The shape of the fetus in the fourth month of pregnancy

+ Font Size -

The shape of the fetus in the fourth month of pregnancy


The shape of the fetus in the fourth month of pregnancy


The fourth month begins in the fourteenth week of pregnancy and ends in the seventeenth week. Below we explain in detail how the shape of the fetus changes during these weeks:


Fourteenth week


During the fourteenth week of pregnancy, the fetus undergoes many changes, and the following are the most prominent statements of these changes:

  • The size of the fetus during this week of pregnancy is the size of a lemon; It is about 9 cm long and weighs about 43 grams. 
  • The fetus's organs begin to differentiate in the fourteenth week of pregnancy, so when examining the fetus, its arms, wrists, and hands look fine except for the fingers. The eyes appear as dark areas behind the closed eyelids where the eyes move to the sides. See from the inside. 
  • At this stage, the length of the arms and legs increases, and the fetus can move freely, but the head is larger and the forehead is slightly swollen compared to the size of the fetus. 
  • The nasal bones appear only from the bridge of the nose, and the lower jaw begins to appear, except for the fact that the umbilical cord originates in the center of the abdomen. 
  • Thinning hair or fluff begins to cover the fetus's body, and at birth, these hairs disappear to warm it in the womb. 
  • The fetal kidneys begin to function; When the fetus begins to swallow a small amount of surrounding fluid (called amniotic fluid), this fluid enters the fetus's stomach and is excreted as urine.
  • The mother begins to notice the movement of the fetus significantly as the fetus begins to expand and begins to practice breathing by entering the amniotic fluid and expelling it from the lungs. 
  • The fetus begins to show reflexes when it responds by stretching or opening on its own when the abdomen is touched. 
  • The external genitalia may already have formed by this time in pregnancy. 
  • The digestive system begins to develop as the intestine secretes the so-called meconium; It is the main waste product of the newborn after birth. 
  • The liver begins to produce bile. 
  • The thyroid gland begins to produce hormones.
  • If the fetus is male, the prostate is formed during this stage of pregnancy, in females, ovarian follicles begin to form. 


Fifteenth week

The shape of the fetus in the fourth month of pregnancy


Many changes occur to the fetus during the fifteenth week of pregnancy, and the following are the most prominent expressions of these changes:

  • The fetus is about 9.5 cm long and weighs about 80 grams. 
  • The skin of the fetus is thin and tends to be transparency so that the blood vessels can be seen through it, and the muscles of the fetus are getting stronger and stronger at this stage of pregnancy, and this can be seen through the feeling of the mother. . Fetal kicks and movements, and the fetus's face begins to show different expressions.
  • The eyelashes and eyebrows of the fetus begin to appear. 
  • The work of both the digestive and respiratory systems of the fetus is developing, as the fetus begins to practice sucking and swallowing movements to draw the amniotic fluid and expel it through the lungs, which helps in the growth and development of the lungs. 
  • The fetus's bones begin to harden and muscle tissue continues to grow, allowing the fetus to begin to stretch more, and while its legs are still short, it continues to grow in length. 
  • The ear bones begin to form, and the fetus begins to hear the internal sounds surrounding it, including the mother's voice as well as the sounds of her heart and digestive system, and the fetus begins to perceive and respond to light, although its eyes remain closed. 
  • The fetus develops a fist and can suck its thumb. 
  • The fetus may experience hiccups this week, and the mother may experience them later during pregnancy. 
  • By the end of the 15th week of pregnancy, the fetus can practice most of the body's movements, such as moving hands and feet, stretching, and breathing. 
  • This week, the size of the fetal head becomes smaller than the size of the body, which is an important growth difference in the growth of the fetus.

Sixteenth week

The shape of the fetus in the fourth month of pregnancy


During the sixteenth week of pregnancy, the fetus undergoes many changes, and the following are the most prominent statements of these changes:

  • The length of the fetus is about 11.6 cm and weighs about 100 grams, which is the size of an avocado. 
  • The fetus begins to grow rapidly, which is called a growth spurt, which leads to a doubling of the fetus during the next month. 
  • The scalp is beginning to form, although the fetus is not yet fully formed. 
  • The umbilical cord is fully formed and the fetus can hold it with a fist, knowing that at this stage the fetus can respond either in the face or in the muscles, but it has not yet controlled them. 
  • The nervous system continues to develop, the fetus can move its arms and legs, and the mother may begin to feel the fetus's kick.
  • The taste buds begin to grow and function during this week, so the fetus can feel the taste of the amniotic fluid when swallowing. It should be noted that the amniotic fluid tastes the food eaten by the mother, so during this week, the fetus may begin to differentiate between food and prefer one food over another.
  • Bones and muscles continue to grow to form bone.
  • During this week, the fetus's head is more proportional to the shape of the body.
  • Hair begins to appear on the eyebrows, upper lip, and chin. 
  • The first eye movement begins between 16-18 weeks under the closed eyelid, and with the first eye movement, the fetus begins to touch its eyelid. 

Seventeenth week

The shape of the fetus in the fourth month of pregnancy


During the seventeenth week of pregnancy, the fetus undergoes many changes, and the following are the most prominent statements of these changes:

  • The length of the fetus is about 12 cm and weighs about 150 grams, which is about the size of a pomegranate. 
  • The fetus can respond to loud sounds.
  • The baby's fingernails begin to grow.
  • The fetus can open and close its mouth.
  • The fetus can move its eyes, but they remain temporarily closed.
  • Fingerprints began to form, indicating that even in the case of an identical twin pregnancy, the fingerprints cannot be identical. 
  • The fetus's body now begins to form fatty tissue that begins in the lining of the face, neck, chest, and stomach, then the back, shoulders, arms, and legs. Adipose tissue performs many important functions in the body; They store energy and maintain temperature The body, in addition to protecting the internal organs, contributes to the formation of the characteristics of the fetus.
  • As the soft cartilage begins to turn into bone, bone stiffness increases. 
  • The sweat glands begin to appear and form.
  • At this stage, the reproductive organs are fully developed, so doctors can use ultrasound or so-called ultrasound to detect the sex of the fetus at this stage of pregnancy. 
  • The fetus's kidneys are already working because the fetus excretes urine approximately every 50 minutes.
  • During this week of pregnancy, the taste buds are working well and the fetus can distinguish between sweet and bitter. 
  • The umbilical cord and placenta both grow and the length and thickness of the umbilical cord increase, while the placenta expands and blood circulation increases to provide the fetus with the oxygen and nutrients it needs. 

Symptoms of pregnancy in the fourth month

The shape of the fetus in the fourth month of pregnancy


During the fourth month of pregnancy, a pregnant woman notices the disappearance of some of the first signs and symptoms of pregnancy; For example, a pregnant woman's nausea often disappears by the fourth month,  

but the mother may begin to feel it during this period, and the pregnancy is not limited to feeling bloated and tired, as the size of the uterus increases during this period. 

After months of noticeable changes, the mother began to notice that her clothes became tight, and the following are statements of the most prominent symptoms of a pregnant woman in the fourth month of pregnancy: 

  • Heartburn and indigestion.
  • Stretch marks begin to appear.
  • shortness of breath.
  • Feeling pain in the back.
  • constipation;
  • Increased appearance of blood vessels called varicose veins.
  • Nasal congestion and swelling.
  • The mother may begin to suffer from round ligament pain; a Sudden feeling of sharp pain on both sides of the abdomen.
  • Suffering from irritation or bleeding in the gums.

Article Summary


The fourth month of pregnancy ends from the fourteenth week to the seventeenth week, and this stage witnesses many changes in the fetus. His genitals are fully developed, 

and it should be noted that some symptoms, such as dilated skin tags and varicose veins, begin to appear during this stage, although some of the initial symptoms of pregnancy, such as nausea, disappear.