Fetal Development Stages - Week by Week
When you are expecting a baby, nothing gives you more joy than to know what’s happening inside you and how your baby is growing. Understanding the fetal development is a very important aspect of preparing yourself for your pregnancy so that you can take care of yourself in a better manner.
Some soon to be mothers like to know the fetal development stages and others like to understand their fetal development week by week. Here is an overview of both.
Fetal Development Stages During Pregnancy
After the sperm enters the vagina and reaches the fallopian tubes...
Pregnancy And Baby Care Questions
...it fuses with the oocyte or the female egg to form a zygote.
- Zygote: The zygote is the single cell fusion of the sperm and the ovum. It contains the entire genetic material of both the parents and moves to the uterus. Here the cell division begins and the zygote converts into a ball of cells known as blastocyst.
- Blastocyst: The blastocyst continues to divide. It receives its nutrition from the mother’s blood.
- Embryo: After the early fetal development, the blastocyst enters a stage known as differentiation. In this stage, the ball divides into three layers. Each of these three layers goes on to form different organs. The outer layer forms the nervous system and skin, the middle layer forms the digestive and the respiratory system and the innermost layer forms the skeleton and the muscles.
Fetal Development Week by Week during Pregnancy
- In the third week of pregnancy, the nervous system, gastrointestinal tract and the heart begin to develop
- In the fourth and fifth weeks, the limbs begin to appear and the development of brain speeds up. The cranial nerves start to form. Eye and ears begin to appear and the vertebra begins to form. The main blood vessels are completely formed and blood begins to flow through the fetus.
- In the sixth week, the limbs continue to grow, digits begin to form on both limbs and the brain continues to develop. Lungs begin to appear.
- In the seventh week, hair follicles, joints, nipples and toes are completely formed. The essential organs begin to develop.
- In the eighth week, eyelids begin to develop, ear forms completely and the facial features become more marked.
- From the ninth week to the twelfth, the face and limbs are completely formed, red blood cells begin to get formed and the tooth buds start to appear. The baby is able to make a fist.
- From week thirteen to sixteen, hair on the head begin to develop, intestinal tract begins to form and the bones become harder. The baby begins to move and the digestive system begins to work.
- Around the seventeenth week, the baby begins to hear everything.
- In the twentieth week, hairs begin to form on the entire body, nails appear and the heartbeat of the baby becomes audible. Eyebrows and eyelashes also appear.
- In the ensuing weeks, the baby begins to flutter the eyelids and all normal bodily functions can be performed. The baby even starts to excrete. The fingerprints begin the form and the body becomes more proportionate.