Every woman expecting offspring worries about whether her pregnancy is developing correctly. To ensure full control, it is recommended to visit the gynecologist in a timely manner. He will be able to correctly determine the size of the fetus according to the weeks of pregnancy, as well as identify certain deviations. For accurate diagnosis, modern ultrasound methods are used that allow you to compare the obtained data with the norms of fetal development.
Why you need to know the size
For every expectant mother, doctors determine the size of the fetus according to the weeks of pregnancy, as well as its weight. What is it for? The doctor can notice deviations in time and take measures, and the date of birth will be set more accurately. If these indicators are monitored regularly, it is easy to recognize a dead pregnancy, which can threaten a woman’s health.
The weight of the child at different stages of development also indicates how the birth will take place. If the fruit is too large, then a caesarean section may be required. If the baby is too small, it may happen that he will need first aid immediately after birth.
Fetal size by weeks of pregnancy by ultrasound
Measurements of the size of the fetus using ultrasound are called fetometry. It is carried out in two ways:
- A special small sensor is inserted into the vagina (vaginal method).
- The sensor is driven along the surface of the abdomen (abdominal method).
In the first trimester of pregnancy, the following are considered the main indicators of size:
- Fetal Egg. The size of the cavity in which the embryo develops is measured.
- Biparietal distance. The gap between the right and left temporal bone.
- Coccyx-parietal size. This is the distance from the tailbone to the top of the head.
On 2-3 trimester of indicators it becomes more, it:
- Fetal growth.
- The length of the hip bone.
- Biparietal head size.
- Chest (diameter).
- Circumference and girth of the abdomen.
- The length of the humerus.
- The distance between the forehead and the back of the head.
Deviations from the norm
All babies can develop in different ways, with jumps in periods. Doctors are guided by averaged indicators. So, the size of the fetus at 6 weeks of gestation (photo shown) in one mother may be slightly larger, in the other - slightly less. It also depends on the genetics of the parents. Over the entire development period, size measurement is carried out several times. Pathology is considered the case if several indicators at once differ much from the average norm.
Weight gain or decrease
What is the size of the fetus by week of pregnancy? In the ultrasound photo, this is clearly visible. If the fruit is too small, it is worth paying attention to the parents themselves, perhaps they both have a small complexion. Another reason may indicate bad habits of the mother (smoking, drinking); on the use of antibiotics. The fetus can grow slowly due to poor oxygen supply. In this case, the mother is advised to immediately give up alcohol and smoking, start to fully eat and stop taking antibiotics. Too fast weight gain in the fetus may indicate that the woman is abusing fatty foods. Sometimes the cause of a lot of weight is diabetes, which affects mom.
Decrease or increase in CTE (denotes the coccyx-parietal size)
When measuring the size of the fetus by weeks of pregnancy, the KTR indicator is used. It is important until 13 weeks. The fast-growing numbers of KTP indicate the factor that the fetus will grow very large in the future (4 or more kg). The doctor in this case does not recommend multivitamin complexes that accelerate metabolism. With a low KTR, there are suspicions of the following deviations:
- Hormonal insufficiency (appointment of "Duphaston" and "Utrozhestan").
- Suspicion of infection (an additional study is prescribed, and then treatment).
- In the development of the fetus, genetic disorders (for example, Down syndrome, etc.).
- Diseases of the internal organs of a woman (examination is prescribed).
- Fetal death (urgent surgery to remove the embryo).
Decrease or increase in BDP (means biparietal head size)
If the BDP is too low, this may indicate that there is a delay in development. It is likely that after birth, the baby will have various congenital malformations. Overestimated BDP indicators indicate the possibility of dropsy or hydrocephalus. In this case, the fetus may die if fluid accumulates in the brain cavity.
Sizes by weeks of pregnancy (1-10 week)
Week 1. This reference point has several concepts. If we talk about obstetric week, then the first day of menstruation, which was last recorded, is taken into account, and after that the woman had unprotected sex. If you count the moment of conception by day, you get the third obstetric week. When you consider the date of the delay of menstruation, you can get the fifth week. In gynecology, following the development of pregnancy, they rely on obstetric periods. The first week is not characterized by any special signs. This time is considered the beginning of the menstrual cycle. In this case, the level of hCG at this point is normal.
2 week. The obstetric week is characterized by the maturation of the zygote, with favorable contact, it will develop into pregnancy. A fertilized egg will attach to the uterine wall. Evidence of this may be discharge similar to egg white. Small impurities of the blood may appear due to the attachment of the egg. This is the norm.
3 week. At this time, we can say for sure that the conception has happened. The dimensions of the fetus are too small: 0.15-0.20 mm long and weighing 2-3 micrograms. If fertilization is unsuccessful, if the egg is not attached, menstruation may occur a little earlier than the calendar.
4 week. Embryo development is too active. A woman feels the first signs, changes in the body. The mammary glands begin to swell, the nipples are too sensitive. Menstruation delay. Scanty bloody discharge may be observed. During this period, there are great risks of anomalies in the development of the fetus, if a woman has increased physical activity, there are infections, fever, she abuse alcohol. The level of hCG in the blood rises. Ultrasound determines the corpus luteum, which nourishes the embryo and is involved in the active production of progesterone (pregnancy hormone). The fruit already has a length of 5 mm.
5 week. The length of the fetus is now 4-7 mm, and its weight is 3.5 g. The formation of primordia of the extremities, auricles, eyes, crevices of the mouth and nose, and some glands begins. The size of the uterus varies. At this time, it is already visible on an ultrasound scan - a single or multiple pregnancy develops. Set KTR, the size of the fetal bladder, the growth of the fetus.
6 week of pregnancy. The size of the fetus becomes larger, its length is 4-9 mm, while the weight is about 4.5 g. The mother feels changes in the body. The uterus grows to the size of a plum. At the 6th week of pregnancy, the size of the fetus, as well as the number of fetal bags, is clearly visible on an ultrasound scan. Small tubercles are noticeable, limbs will form in these places. On special devices you can already listen to the heartbeat.
7 week of pregnancy. The size of the fetus already has a length of 13 mm. The heart is divided into four chambers, the formation of blood vessels. Internal systems and organs are developing. The embryo begins to straighten up a little. The brain is actively developing. The umbilical cord is already fully formed.
8 week. The length of the fetus is already 14-22 mm. Slowly, he begins to move. The face begins to take on a human shape. The laying of systems and organs ends, many are already beginning to function. Genesis of the genitals and optic nerves occurs.
9th week. Growth is 22-30 mm, with a fetal weight of 2 g. The cerebellum, middle layer of the adrenal glands, pituitary gland, genitals, lymph nodes are formed. The limbs begin to move, muscles form. The ability to urinate appeared.
10 week. The first critical stage of development is coming to an end. The baby's weight of 5 g with growth reaches 40 mm. Heartbeat 150 beats / min. You can consider the fingers and joints of the limbs. The organs of the digestive tract are completing their formation. The foundations of the teeth are laid. At this time, the use of calcium is especially important for mothers.
11-20 weeks of development
11 weeks of pregnancy. The size of the fetus is already 5 cm in length and 8 g in weight. The embryo at this time can already be called a fetus. Blood vessels are formed, and the heart works fully. The first movements are observed in the intestine, similar to those of peristalsis. The genitals of the fetus continue to develop. Smell appears, eye color. Fingers and palms acquire the ability to feel.
12 week of pregnancy. The size of the fetus is already within 6-8 cm. Nails form on the fingers. Gastrointestinal tract completes the formation. The immune system is developing. At the 12th week of pregnancy, the size of the fetus becomes larger, the uterus increases. Mom feels her tummy begin to grow.
13 week. Beginning of the second trimester of pregnancy. The growth of the fetus is 8 cm with a weight of 15-25 g. Milk teeth are laid, the formation of muscle and bone tissue, digestive system, genitals continues.
14th week of pregnancy. The size of the fetus already in some cases reaches 10 cm, while its weight is 40 g. A skeleton and ribs are formed. The main organs and systems are already fully formed. The baby already has a blood type and its Rh factor.
15 week of pregnancy. The size of the fetus reaches 10 cm with a weight of 70 g. The cerebral cortex is formed. The endocrine system, sweat and sebaceous glands are activated. Formed taste receptors, respiratory movements. In the uterine cavity, the baby moves freely.
16 week. During this period, the growth of the fetus is 11 cm, while the weight is 120 g. The head rotates freely. Ears and eyes go up. The liver begins to work. Formed blood composition.
17 week. The immune system begins to work. The kid can already to some extent protect himself from infections that threaten his mother’s body. A fatty layer is formed. Height is 13 cm and weighs 140 g. The child begins to feel emotions, hear sounds from the outside. During this period, it is extremely important to establish contact with the baby.
18 week. The middle of the second trimester. The limbs are fully formed, fingerprints already exist. The rudiments of molars appear. Further development of the immune system, brain and adipose tissue occurs. Hearing is amplified; there is already a reaction to light. Fruit weight 200 g, height - 14 cm.
19 week. A strong leap in development. The movements are more perfect. The kid is already free to rotate or hold in any position. Original lubrication appears. Height - 15 cm, weight 250 g.
20 weeks of pregnancy. The size of the fetus at this time is 25 cm, and the weight is 340 g. The baby is fully formed. You can already hear the heartbeat with a stethoscope. Mom begins to acutely feel the fetal movements.
21-30 weeks of development
21 weeks of pregnancy. The size of the fetus, with a height of 27 cm, has a weight of 360 g. There is still enough space for active movement in the uterus. The fetus begins to swallow the amniotic fluid. Muscle and bone tissue is already strengthened. The spleen begins to work.
22 week. There is a significant increase in weight - up to 500 g. Growth also reaches 28 cm. Even in the case of the birth, the fetus can already be viable. The spine and brain are already fully formed. The heart is growing. Reflexes are improving.
23 week. The fetus is formed. The digestive system is functioning. Adipose tissue is growing. The genitals are clearly differentiated. The baby's weight is 500 g, height - 29 cm.
24 week. Weight 600 g, and height - 30 cm. Adipose tissue more and more. Growth hormone production begins. Sensory organs and reflexes are improved. There is already a pattern of sleep and wakefulness. The baby is sharply reacting to the emotions of the mother.
25 week. The kid has now grown to 34.5 cm, weight is 700 g. He is more and more like a newborn. Strongly developed sense of smell, emotions. Lungs prepare for spontaneous breathing. The vagina and testicles appear.
26 week. Individuality appears. The eyes open. The kid recognizes familiar voices. Bone tissue is strengthened. Lungs are formed. The production of various hormones occurs. The weight of the baby is 750 g, its length is 36.5 cm.
27th week. By this time, fetal growth is more active. Its weight already reaches 900 g. Metabolic processes in the body are developing. The endocrine system and the brain are actively working. Subcutaneous fat is getting bigger. Mom increasingly feels the baby’s movements.
28 week. At this period, the baby is already gaining his first 1 kg. Height is 38.5 cm. The space inside the uterus becomes much smaller, but this does not affect the development in any way.
29th week. The baby's body begins to prepare for the appearance of a white light. The work of the immune system, heat regulation is debugged. The blood composition is stable. The digestive system is ready. The skin becomes wrinkled, lighter. The gaze is already focused. Muscle tissue is strengthened.
30 week. The kid gained 1.5 kg. The nervous system is included in the work. Iron builds up in the liver. The eyes are often open. The fetus, as a rule, already occupies the position that should be during childbirth.
31-40 weeks of gestation
31 weeks. The baby weighs more than 1.5 kg. Surfactant production continues. The liver cleanses the blood. The connection between the brain and peripheral nerve cells has already been debugged. If the baby touches the cornea, then the eyes close. The development calendar is drawing to a close.
32 week. Active development continues. Systems and organs are fully operational. Appearance acquires the appearance of a baby. The fluff disappears. The skull remains soft, the baby occupies a prenatal position.
33 week. Weight normally reaches 2 kg. Muscle and subcutaneous fat build up. The kid can express emotions. The kidneys are getting ready for filtration.
34 week. Now the development of the fetus is almost complete. Gastrointestinal workouts are taking place. Individual facial features are increasingly distinct.
35 week. In this period, the organs have already developed. Basically, a set of muscle and fat is being maintained. Weekly growth is up to 220 g.
36 week. The body is improving. The work of vital systems is being debugged. The liver continues to accumulate iron. The baby is actively sucking a finger, so preparation for sucking the breast begins. Normal - head presentation of the fetus.
37 week. The fruit is finally formed. Intestinal motility is activated. Heat transfer processes are established. The lungs are ripe. There is a weekly increase in height and weight.
38 week. The kid is now ready to be born. The skin turns pink. In a male child, the testicles descend into the scrotum.
39 week. The organs and systems of the baby are ready for independent work. The response to light and sounds is well developed. The skin is no longer the original lubricant.
40 week. The approximate height of the newborn is 54 cm, while the weight is from 3 to 3.5 kg. The baby will be born soon, the formation of the fetus is complete.
It is important for every mom to know how a child develops inside her. This will allow you to correctly respond to changes in your own body and, if you need it right away, consult a gynecologist in time. Observations are important throughout the course of pregnancy.