cytotrofoblaster

The cytotrophoblast is an inner layer of cells within the early placenta that plays a crucial role in placental development and fetal nutrition. During early pregnancy, the blastocyst, a structure formed shortly after fertilization, implants into the uterine lining. As it invades the endometrium, it differentiates into two primary cell layers: the cytotrophoblast and the syncytiotrophoblast. The cytotrophoblast consists of undifferentiated, rapidly dividing cells that contribute to the growth and expansion of the placental tissue.

These cells proliferate and migrate outward, eventually fusing with the outer syncytiotrophoblast layer to form a continuous syncytium. This process is essential for establishing the placental barrier, which facilitates the exchange of nutrients, gases, and waste products between the mother and the developing fetus. The cytotrophoblast also gives rise to extraembryonic mesoderm, which further supports placental formation by differentiating into connective tissue and blood vessels.

In some cases, abnormal proliferation of cytotrophoblast cells can lead to pathological conditions, such as molar pregnancies (e.g., complete hydatidiform mole), where excessive trophoblastic growth occurs without normal fetal development. Proper regulation of cytotrophoblast activity is therefore vital for a healthy pregnancy. Research into these cells continues to provide insights into placental physiology, reproductive biology, and potential targets for therapeutic interventions in pregnancy-related disorders.