sikiökalvolla

Sikiökalvo is a Finnish term that literally means “fetal membrane” and refers to the amniotic sac that encloses the developing embryo and fetus during pregnancy. The sikiökalvo is composed of two layers: an inner amnion and an outer chorion, which together form a thin, translucent structure surrounded by amniotic fluid. The amnion is the innermost layer that directly contacts the fetus, while the chorion lies just outside the amnion and is in turn a part of the placenta.

During the first trimester the sikiökalvo develops from the embryo’s ectoderm and mesoderm as it settles into the uterine cavity. It expands in size as the fetus grows, reaching a volume of about 500–600 ml by the end of the second trimester. The membrane provides a protective environment, maintaining sterility, regulating temperature, and allowing the free movement of the fetus. It also serves as a barrier against mechanical injury and contributes to the cushioning of the pelvic organs.

Clinically, a ruptured sikiökalvo (commonly known as the water breaking) is a key event signaling onset of labor. Healthcare providers monitor the condition of the sikiökalvo in high‑risk pregnancies because its integrity can affect fetal infection risk, especially if premature rupture occurs. Amniotic fluid analysis can be performed when pathology is suspected, such as in cases of chorioamnionitis or to assess fetal well‑being through biomarkers.

In obstetric research, variations in sikiökalvo biology are studied in relation to preterm birth, placental insufficiency, and congenital anomalies. Treatments to reinforce the membrane in cases of pathological thinning or effacement are under investigation, and advances in biomaterials aim to replicate its mechanical properties for therapeutic applications.