sikiökalvojen

Sikiökalvot, also known as fetal membranes or amniotic membranes, are structures that surround and protect the developing fetus during pregnancy. These membranes are essential for fetal development and include the amnion and the chorion.

The amnion is the innermost membrane, forming a sac filled with amniotic fluid. This fluid cushions the fetus, regulates temperature, allows for fetal movement, and prevents the umbilical cord from being compressed. Fetal urine contributes to the amniotic fluid volume, particularly in later stages of pregnancy.

The chorion is the outermost membrane and is derived from the ectoderm of the early embryo. It contributes to the formation of the placenta, which facilitates the exchange of nutrients, oxygen, and waste products between the mother and the fetus. The chorion also plays a role in hormone production necessary to maintain pregnancy.

Together, the amnion and chorion form the amniotic sac. This sac ruptures, commonly referred to as "water breaking," typically signaling the onset of labor. In some cases, the membranes may remain intact throughout labor, a condition known as a "caul birth."

The health and integrity of the fetal membranes are crucial for a successful pregnancy. Complications such as premature rupture of membranes (PROM) can lead to infection and preterm birth. Issues with placental development, involving the chorion, can impact fetal growth and well-being.