What is the term for the decidua that covers the fetus?

The decidua that covers the fetus is referred to as the decidua capsularis. This specific layer of the decidua develops as the embryo implants into the uterine wall and expands to envelop the gestational sac. It plays a critical role in the protective environment surrounding the fetus during gestation.

The decidua capsularis is the part of the uterine lining that is closely associated with the developing embryo and ultimately provides a barrier and a support system as the fetus grows. As the fetus enlarges, this layer stretches and can eventually fuse with the decidua parietalis, which lines the remainder of the uterine cavity.

Other terms mentioned, such as decidua basalis and decidua vera, refer to different aspects of the decidual structure. The decidua basalis forms the maternal portion of the placenta at the implantation site and is essential for nutrient exchange, while decidua vera refers to the remaining decidua that lines the uterine cavity, not in contact with the fetal membranes. Understanding these distinctions helps clarify the specific roles and relationships within the gestational environment.