Naturally human body secretes -specifically in the morning- sufficient amounts of pregnancy hormone during pregnancy -this secretion can be noticed in the urine of motherhood- and the hormone are called human chorionic gonadotrophin (HCG). This process happens after blastocyst- it is an embryonic stage when an embryo is settled in the wall of the womb. High HCG play a vital role during pregnancy: it sustains pregnancy and keep your pregnancy test positive. Now this is the time to protect the embryo from infection. Like guardian mucus develop a layer at the gate of womb.
Growth of a fetus in 4th Week Pregnancy
When you are 4 weeks pregnant, the development of fetus will be started from division in the embryo. The embryo is divided into three layers: ectoderm, mesoderm and endoderm. The ectoderm is the outer layer and it yields into baby’s brain, nervous system, skin, hair, nails and teeth. The mesoderm is the middle layer of being divided embryo and it will develop into different organs of the fetus body, which includes muscles, reproductive organs, bones, heart and blood vessels. And the inner layer of this developing being will be formed into liver, bladder, lungs and digestive system.
Appearance in 4th Week Pregnancy
The dividend embryo appears to grow along the length; therefore the encircled clusters of the cells are transformed into a leaner figure. The ectoderm extends into a finger projected figure that is called villi. And it joins fetus with mother’s circulatory system.
A normal human body cell contains 46 chromosomes arranged in 23 pairs and these pairs are hereditary received from mother and father. After the cell division, each cell will carry equal number of chromosomes with having the same genetic information.
4 weeks pregnant women may experience urinary frequency, breast soreness, increased fatigue, faintness, morning sickness.