The prenatal stage is the period before birth; it is divided into three periods: germinal, embryonic, and fetal.
The germinal period covers the first two weeks after conception (hyperlink). During this stage, the zygote, the fertilized ovum, (hyperlink), attaches itself to the uterine wall. The embryonic period begins from the implantation until around eight weeks after conception. This stage is very crucial as it is when the various body systems and organs are beginning to form.
At 6 weeks of pregnancy, the embryo already has a developing head, discernible eyes and ears, and a beating heart with two chambers. At around 7 weeks, nostrils, arms, and legs can already be seen; also, the heart has already four chambers.
The fetal stage begins at about the eighth week until the ninth month of pregnancy. By three months of pregnancy, the fetus’ body is fully formed including the differentiation of the genitals. During the fourth month, the baby may already be thumb sucking and appear quite human. By the fifth month, the baby can be felt moving a lot. By the sixth month, the baby’s appearance is almost how it would like when it will be born. Finally, further developments occur such as fat deposition under the skin (7th month), maturation of the respiratory system (8th month), and positioning of the baby for birth (9th month).