During the sixth month of your pregnancy (from the 21st to the 24th week) you get the most pleasure from your pregnancy. Your weight continues to increase by about 0.5 kilogram per week. Looking at yourself in the mirror, you might be surprised at how much your body has increased over the month. The baby’s movements will become stronger and more frequent, and now your spouse and older children can also feel the little life within you.
Your baby’s muscles and skeleton continue to develop rapidly. Your child is actively moving away in your belly, and during the day, they can change their position in the uterus dozens of times: rightside up, upside down, horizontally, and doing soumersaults and flips. The availability of lots of room in the uterus for your little one aids in this, while moving around freely can be hindered later in the pregnancy when he/she grows.
Also, the hearing of the fetus develops so well that he reacts not only to loud and harsh sounds, but also to conversations and music.
At this stage of the pregnancy the gastrointestinal tract of the fetus keeps developing. Receptors on the taste buds of the tongue are also formed, allowing your baby to distinguish different tastes in the amniotic fluid. The taste in the fluid changes with what you, as the mother, eat.
As the mother, you will be feeling movements of your little one more intensely, and periods of sleep and wakefulness of the you and your baby may not always coincide. You may find herself waking up at night to the movements of the baby. However, these jolts won’t be very painful since the baby doesn’t have enough physical strength yet.
From week 21, the mother will start to gain weight rapidly due to the baby primarily accumulating muscle and fat mass. Your appetite may also be increasing.
Your baby’s skeleton is also developing, which requires an extra consumption of calcium-fortified foods. It is quite possible that at this period of your pregnancy your doctor will prescribe an additional calcium supplement to aid in the process.
Your baby’s height is now around 28–30 cm, and by the end of week 22 he/she will weigh around 500 g. The proportional ratio of the size of the head relative to the body continues to change – your little one is looking more and more like a newborn. From this period of pregnancy, your baby periodically begins to straighten their legs, which until then had been mostly in a bent state. Characteristic of this period is the intensive improvement of the central nervous system. In the period from 21 to 25 weeks of intrauterine development, the weight of the brain increases from 20 to 100 g – this is a very fast weight gain.
Your child is making more and more distinct subtle movements – they are curling and uncurling their fingers and turning their head in different directions. Your baby may be sucking a thumb, raising a hand to feel their face, or tilting his/her head. Such movements reflect quite a serious development in the central nervous system. This is shows that they have developed sensitivity and coordination, where they are able to clearly feel the position of their body in space.
A surprising fact: by 22 weeks in utero, the brain of your baby will contain a complete set of brain cells, called neurons. This number of neurons will be the exact same after birth and throughout their life. All the rest of the time, there will only be an increase in the connections made between these cells and an improvement in the functioning of the brain.
As for the future mother, the height of the bottom of the uterus by this period reaches 2 cm above the navel. Your organs change in their habitual location. future mothers often feel discomfort in the lower ribs area, which are slightly moved apart under the pressure of the uterus bottom. To get rid of this, you need to keep track of your posture, keeping your back straight. Moving around and changing the position of the body by bending, turning your body and doing simple exercises will help relieve pressure on the ribs.
Furthermore, during this period, due to the bottom of the uterus pressing on your stomach, the contents of the stomach, such as food soaked in acid, is thrown back into the esophagus. This can cause heartburn, where you can feel a heaviness and a burning sensation after eating. To prevent these unpleasant feelings, you should chew thoroughly, eat in small portions, and not go to bed immediately after eating.
Fetal development during this period is characterized by intensive formation of the respiratory system. From this stage on, your baby begins to make constant respiratory movements. Prior to this period, they occurred sporadically and did not last long, but now the breathing movements last up to 40 minutes. Their frequency is 50-60 per minute. This systematic training of the lungs will continue until delivery. With each movement that imitates inhalation, a certain amount of amniotic fluid enters the respiratory tract up to the closed glottis and is pushed out, washing the epithelium – the intestinal cells of the respiratory tract.
The child continues to ingest the amniotic fluid, the liquid part of which is absorbed into its bloodstream, and the rest forms meconium – your baby’s first feces. Sometimes intense ingestion of water by your child causes irritation of the diaphragm (the flat muscle that separates the chest and abdominal cavities) and its subsequent contractions.
This is manifested in the form of rhythmic movements called “fetal hiccups”. This phenomenon occurs frequently and is not a sign of trouble. As a rule, “hiccups” lasts several minutes and does not cause discomfort to either the mother or the baby. If it occurs frequently and lasts several hours, you should inform your doctor about it in order to exclude other causes of hiccups, such as fetal hypoxia.
An important event of week 23 is the improvement of the blood-forming organs and the immune system, thus, the liver, spleen, bone marrow, lymph nodes and the thymus. The thymus, or thymus gland, is the most important endocrine gland located behind the sternum. It intensively grows in the period of pre-natal development and with the onset of puberty it atrophies – decreases in size and ceases to function. Thymus can be called the “school of lymphocytes.” “Untrained” lymphocytes enter the tissue of the thymus, which undergo maturation in it and are released into the blood by adult T-cells – strong lymphocytes, able to resist foreign agents.
The infant’s own immune system during fetal development is only in still in an undeveloped stage unable to protect the baby by itself. The main role of protection is through the mother’s cells called antibodies. From the 23rd week, there is a “learning” of the baby’s immune system. The body of the baby learns to recognize antigens, such as foreign cells (bacteria, viruses, etc.), remembers them, and forms a protection against them.
At week 23, the height of the bottom of the uterus reaches 4 cm above the navel. Weight gain by this time is about 5–7 kg. It is very important to continue to monitor your diet in order to prevent excessive weight gain.
Due to the intensive growth of the uterus, the center of gravity shifts, and your spine and joints may ache when walking, in a sitting position, etc. You may realize that you may want to wear a pregnancy bandage or band to help alleviate the pain.
The height of your child at this time is around 33 cm, and the weight – 600 g. Your baby now occupies the entire space of the uterus, making its movements more distinct and less intense. The fetus is able to radically change its position from the head to the pelvic and vice versa, but prefers smaller movements, such as playing with the umbilical cord, and bending and stretching out its limbs. During this period, the number of muscle fibers increases dramatically and reaches its maximum. Furthermore, the increase in muscle mass will occur due to an increase in volume for each muscle fiber.
This period is also characterized by the improvement of your baby’s sensory perceptions. Skin, vestibular, gustatory, and auditory sensitivity has become more complex over the last few weeks and has reached a fairly high level of development by the end of 24 weeks. If a bright sunlight hits the belly of a pregnant woman, then the fetus turns away, blinks his eyes, or covers himself with his hands. In situations where the mother experiences anxiety or fear, or the baby hears loud or harsh sounds, the baby either reacts by moving intensively, or by stopping movement all together for some time.
For the mother, the weight gain by this period is around 500 g per week. A rather rapid weight gain can cause swelling of the feet, especially in the evening. It is important to rest your legs, and if possible, have them lifted up whilst lying or sitting. It’s best if you wear comfortable shoes. The use of special compression stockings or tights might help reduce the appearance of edema and prevent the development of varicose veins. Consult with your gynecologist whether wearing compression tights are necessary for you individually.