The placenta, or placenta, connects the bloodstream of the expectant mother to the fetus via the umbilical cord. It is responsible for supplying oxygen, delivering nutrients, and removing carbon dioxide and waste products. Disruptions in the performance of the placenta can cause serious harm to the unborn child.
What is the placenta?
The placenta connects the developing fetus to the uterine wall to provide food intake, waste disposal, and oxygen delivery. These ‘true’ placentas are found primarily in mammals. The placenta functions as a fetomaternal organ with two components: the fetal placenta, which arises from the same blastocyst as the fetus itself; and the maternal placenta, which arises from uterine tissue. The word placenta comes from the Latin word for “cake.” Because the placenta is responsible for the vital exchange of oxygen, problems with the placenta can threaten the health of the fetus. Placental malposition can also lead to serious complications at birth.
Anatomy and structure
The human placenta has an average length of 22 cm and a thickness of 2 to 2.5 cm; it is thickest in the middle and thinnest at the sides. It weighs around 500 grams and has a reddish-blue or crimson color. The placenta is connected to the fetus by the umbilical cord. This is 55 to 60 cm long and contains two umbilical arteries and an umbilical vein. Spanning the placenta is a network of fine blood vessels, which further dissects into a network sheathed in cells. These terminate in a form of villous tree-like structures. On the maternal side, these structures form into small lobules called cotyledons. In humans, the placenta has a disc shape; in other mammals, it may take other shapes.
Function and tasks
The tissue of the placenta allows replenishment with the mother’s blood, through which an exchange of vital substances is ensured. This includes, firstly, the supply of oxygen and the removal of carbon dioxide back into the mother’s blood. The supply of nutrients via the placenta is directly related to the mother’s diet and state of health. Diabetes or obesity can cause the metabolism to be affected accordingly, resulting in overgrowth or lack of growth. Waste disposal also occurs through the placenta. Urea, acids and creatinine of the fetus is carried by diffusion into the maternal blood. Antibodies can also pass through the placenta to the fetus and protect it for disease. This supply continues even for a few weeks after birth, bringing the child through this critical period. The placenta is also responsible for a number of hormones that regulate the formation and supply of glucose and proteins.
Diseases and medical conditions
A number of complications and medical conditions related to the placenta exist. These include placental insufficiency, disruption of maternal blood flow, and malposition. Placental insufficiency refers to a functional weakness of the placenta. It is not able to supply the child sufficiently. It is divided into chronic and acute. Acute placental insufficiency can be triggered, for example, by strong contractions. Chronic placental insufficiency develops over weeks or months and can lead to a constant supply of deficiency for the child and finally to serious illness. This chronic form can be triggered by diabetes, infections, kidney disease, and also alcoholism and drug abuse. A disturbance in maternal blood flow, such as hypertension, can lead to an undersupply of blood to the fetus. If the placenta is in a malposition, problems can arise when it thus blocks the birth canal and normal birth through the vagina becomes impossible. Causes of this malposition may be the advanced age of the expectant mother, many past pregnancies, previous cesarean sections, curettage, erythroblastosis or multiple births. Especially the intensive smoking of the mother is associated with this.
