Baby in womb. circa 1489.
Sketching.

This sketch was the first great visual observation and analysis of the human pregnancy and birth stages.

The surge of scientific endeavors and discoveries during the Renaissance fueled great intellectual minds like Leonardo Da Vinci to explore all parts of life and nature. His ideas eventually established basic principles of modern medicine, science, and engineering. Leonardo's womb study is but one of many. He also developed and designed numerous technological devices which exist today (Airplanes, Helicopters). You can see more sketches here.