What does the fetus look like at five weeks of pregnancy

At five weeks of pregnancy, the fetus does not have much shape. Even when pregnant women go for prenatal check-ups, they cannot see any changes in the fetus through B-ultrasound because it is still in the early stages of pregnancy. Only as the pregnancy cycle progresses can the shape of the fetus in the abdomen be gradually seen. You can also clearly see the baby's skin and hair, and even the nails.

During the fifth week of pregnancy, after the blastocyst implants in the uterus, it will expand in all directions. A layer of flat cells close to the blastocyst cavity begins to differentiate within the cell cluster at one end, becoming the primitive endoderm of the embryo. The remaining larger cells become columnar cells and form the primitive ectoderm of the embryo. The primitive endoderm and ectoderm are disc-shaped, called the embryonic disc, which is about 2 mm long. After a period of development, by the end of the fourth week, a layer of cells differentiates from the ectoderm between the inner and outer germ layers of the embryonic disc, forming the intraembryonic mesoderm. By now, the three germ layers have been formed, which are the basis for the development of the fetus.

Among the three germ layers, each germ layer differentiates into different tissues. The ectoderm differentiates into the nervous system, lens of the eye, membranous labyrinth of the inner ear, surface layer of the skin, hair and nails, etc.; the mesoderm differentiates into the musculoskeletal, connective tissue, circulatory and urinary systems. The endoderm differentiates into epithelial tissue and related glands of the digestive system, respiratory system, bladder, lower part of the vagina and vestibule, etc. During this period, the basic tissues of the nervous system and circulatory system begin to differentiate. At this time, the small embryo is about 0.6 cm long, the size of an apple seed, and looks very much like a "small seahorse."

During the first two months of pregnancy, the baby in the body cannot be called a fetus, but only an embryo or fetal bud. The embryonic period is the time when various organs of the human body differentiate and develop. Many factors that cause malformations are very active. Most people's congenital malformations occur in the embryonic period. In the 4th to 5th week, the heart and vascular system are most sensitive and most likely to be damaged. Exposure to X-rays and other radiation is prohibited during this stage.

If you haven't done an early pregnancy test yet, you can go to the hospital for a physical examination now to get definite information. Good and consistent prenatal care can help you and your baby stay healthy and safe throughout your pregnancy.