The function of the placenta

A crucial role of the placenta during pregnancy is essential for the development of the fetus. This special organ, which connects the mother and the growing child, performs numerous functions, and although science has already discovered much about it, mysteries still surround it. The placenta delivers vital nutrients and oxygen to the fetus while removing carbon dioxide and other waste products. In addition, it produces hormones that help maintain the pregnancy. The functioning and health of the placenta fundamentally influence fetal development and the processes surrounding birth.

The formation of the placenta in early pregnancy

In the early stages of pregnancy, the process of placenta formation is incredibly exciting. The fertilized egg begins to divide in the fallopian tube and, upon reaching the uterine cavity, implants itself. Around the embryo, the amniotic sac develops, filling the space with fluid and thus protecting the developing fetus. The placenta connects to the uterine lining during implantation and continues to grow as the pregnancy progresses. In the end, the placenta can reach a diameter of 20-22 centimeters and weigh between 600-900 grams after the fetus is born.

The structure and function of the placenta

The structure of the placenta is extremely complex, and its function encompasses a wide spectrum. The maternal surface of the placenta forms villi that penetrate the uterine lining. These villi provide the connection to the uterine wall and ensure the flow of nutrients and oxygen to the fetus through the blood vessels located in their central part. Maternal blood continuously flows into the space between the villi to supply the developing fetus with oxygen and nutrients.

It is important to note that there is no mixing of blood between the placenta and maternal circulation, and the nutrient and oxygen molecules enter the fetal bloodstream. The umbilical cord, consisting of two arteries and one vein, provides the connection between maternal and fetal circulation. This complex system supplies the fetus with the necessary substances for 280 days, enabling proper development.

The placenta not only transports nutrients but also produces hormones that play a key role in maintaining pregnancy. Human chorionic gonadotropin (HCG), for example, is produced in the early stages of pregnancy, and its presence in maternal urine is a sign of pregnancy. The placenta also produces estrogen and progesterone, which promote the development of the uterine lining and reduce the sensitivity of the uterine muscles to oxytocin during labor. The levels of these hormones are significantly higher during pregnancy than the amounts produced by the ovaries during cycles.

Problems related to the placenta

The position and condition of the placenta are critical during pregnancy. The most optimal situation is for it to implant in a thick muscular area within the uterus, such as the fundus or the walls. Problems can arise if the placenta is located in the less active lower uterine segment, where blood supply may be weaker. In such cases, the placenta may touch the internal cervical os, which can cause bleeding in severe cases or present a delivery obstacle in the case of a central placenta.

Placental abruption is also a rare but serious complication that can occur due to traumatic impact. The abruption can be partial or complete, and if the central part detaches, a hematoma may form. Minor detachment may heal with scarring, while more significant detachment may require immediate intervention.

Aging, degeneration, and calcification of the placenta can also pose serious problems, especially in the later stages of pregnancy when the needs of the fetus significantly increase. Ultrasound examinations allow for monitoring the maturity of the placenta, and poor-performing placentas may result in the fetus’s weight falling below average. In such cases, it may be necessary to terminate the pregnancy prematurely.

After the fetus is born, the placenta detaches with the contraction of the uterine muscles, usually within 5-10 minutes. Doctors carefully examine the maternal surface of the placenta to avoid complications caused by retained villi, such as bleeding or infection. The health of the placenta thus fundamentally influences the success of the pregnancy and the events surrounding birth.