Development of the Fetus in the Womb Every Week
Did you know that the development of the baby in the womb goes very fast? The fetus learns a lot and even does various things in the womb that are included in the stage of development in the womb. The following is information on the development and growth of the fetus while in the womb:
The development of the fetus in the womb at the age of one week
Calculation of gestational age starts from the first day of the last menstrual period (HPHT) – before the end of menstruation can be said to be late. Therefore, it can be said that in the first and second weeks, you have not actually experienced pregnancy. So what happened this week?
Launching from WebMD, after experiencing the fertilization process, namely the meeting of eggs with sperm, a network of 100 cells will be formed which will later become the embryo of the fetus. After dividing and multiplying cells, the prospective fetus or embryo will stick to the uterus, which is where its growth and development occurs during pregnancy. This is where the development of the fetus in the womb begins.
The development of the fetus in the womb at the age of two weeks
Entering the second week, the development of cells in the embryo is owned by approximately 150 cells that form three layers, namely endoderm, mesoderm, and ectoderm which will later become the fetus. The layers formed by these cells will become the various organs and body parts of the baby, such as muscles, bones, heart, digestive system, reproductive system, and nervous system.
The development of the fetus in the womb at the age of three weeks
During the development of the fetus in the womb, the embryo successfully attaches itself to the uterus. At this time, the embryo is still doing cell division and multiplication, therefore it is not yet shaped like an embryo or a baby. The outer layer of the embryo will form the placenta or placenta.
At this stage too, various organs of the body begin to form, such as the brain, spine, thyroid gland, heart organs, and blood vessels. The size of the embryo at the third week is still very small, only 1.5 mm.
The development of a baby at four weeks of age
The heart is formed and starting to function and the blood vessels have their own flow of blood. In addition, it has begun to form the hands and feet. At week 4 the size of the embryo is 5 mm, according to the development of the fetus in the womb.
The development of a baby in the womb at five weeks of age
The development of the baby in the womb is getting better. The baby’s hands have started to grow, but they are still not shaped like hands, they are still flat without fingers. The basic structures of the brain and nervous system have also been formed, while new eyes, ears and mouth will be formed. The size at week 5 was 7 mm.
The development of a baby in the womb at six weeks
Entering week 6, the size of the embryo is as big as a pea or about 12 mm. The development of the feet of the prospective fetus has begun to grow in the womb, even though the toes are not yet formed. The digestive system is just starting to grow. While the upper lip and palate are formed. The head of the embryo is already visible but its size is very small, and it is seen that the ears and eyes are being developed.
The development of a baby in the womb at seven weeks
The size of the embryo when entering the 7th week is about 19 mm, this is in accordance with the development of the prospective baby in the womb. At this stage, new lungs will be formed, fingers are visible, and muscles and nervous system are functioning properly. Therefore, at this time, the embryo can already show its reflexes to its mother.
The development of a baby in the womb at the age of eight weeks
At the development of the 8th week of pregnancy, the embryo in the womb can already be called a fetus because it already has a human-like face and shape. The eyelids and nose begin to form this week.
At this stage, the placenta develops and the fetus is surrounded by amniotic fluid which is formed from the blood vessels of the mother. The amniotic fluid serves to maintain a normal fetal temperature, helps the fetus move, and helps in the development of the fetal heart. The size of the fetus reaches 3 cm or the size of a plum at week 8.
The development of a baby in the womb at nine weeks
The face of the fetus is more and more clearly formed. The eyes are bigger and more colorful, according to the pigment that each fetus has. The fetus is able to open its mouth and the vocal cords and salivary glands begin to form. A 9-week-old fetus is the size of a limo or about 5.5 cm.
The development of a baby in the womb at 10 weeks
A 10-week-old fetus measuring 7.5 cm, has a head that is bigger than its body size. The heart is working perfectly. The fetal heart beats 180 beats per minute, two or three times faster than the normal heart rate in adults. Bone cells are first formed, replacing cartilage that was previously formed.
The development of the fetus in the womb at 11 weeks
The facial bones are starting to form, the eyelids are still closed and won’t open for the next few weeks. Nails have also begun to form. This week, it turns out that the fetus is able to swallow and excrete urine, which is excreted in the amniotic fluid.
The development of the fetus in the womb at 12 weeks
After 12 weeks from the last period of your period, the organs and body systems present in an adult are owned by the fetus. The organs, muscles, glands, and bones are perfectly formed and begin to function. Starting from this week, there will be the development and maturation of various organs that have been formed previously. The fetal spine, which was formed from cartilage, at week 12 will turn into hard bone.
The development of the fetus in the womb at the age of 13-17 weeks
When entering the 13-17 week age, the fetus weighs 57-113 grams and is about 10-13 cm long. The fetus has a dream at this stage, it can wake up and then sleep. In addition, the fetus’s mouth can also be moved, such as being opened or closed. At week 16, the sex of the fetus can be seen, whether it is male or female can be helped to see by doing an ultrasound. The appearance of fine hairs on the head, which is known as lanugo.
The development of the fetus in the womb at the age of 18-22 weeks
The size of the fetus has reached 25 to 28 cm and weighs 227 to 454 grams. At this stage, the existing and hard bones have replaced the cartilage bones in the fetus. The fetus begins to hear and respond to movements. Therefore, the mother can feel the kicks, punches and various movements of the fetus. The oil glands in the skin start to work.
Fetal development in the womb at 23-26 weeks of age
The fetal pancreas begins to work effectively and the lungs are more mature at this stage. Babies born when entering week 23-26 have a greater chance of survival, compared to previous weeks. Eyelashes and eyebrows began to appear.
Fetal development in the womb at the age of 27-31 weeks
It is estimated that 91% of fetuses born at 27-31 weeks can survive despite the risk of various complications such as birth defects and low birth weight. Basically, all organs and body systems are mature at this age and will continue to develop until birth occurs.
Fetal development in the womb at the age of 32-36 weeks
The movements and kicks made by the fetus are getting stronger and more pronounced. At this time, the fetus’s skin is pink and very smooth. A fetus at this age weighs 1.814 to 2.268 grams and a length of about 41-43 cm.
Fetal development in the womb at 37-40 weeks
This week is the last weeks of pregnancy. Currently the fetal weight has reached 2.722 to 3.639 grams and body length is around 46 cm. In male babies, the testicles are fully formed and covered with a scrotum. When entering the 40th week, the fetus is ready to be born and all organs are formed and functioning properly.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Keith L. Moore, The Developing Human – Clinically Oriented Embryology, WB Saunders Company, 4th edition, 1998. •
South Dakota Department of Health. 1995. FETAL GROWTH AND DEVELOPMENT
Cold, F., Health, E., Disease, H., Disease, L., Management, P., & Conditions, S. et al. (2020). Your Pregnancy Week by Week: Weeks 1-4. Retrieved 6 February 2021, from https://www.webmd.com/baby/guide/your-pregnancy-week-by-week-weeks-1-4#1
Your pregnancy week by week. (2017). Retrieved 6 February 2021, from https://www.nhs.uk/conditions/pregnancy-and-baby/pregnancy-week-by-week/
