive system.

The pattern was unusual. These defects were extremely rare before, but now they were appearing in clusters. It took time to connect the dots. Many of the affected pregnancies had one thing in common: thalidomide use during early pregnancy, often between the fourth and eighth week, a critical period for limb development.

How the Link Was Finally Made

The connection between thalidomide and birth defects was identified independently by doctors in different countries. In Germany, pediatrician Widukind Lenz noticed the pattern and began investigating. In Australia, obstetrician William McBride reached similar conclusions after seeing multiple affected infants whose mothers had taken thalidomide.

Their warnings were initially met with resistance. The idea that a widely prescribed drug could cause such damage was difficult to accept, and pharmaceutical companies were slow to respond. By the time thalidomide was withdrawn from the market in the early 1960s, the damage was already done.

Exact numbers are difficult to determine, but estimates suggest that over 10,000 children worldwide were born with thalidomide-related birth defects. Many more pregnancies ended in miscarriage or stillbirth. Survival depended on the severity of the defects and the medical care available. Thousands of affected children died in infancy. Those who survived often required lifelong medical support, prosthetics, and assistance.

Why the United States Was Different

One country largely avoided the disaster: the United States. Thalidomide was never fully approved there, largely due to the actions of Dr. Frances Kelsey, a medical officer at the FDA. She repeatedly refused approval, citing insufficient safety data — especially regarding pregnancy. At the time, her caution was seen as excessive. But in hindsight, it prevented thousands of cases of birth defects.

In the years that followed, families of affected children fought for recognition and compensation. These efforts were slow, uneven, and often deeply frustrating. Some countries reached settlement agreements. Others delayed for decades. Finally, Chemie Grünenthal publicly acknowledged responsibility years later, but to many survivors, this moment was bittersweet.