Prenatal development is the growth of the baby inside the womb. This growth cycle is divided into a nine-month period. If you want to know more about the stages of prenatal development, read along.
Stages of Prenatal Development
Prenatal development is divided into three stages known as the germinal stage, embryonic period, and the fetal period. The first two weeks immediately after conception are termed as the germinal stage. The third through the eight weeks is the embryonic period while the period from the ninth week until the birth of the baby is known as the fetal period.
When the sperm unites with an egg cell to form a zygote, this process is known as the germinal stage. The fertilization of the egg takes place in either of the fallopian tubes, after which, it moves towards the uterus. This is a week-long process. Cell division starts 24 or 36 hours after zygote formation. The zygote quickly divides into two, four, eight, and so on, number of cells. As soon as the zygote divides into eight cells, each one takes a certain characteristic. The division from this stage occurs rapidly. The cell then reaches the uterus and gets attached to the uterine wall. This is known as implantation. Soon, the woman’s menstrual cycle is halted and she undergoes a lot of physical and hormonal changes.
From the third stage onwards, the zygote is now known as an embryo. It is now that the cells can be identified as a human. During this stage of prenatal development, the brain develops. The nerves and the spinal cord begin to develop during this phase. The head forms in the fourth week and the eyes, nose, ears, and mouth quickly develop. Arms and legs develop in the fifth week. By the eight weeks, an embryo has all the parts of a human body apart from the sexual organs.
From the ninth week, the embryo is known as the fetus. The body continues to develop in this phase. The fetus begins reflexive movements with its legs and arms. The sex organs form and the fetus grows in height and weight. This phase is also known as the end of the first trimester of pregnancy. In the second and third trimester, the heartbeat gets stronger and the body develops fully. The nails, hair, eyelashes, toenails, etc. also develop at this time.
It is wonderful to learn and see how a zygote transforms from a fertilized egg into a fully developed baby. It is a miracle of nature. Most women feel nauseous and sick in the first trimester when the maximum development takes place. In the later stages, the body of the baby develops internally and externally. Doctors can determine the sex of the baby at the end of the first trimester. It is very necessary for a pregnant woman to eat well and sleep well during her pregnancy to ensure proper nutrition to the fetus. Many miscarriages occur when proper care is not taken.