From the 13th week of pregnancy, you enter a new period for you - the second trimester, which is considered the easiest of the entire period of bearing a child. Early toxicosis is already over, the risk of abortion is minimal, and the stomach is not yet so big as to tire you with its heaviness.
Baby size: 60 - 80 mm.
Baby weight: 20 - 30 gr.
At the 13th week of pregnancy, your baby is about 6-7 cm tall and weighs 20-25 g. From this point on, the head will grow more slowly and the torso will grow faster.
What else is going on with your baby's body?
Circulation.
By the time of 12-13 weeks of pregnancy, the heart has four chambers, but, unlike the heart of an adult, it has a hole between the right and left atria. It "beats" with a frequency of 155 - 148 beats per minute.
Nervous system.
The fetus moves well, many reflexes are already developed: the baby reacts to touching the skin of the face, palms and heels, to loud sounds and bright light. Thanks to the development of tongue receptors, the child feels the taste of amniotic fluid.
Leather.
While it is very thin and translucent, with translucent blood vessels. However, by the 12th - 13th week of pregnancy, the rudiments of the sebaceous and sweat glands have already formed in it.
Bone system.
The bones of the baby are made of cartilage tissue, but gradually begin to harden. That is why it is very important for the expectant mother to get as much calcium as possible with food.
The immune system.
From the 13th week of pregnancy, B-lymphocytes (immunity cells) are formed in the bone marrow of the fetus, and immunoglobulins (antibodies) of all classes are synthesized in the blood. But despite this, the child's immune system is not yet active and cannot protect him from intrauterine infection.
Respiratory system.
The respiratory muscles of the fetus are already well developed, their contractions occur when the glottis is closed, so the amniotic fluid does not enter the lungs.
Digestive system.
By the 13th week of pregnancy, some enzymes are already produced in the baby's body, and the fetal liver is able to form bilirubin.
Endocrine system.
The pancreas produces insulin, a hormone that maintains normal blood sugar levels. And the thyroid gland synthesizes thyroxine, which is necessary for the growth and development of the body. Therefore, at this stage, the mother should receive a sufficient amount of iodine.
Kidneys.
The urinary system of a child at the 13th week of pregnancy is already functioning: the kidneys produce approximately 2.2 ml of urine per hour.
Sexual system.
In girls, follicles are laid in the ovaries; in boys, the process of moving the testicles into the scrotum begins, which will be completed by birth.