Development of the fetus during pregnancy

The embryo begins to develop from three germ layers, which are the material for the formation of the rudiments of all organs and tissues. It develops in a completely closed shell, consisting of two films. All together: both the membranes and the embryo inside are called the fetal egg. Five to six days after conception, implantation occurs – the attachment of the fetal egg to the swollen mucous membrane of the uterus, and this moment is considered to be the beginning of a pregnancy that lasts 40 weeks and ends with the birth of a child. Very important for the expectant mother 2 weeks of pregnancy. Directly on it one of the most important questions is solved: “to be or not to be” a child, t.To. pregnancy occurs on the 13th – 14th day of the menstrual cycle. An embryo develops inside the fetal egg, it is filled with amniotic fluid, they are also called amniotic fluid, and the fetal membranes are called amnion. The outer layer of the ovum forms the placenta, or “baby place”. Translated from Latin, the placenta means “flat cake”, it looks like a flat rounded disk of a tubular structure. This organ belongs to both the woman and the fetus at the same time. One side of it is attached to the uterus, and the other side is connected to the fetus through the umbilical cord. It depends on the placenta how much the developing embryo will be provided with oxygen. Through it, oxygen, according to the laws of simple diffusion, from the mother’s blood enters the child, and in the opposite direction, carbon dioxide is removed. Through the placenta, the fetus receives all the nutrients, and also releases waste products. Harmful substances that accidentally enter the body of a woman are also mostly retained by the placenta. In addition, it serves as an immune barrier, preventing immune conflict between genetically heterogeneous organisms of mother and child. It also synthesizes hormones such as estrogen, gonadotropin, lactogen, progesterone, called the “guardian of pregnancy”. Essentially, this organ functions as the digestive organs, lungs, skin, and kidneys of the fetus. Completely the placenta is formed at 15-16 weeks of pregnancy and reaches 500g. weight and thickness of 2-3 cm. The fetal membranes secrete a transparent, slightly yellowish liquid, amniotic fluid, which maintains a constant temperature in the fetal egg, allowing the fetus to move, protecting it from concussions. The maximum volume of amniotic fluid is a little more than one liter. This number is noted 3-4 weeks before delivery, and then decreases slightly. In the last weeks of pregnancy, a stable composition of trace elements is maintained in the fetal waters, for example, potassium 27 mg per 100 ml of liquid, phosphorus – 2.46 mg, calcium – 7.34 mg.