chorion
/ˈkɔriɑn/
noun
- The outermost membrane that surrounds an embryo in the womb, helping to form the placenta and protect the developing baby.
- During pregnancy, the chorion develops into part of the placenta.
- Doctors can test cells from the chorion to check for genetic disorders in the baby.
- The chorion is one of the first structures to form after an embryo implants in the uterus.