Muscles and joints shift and jostle. The heart’s pounding rhythm speeds up. Blood roars through arteries and veins. Over the course of a pregnancy, every organ in the body changes. Initiated by a range of hormones, these changes begin as soon as a pregnancy begins. Explore what we know— and don’t know— about pregnancy's effects on the body and brain. Lesson by TED-Ed, directed by Roxane Campoy and Charlotte Cambon.