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Weeks of pregnancy (SSW)
We want to inform you on our pages about a normal pregnancy. Here you will find important details, events and occurrences for each week of pregnancy of your child.
Please select the desired week of pregnancy in the following table:
TRIMENON
The first 13 weeks of pregnancy are called the 1st trimester. They begin after the last menstruation. The development of the child and the changes in the woman begin. During this period, folic acid prophylaxis is started (reduces the risk of open back), if it has not been started yet. The 2nd trimester is the period between the 14th and the 26th week of pregnancy. The period between the 27th and 40th week of pregnancy is called the 3rd trimester.
2. SSW (WEEK OF PREGNANCY)
The egg matures in the ovaries, and ovulation occurs at the end of the week. Fertilization takes place at about this time.
3. SSW (WEEK OF PREGNANCY)
Ovulation occurs about 14 days after the first day of the last menstrual period. About two hours after sexual intercourse, the sperm have overcome the 17 to 18 cm distance to the egg. Approximately one day after fertilization, the first cell division begins. About three or four days after fertilization, the egg has reached the uterus via the fallopian tube and begins to settle down. It does this by allowing the mucous membrane of the uterus to cover it and establish the first "connections" to supply it. Five to six days after fertilization, the fertilized egg nests in the uterus.
4. SSW (WEEK OF PREGNANCY)
The amniotic fluid is formed. The diameter of the fertilized egg is about 0.2 mm - the size of a dot. The fertilized egg has finally settled into the uterine lining so that the embryo, yolk sac and amniotic cavity are completely covered. A fibrin plug closes the hole to the uterus. The placenta forms. The embryo can now take in oxygen and nourishment through the placenta.
5. SSW (WEEK OF PREGNANCY)
In the 5th SSW, a head and tail part can be seen. The appearance of the embryo changes as the head grows and the face and limbs are laid out. The spinal cord, which is still exposed up to this point, is in the process of closing. The first blood cells and blood veins develop. A tubular heart has formed and will now begin to beat. The arm and leg systems are formed. They appear as paddle-shaped buds. At this point, the woman's menstrual period is about 1 week overdue.
6. SSW (WEEK OF PREGNANCY)
In the umbilical cord leading to the placenta, blood vessels connect to the mother. The eyes and mouth develop on the face. Lower jaw and vocal cords take shape. The mouth opening is created. The inner ear is formed. Now the embryo's organs begin to develop. The heart beats with a chamber. Blood cells are formed and circulate with the heartbeat. A vaginal wall forms in the heart. The development of the intestinal system, with an anterior, middle and posterior intestine begins. The umbilical cord emerges. The following organs develop: Lungs, liver, pancreas and thyroid gland.
First prenatal examination: In addition to a gynecological examination, ultrasound is used to confirm the pregnancy and its exact age. A blood test provides information about childhood illnesses, toxoplasmosis, blood group and other diseases important for pregnancy, such as hepatitis and HIV.
7. SSW (WEEK OF PREGNANCY)
The large joints, such as shoulders, elbows, hips and knees are clearly visible. Furrows form on the end parts of the limbs in the 7th week of pregnancy, from which fingers and toes later develop. The hands and feet can be distinguished as small buds. The wrist and fingers are now formed. The internal organs are almost complete. Bone cells develop where previously there were only cartilage cells. The anterior intestine gradually develops into the stomach. The face gradually takes shape. The eyes now become visible as small depressions on either side of the head.
8. SSW (WEEK OF PREGNANCY)
The formation of the heart is complete. The fingers and toes are now clearly visible. The upper lip as well as the tip of the nose are formed. The eyelids become visible.
Fetus size: 14 mm
9. SSW (WEEK OF PREGNANCY)
The sitting size of the embryo is measured from the coccyx to the head. The feet and hands become visible. The feet are now two millimeters long. The neck is taking shape. The formation of the body muscles is soon complete. The jaws are fully developed. The oral cavity and nose are united. Ears and nose are emerging. The sexual organs can be seen.
Size: XX
Seat height: 17-22 mm
10. SSW (WEEK OF PREGNANCY)
The head is still very large compared to the body. The ears find their final place on the side of the head in the 10th SSW and their shape is recognizable. The fetal heart sounds and the embryo are recognizable. The fingers and toes are now clearly distinguishable. The formation of the taste buds begins. The anlage for all 20 milk teeth can be seen, although still indistinctly. In male fetuses, the male testosterone hormones are formed in the testes.
Another examination is due: ultrasound is used for initial screening, and the child's nuchal fold is also measured. Together with the determination of special blood values, the individual risk for trisomy 21 (Down syndrome) can be determined.
If necessary, a chorionic villus biopsy can now be performed.
Size: XX
Seat height: 28-30mm
11. SSW (WEEK OF PREGNANCY)
Now, by and large, all the major organs of the fetus are developed and only need to increase in size. The heart pumps blood to all parts of the body. In the 11th week of gestation, the internal sex organs (testicles or ovaries) are formed. The external sex organs are developed to such an extent that the sex of the child can be determined with an external examination, e.g. ultrasound.
Size: XX
Seat height: 45mm
12. SSW (WEEK OF PREGNANCY)
The face now clearly resembles that of a human. From the 12th week of pregnancy, closed eyelids are visible. Due to increasing muscle growth, the child begins to move spontaneously. However, the movements are still too weak to be perceived. Brain activity and muscle work are coordinated and the joints contract. Fingers and toes are fully formed and have nails. Foot length is just one centimeter. The baby can suck and is able to swallow amniotic fluid. The pancreas begins to function and produce insulin.
Size: 70mm
Seat height: 60mm
BPD: 17mm
Weight: 28g
13. SSW (WEEK OF PREGNANCY)
The bone tissue forms and the ribs become clear. The nose and chin are clearly visible. The movements are gradually perceived. The fetus begins to suck its thumb. The fetus can open and close its mouth. The development of the external sexual organs is now complete. The sex of the fetus can therefore be clearly determined.
Size: XX
Seat height: 80mm
BPD: 21mm
Weight: 37g
End of the first trimester. The risk of miscarriage is now very small.
2nd trimester
14 - 17. SSW (WEEK OF PREGNANCY)
Routine check-up: in addition to weight, blood pressure, urine and blood, the baby's heart tones are checked. If necessary, an amniocentesis can be performed for genetic testing of the child.
14. SSW (WEEK OF PREGNANCY)
The eyes gradually move to their proper facial position. The cheeks become visible. The nose becomes more prominent. The first hairs become visible. The ears have taken the right position and acquired the right shape. The kidneys produce urine. In female fetuses, the ovaries move to the pelvic area.
Size: XX
Seat height: 90mm
BPD: 25mm
Weight: 45g
15. SSW (WEEK OF PREGNANCY)
Your baby can move his arms and clench his hands into fists.
From this week on, your child gets a real baby face. The facial muscles develop and form the wrinkles of the nostrils and the shape of the lips. Now his first facial features are also developing.
The child's lips open and close, he raises his eyebrows and turns his head. Now also the search and suck reflex sets in, which it needs at the latest as a newborn.
Size: XX
Seat height: 10cm
BPD: 29mm
Weight: 60g
16. SSW (WEEK OF PREGNANCY)
The fingernails have formed. The baby can frown, turn its eyes and swallow. Your uterus weighs about 250g and the amount of amniotic fluid has increased to 250ml.
The fetus has enough space to swim around freely in the amniotic fluid and exercise its bones and muscles. By the 7th month, the amount of amniotic fluid increases to 800ml to 1 liter.
The very thin and transparent skin of the fetus is covered with a fuzz all over the body, which disappears shortly before birth. The hair on the head and the eyebrows become coarser and remain after birth.
Size: 16 cm
Seat height: 11.6 cm
BPD: 32mm
Weight: 110g
17. SSW (WEEK OF PREGNANCY)
The feet are about two centimeters long. A heat-regulating layer of fat forms on the surface of the embryo's body. In addition to the fatty tissue, your baby is currently growing finger and toe nails. These are still very short, so it cannot scratch itself yet.
The tubular bones are branching, but much of the skeleton is still cartilage, which is more pliable and malleable than bone.
Size: XX
Seat height: 12 cm
BPD: 36mm
Weight: 115g
18. SSW (WEEK OF PREGNANCY)
The retina in the eye now reacts to light. The first stool (meconium) accumulates in the intestines.
Your baby moves and alternates between lying head down or up. The more the baby moves, the better its brain is stimulated. This is because the movements are coordinated there. The division of the nerve cells is complete and fluid is produced via small blood vessels that surround the brain and spinal cord.
Size: XX
Seat height: 14 cm
BPD: 39mm
Weight: 223g
19. SSW (WEEK OF PREGNANCY)
The skin now forms a protective wax layer (vernix). The baby swallows about 12 ml of amniotic fluid in 24 hours. What your baby drinks, it excretes back into the amniotic fluid as urine. In 24 hours, it thus produces 15-17 ml of urine. However, since the amniotic fluid is constantly renewed, the baby always gets enough fresh amniotic fluid to drink.
Size: XX,
Seat height: 15cm
BPD: 43mm
Weight: 273g
20. SSW (WEEK OF PREGNANCY)
Some women, especially second and third-time mothers, can now feel their baby. Toenails form. Hair growth begins on the rest of the body. The skin becomes thicker. Your baby is also developing its own sleep and wake rhythms. This does not always coincide with your own.
Although the heart formed a partition with two chambers and two atria in the previous month, an oval opening remains in the partition between the atria. This allows blood to flow from one atrium to the other without entering the lungs. Only at birth does this opening close.
2. screening examination with ultrasound: all organs are checked, the extremities are carefully inspected and growth is checked. The question of which hospital you would like to give birth in is now slowly becoming topical. Register for a guided tour in the birthing room of your corresponding hospital.
Size: XX
Seat height: 16cm
BPD: 46mm
Weight: 331g
21. SSW (WEEK OF PREGNANCY)
Now the baby is rapidly gaining weight. In girls, the vagina is formed and the ovaries already contain over six million eggs. In boys, however, sperm is not yet formed.
The organ of balance in the inner ear is fully developed. Through its sense of balance, your baby is able to detect its position in space. It provides the baby with information about the position of muscles and joints, enabling him to perceive himself.
The influence of the environment on the baby increases. The little explorer now also begins to use his hands to scan his surroundings. At the beginning of the 6th month, the child gradually has a more open ear for its surroundings and can perceive sounds.
Size: 30cm
Seat height: 17cm
BPD: 50mm
Weight: 398g
22. SSW (WEEK OF PREGNANCY)
The child responds to sounds and develops a sleep-wake rhythm. It may be awakened by the mother's movements. Sounds from outside, such as your or your partner's voice or music, are muffled by the amniotic fluid but can be heard clearly. The sounds of your body, your heartbeat, your voice also become familiar to the fetus. Your child learns to distinguish between certain sound patterns, it can feel and hear. Thus, his awareness of his environment increasingly awakens.
Size: XX
Seat height: 18 cm
BPD: 53mm
Weight: 478g
23. SSW (WEEK OF PREGNANCY)
If your baby were born now, it would have a (small) chance of surviving. The baby can now suckle and eyebrows are visible.
Its wrinkled skin becomes smoother as it gains weight. The downy wool hair takes on a darker coloration these days and more hair grows on the skull. The baby's fingernails now cover the fingertips.
Size: XX
Seat height: 20cm
BPD: 56mm
Weight: 568g
24. SSW (WEEK OF PREGNANCY)
The baby is now gaining 85 grams per week. The eye lashes are clearly visible.
The amount of amniotic fluid now continues to increase to reach about 1 liter at 36 weeks. The composition of the water is also changing. While it initially resembled more of a serum, the water now contains dead cells, wool hair, and skin gunk. Although the amount of amniotic fluid continues to increase, the baby has less room to move.
At about 30 cm long, it begins to take up most of the available space. The baby can change its position. It sits down, wraps its arms over its chest and pulls its knees up to its belly.
Size: 30cm
Seat height: 21cm
BPD: 59mm
Weight: 670g
25. SSW (WEEK OF PREGNANCY)
The sexual organs are fully developed.
Another examination is due: You must appear for this examination fasting, as the blood sugar is determined. If the value is elevated, a blood sugar disease during pregnancy must be ruled out. If you have a Rhesus negative blood group, antibodies can now be injected to prevent Rhesus disease.
Size: XX
Seat height: 22cm
BPD: 62mm
Weight: 785g
26. SSW (WEEK OF PREGNANCY)
The feet are five centimeters long. The baby can now open and close its eyes.
An irregular or arythmic heartbeat in a fetus is nothing unusual. As the heart continues to develop, these irregularities usually resolve themselves.
The development of the lungs is important for breathing. These are not yet fully developed and the child cannot yet breathe independently.
Size: XX
Seat height: 23 cm
BPD: 65mm
Weight: 913g
3. trimest
2. SSW (WEEK OF PREGNANCY)
Your baby's eyes are opening now. The retina forms different light-sensitive layers. This information is then sent to the brain.
To avoid contracting diseases during its first weeks of life, the baby arms itself via the placenta with antibodies from the mother's blood. After birth, these remain in his blood for a while. If you breastfeed your child, it will continue to absorb antibodies in this way.
Size: XX
Seat height: 24cm
BPD: 68mm
Weight: 1055g
28. SSW (WEEK OF PREGNANCY)
The baby now weighs about one-third of the estimated birth weight. The feet are now almost 5.5 cm long. Head hair is now relatively long. Milk teeth have formed under the gums.
If the baby is born now, it has a 90% chance of surviving as a premature baby.
Height: 35cm
Seat height: 25cm
BPD: 71mm
Weight: 1210g
29. SSW (WEEK OF PREGNANCY)
The baby has less and less space in the uterus and therefore does not move excessively. It is now learning to coordinate its movements and complete its nervous system. Until now, the brain surface was smooth; only now are the typical notches and shafts forming. The mass of the brain tissue is also increasing now.
Height: XX
Seat height: 26m
BPD: 73mm
Weight: 1379g
30. SSW (WEEK OF PREGNANCY)
The baby can now taste and feel pain. The feet are almost six centimeters long.
The wrinkled skin is considerably smoothed out. In boys, the testicles have moved to the groin. The child is now able to control its own body temperature.
Size: XX
Seat height: 27cm
BPD: 76mm
Weight: 1751g
31. SSW (WEEK OF PREGNANCY)
The eyes are now fully open and the child can distinguish light from dark.
Size: XX
Seat height: 28cm
BPD: 78mm
Weight: 1757g
32. SSW (WEEK OF PREGNANCY)
The fatty tissue under the skin becomes thicker. The toenails grow. In boys, the testicles move from the groin to the scrotum.
Examination: The development of the pregnancy is checked with the help of an ultrasound examination. In high-risk pregnancies, blood flow to the fetal brain, umbilical cord and placenta is measured (using Doppler ultrasound).
Size: 40 cm
Seat height: 30cm
BPD: 81mm
Weight: 1953g
34. SSW (WEEK OF PREGNANCY)
From this body weight, it would theoretically be possible for the child to survive without major complications if it were to be born prematurely. Children born at an even earlier time also have a good chance of survival due to modern technology.
The fingernails are now fully developed.
36. SSW (WEEK OF PREGNANCY)
The baby's body now becomes plump. The mother can now perceive the contraction of the uterus, the so-called prenatal contractions, which serve to practice breathing techniques.
Size: 45cm
Seat height: 33cm
BPD: 89mm
Weight: 2813g
37. SSW (WEEK OF PREGNANCY)
There is now a risk that the membrane will rupture and the amniotic fluid will drain. The hospital should be visited at this time at the latest.
From the 37th week, the position of the fetus will hardly change.
Size: XX
Seat height: 34cm
BPD: 91mm
Weight: 3028g
38. SSW (WEEK OF PREGNANCY)
The development of body fat continues. The downy hair that covered the body almost throughout pregnancy disappears. The wrinkles in the skin are smoothed out.
The child now gradually assumes the final birth position. Most children lie head down. About three to four percent are nevertheless born in the breech position, i.e., legs first. Only one in seven children is born by cesarean section on average.The expected birth position is clearly visible in the ultrasound image. A CTG can be obtained to check heart sounds in relation to contractions.
Size: XX
Seat height: 35cm
BPD: 92mm
Weight: 3236g
40. SSW (WEEK OF PREGNANCY)
Now the time of birth has come. The umbilical cord is 50 cm long. Labor can begin at any time.
During this examination, among other things, care is taken to ensure that there is still enough amniotic fluid and that the placenta has not stored too much calcium. Based on this examination, it is decided how long to wait before the birth must be induced.
Size: 50cm
Seat height: 37cm
BPD: 94mm
Weight: 3619g
Contact
GYNÉ LANG
Kohlrainstrasse 10
8700 Küsnacht (Zurich)
Phone +41 44 912 25 25
praxis@gynelang.ch
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