decidua capsularis

noun

decidua cap·​su·​lar·​is -ˌkap-sə-ˈlar-əs 

variants also decidua reflexa

-ri-ˈflek-sə 

: the part of the decidua in the pregnant human female that envelops the embryo

Common wisdom holds that by the fourth month of human pregnancy the decidua capsularis fuses with the decidua vera, thereby obliterating the uterine cavity.

—Carl J. Pauerstein, The Journal of the American Medical Association