monochorionic

adjective
mono·​cho·​ri·​on·​ic | \ ˌmän-ō-ˌkōr-ē-ˈän-ik How to pronounce monochorionic (audio) \
variants: also monochorial \ -​ˈkōr-​ē-​əl How to pronounce monochorial (audio) \

Medical Definition of monochorionic

of twins
: sharing or developed with a common chorion