Categories embryo development

Fetal formation in the third month

Fetal formation in the third month

Pregnancy

The period of pregnancy is nine months and is divided into three periods. The first period lasts from the first month to the third month, from the first week to the twelfth week. The second period extends from the 13th week to the 27th week. The third period starts from the twenty-eighth week To the end of pregnancy, and each stage of pregnancy and hormonal and physiological changes, imposed by the presence of the fetus, which continues to develop and grow during the various months of pregnancy.

Fetal formation in the third month

In the third month of pregnancy, between the ninth week and the twelfth week, the following changes occur in the fetus:

Week Nine

Changes in the fetus in the ninth week include the following:

  • The size of the embryo is the size of a grape, and it is 25.4 mm long and weighs a fraction of an ounce, but it will be able to gain more weight quickly in the coming weeks.
  • The heart consists of four chambers, and the valves begin to form.
  • The embryonic tail disappears.
  • Genitals are made up, although the fetus’s sex is not yet determined.
  • The eye is formed, but the fetus’s eyelid is still contagious, and will remain so until the 27th week.
  • The internal structure of the fetus becomes a component of bone rather than cartilage.
  • The head becomes more round, more moderate, and the neck more sophisticated.
  • The fetus begins to move, although the mother may not feel movement.
  • The taste buds are formed.
  • The limbs were formed and the toes and legs were distinguished, and the fetus became able to bend the elbow.
  • External ear is completed.
  • The spleen, liver, and gall bladder are formed, while the intestine is still in transition from the umbilical cord to the abdominal cavity of the fetus.

Week 10

Changes in the fetus during the 10th week of pregnancy include the following:

  • The tooth begins to form under the gums.
  • The length of the fetus is between 1.25 – 1.68 inches (31.75 – 42.67) millimeters, and its weight is still less than a quarter ounce (less than 7 grams).
  • The knees and ankles begin to develop.
  • The intestine is now in the abdominal cavity, and most organs in the abdominal and pelvic cavity begin to function. The stomach produces digestive juices, the kidneys produce more urine, the liver excretes the bile, and the pancreas begins to secrete insulin.
  • Male embryos become able to secrete the testosterone, and the genitals begin to differentiate.
  • The nails appear.
  • The structure of the brain is complete, and its mass increases.
  • The fuzzy hair begins to form on the skin.
  • The spine is formed, and appears through the transparent skin, and the spinal nerves extend from the spinal cord.
  • The length of the head becomes about half the length of the body, due to the growing growth of brain size.

Week Eleven

Changes in the fetus in the eleventh week include the following:

  • The length of the fetus is 1.5-2 inches (38.1 – 50.8) mm, and its weight is approximately one third of an ounce (9.3) grams, the size of the fig.
  • The length of the head is similar to the length of the body.
  • Taste buds continue to form, the tongue forms, and the nasal passages become open.
  • Nipples appear.
  • Hair follicles are formed.
  • Bone starts with sclerosis.
  • The hands and feet become in front of the body.
  • The fetus becomes able to roll, and the intracellular clotting.
  • The embryo’s body takes a straight position.

Twelfth week

There are many changes in the fetus this week, including:

  • The length of the fetus is 2.5 inches, or 63.5 millimeters, and weighs about half an ounce, approximately 14 grams.
  • The head of the fetus this week is based on the neck instead of the shoulders, and it is about half the size of the body.
  • Salivary glands begin to function, forming sweat glands.
  • The mother can hear the fetal heartbeat using an external doppler (Doppler).
  • The embryo starts by inhaling and exhaling the amniotic fluid (breathing with amniotic fluid).
  • The spleen, the liver can get rid of damaged red blood cells, produce antibodies, and the bone marrow begins to produce white blood cells, and the pituitary gland begins to manufacture its hormones.
  • Male and female members appear clearly.
  • The muscles and nervous system continue to mature.
  • Body hair grows.

Medical examinations during the first months of pregnancy

Of the tests that may be required of pregnant women during the first three months of pregnancy:

  • Blood group examination, and the Rayse factor.
  • Blood tests to detect the presence of certain diseases, such as: anemia, hepatitis B, sexually transmitted diseases such as syphilis, and HIV, in addition to confirming the immunity of the pregnant woman to measles.
  • Blood tests to determine the possibility of the fetus to have some genetic disorders such as: cystic fibrosis, Tay-Sachs disease, and sickle cell anemia, in the presence of risk factors, such as a family history of these disorders.
  • Check the level of pregnancy hormone (HCG), a hormone produced by the placenta, and progesterone hormone.
  • Examine a sample of urine to ensure no infection in the kidneys.
  • Diabetes screening.
  • Examination of albumin protein to ensure that the pregnant woman is not exposed to pre-eclampsia and high pregnancy stress.
  • Genetic tests to ensure that the fetus is not infected with Down’s syndrome and other chromosomal disorders, although many pregnant women may not want to conduct such tests, and genetic tests include the following:
    • A blood sample was tested to measure the level of the pregnancy hormone (HCG) and to examine the plasma-associated plasma protein (A).
    • Nuchal translucency examination: In which the skin is photographed in the fetal neck from the back using ultrasound.
    • Examination of placenta sample (CVS).
    • NIPT: A sample of the mother’s blood to measure the relative amount of DNA in the mother’s blood.