Wholly by chance, it was discovered that the presence of a foreign object in the womb prevents pregnancy. A century ago, a certain Dr Gräfenberg of Berlin produced the first coils by winding silver wire and silk suture. Later models were made of plastic. However, the first frequently caused inflammation, which prevented this method from becoming widely accepted.

The only coil actually shaped like a coil, a model designed by Dr Margulies in 1960, failed to win over a large following. Its name, however, became the term used for all intrauterine devices to the present day.

In the 1960s, Dr. Zipper of Chile discovered that a small piece of copper wire would prevent sperm from fertilizing an egg, which represented a considerable improvement over the coil models available at the time. The copper coil has since become the standard.

But innovations are still being made. Some examples are new shapes that should cause fewer complications, and addition of a small amount of a hormone, gestagen, has produced excellent results (Mirena®).