The original version of this story appeared in Quanta Magazine. When you were a child, it seemed like an ingenious plan: Splash hot water on your face and stagger into the kitchen, letting out a moan ...

The placenta keeps the fetus healthy in the womb and, after birth, can be donated to strangers to offer "miraculous" healing power. The Cleveland Clinic describes the vital role of a healthy placenta.

The placenta has long been thought to produce serotonin during pregnancy. But in a new study, Yale researchers shatter the deep-rooted hypothesis — and show that the placenta doesn’t produce serotonin ...