At the 11th week, the umbilical cord is fully formed and begins its function. It delivers all the mother's nutrients to the fetus and guarantees its nourishment. During this period, the intestines, which were still in the umbilical cord, now move into the fetus's abdomen. At the end of the 12th week, the first trimester is complete. The fetus weighs 28 grams and measures 8 centimeters. The small hands and feet now have fingers and can move, as well as mouth and eyes.

As the second trimester starts, the 4th month begins and the bothersome symptoms start to disappear. The belly already shows a small bump and in some cases, it's even possible to feel the fetus moving. At the 13th week, the fetus already has kidneys, which allow it to urinate the liquid swallowed in the uterus. Its head, which is disproportionally large compared to the rest of the body, now pauses in growth so the body can catch up. At the 14th week, hair and fuzz form on the fetus's body, and eyebrows also begin to develop.

By the 15th week it is already possible to see every detail of the body on ultrasound, even though the genitals are a bit difficult to see. At this stage, it is about 10 cm and weighs 50 grams. At the 16th week, the fetus is in a fast growth stage. By the end of this week, in addition to completing 4 months of pregnancy, the fetus weighs about 80 grams and can already play inside the uterus with the umbilical cord.

By the 5th month, the woman feels better and can eat and sleep more easily. The fetus, which previously moved almost imperceptibly, now makes more noticeable movements. At the 17th week, the pinkish skin becomes transparent. A layer of fat under the skin begins to develop to help regulate body temperature. At the 18th week, the fetus weighs about 150 grams and measures 14 centimeters. The ears are in the right place and hearing works perfectly.

At the 19th week, the sensory part of the brain starts functioning. The fetus can hear, see, taste flavors, and touch. At the 20th week, it is stronger and its genitals are clearly visible on ultrasound. This week, a substance called vernix⁴ appears all over its body to protect the skin, which is immersed in amniotic fluid. At the 21st week, completing 5 months, your baby measures 27 centimeters and can hear noises outside the uterus, beginning to recognize the parents' voices.

When the 6th month of pregnancy arrives, your belly, which took a while to grow, now has a round shape and gets heavier every day. Legs and feet tend to swell during this period. Therefore, rest and drinking plenty of fluids are essential to help. At the 22nd week, the baby already has eyelashes, eyebrows, and physical appearance very close to what it will have at birth. At the 23rd week, the focus of development is the lungs, which are preparing to breathe at birth. Wrinkled skin begins to stretch from the daily weight gain.

At the 25th week, the first fuzz on the head will have fallen out and hair grows in the color and texture it will have at birth. The body gains weight rapidly, weighing about 1 kg at the 26th week, at the end of the second trimester.

In the 7th month, anxiety is at its highest. After all, you are entering the third and last trimester of pregnancy. Fear and apprehension are common symptoms during this period. Lower back pain due to the weight of the belly is natural, along with leg pain.

At the 27th and 28th weeks, the baby continues to gain weight and prepares for birth. The accumulated fat helps to withstand the temperatures outside the uterus. In this phase, the baby can stay still for longer periods, taking naps throughout the day.

At the 29th week, the baby may turn and settle into the correct position for birth at any time. At the 30th week, the 7 months are complete and the baby responds more and more to stimuli, such as hearing the parents' voices or caresses on the belly.

The 8th month of pregnancy is when exhaustion hits. It seems like the baby's birth will never come. Tiredness and fatigue are inevitable. Swelling and insomnia are also frequent, increasing anxiety even more. Braxton Hicks contractions may begin as the uterus prepares for labor.

At the 31st and 32nd week, the baby will have doubled in size, weighing about 2 kilograms. Its body is completely prepared for birth, just needing to gain more weight. By the 33rd week, the bones are firm, except for the skull, which remains soft to make it easier to pass through the birth canal. At the 35th week, the baby's respiratory system is maturing. If the baby is born now, there is a good chance it will breathe without the help of medical equipment.

Finally, the 9 months have passed and the due date is getting closer and closer. The difficulty the mother had breathing improves, since the baby is dropping lower into the pelvis, relieving the pressure previously placed on some organs.

At the 36th week, the baby continues to gain weight and at the 37th week, parents can celebrate, as being born from now on is no longer considered premature. The vernix that covered the body begins to disappear. By the 38th week, the baby weighs on average about 3 kg and, even so, continues to gain weight. Its lungs are in perfect working order and meconium is formed.

At the 39th week, the transparent amniotic fluid⁵ becomes milky due to the vernix coming off the baby's skin and mixing with the fluid. Completing 9 months, you enter the 40th week and labor can start at any time. Symptoms such as cramps and diarrhea may signal that labor is beginning. Pregnancy can last up to 42 weeks and should be monitored by the obstetrician, with cardiotocography exams to track the baby's heart. If necessary, labor may be induced or even a cesarean section performed.

Photos: MIKI Yoshihito, Elvis Huang