Interesting Facts 

Determination of fetal body weight. Home methods of calculating weight. The value of the estimated fetal weight in the choice of obstetric tactics

The weight of the unborn child, still in the womb, worries expectant mothers and their doctors not out of idle curiosity - this indicator directly characterizes the degree of development of the fetus, the tactics of pregnancy and the upcoming delivery, allows you to foresee possible complications and minimize risks for both women and baby. That is why obstetricians and gynecologists necessarily determine the body weight of the unborn baby, guided by the basic arithmetic and automatic methods. In fact, there is nothing difficult in this - knowing the basic parameters and formulas required for calculations, you can easily make calculations yourself. How to do it? Read in our article!

Why should a pregnant woman and her doctor know the weight of the fetus

The body mass index is the best way to characterize the condition of the fetus. While the child is in the womb, it is necessary to monitor its development almost weekly - this will eliminate possible complications and, if necessary, take prompt measures to help the baby to be born healthy. It is enough to compare the figure obtained with the normal indicators calculated by the weeks of pregnancy - and it will immediately become clear how well the “interesting position” of the mother is proceeding. However, this reason is far from the only reason to know the weight of the child in advance:

  1. Determination of labor management tactics. It is imperative to calculate the weight of the baby in the womb in the last weeks of pregnancy in order to determine whether the patient can give birth on her own or if she will need additional medical care. If the estimated weight of the crumbs at 38-40 weeks exceeds 4 kg, most likely, the woman will be shown a cesarean section. However, everything also depends on the anatomical features of the woman in labor: there are often cases when women gave birth to larger babies without problems, but if the mother has a narrow pelvis, it will be difficult for her to give birth to even a small baby. Therefore, the diagnosis of "large fetus" is not a direct indication for cesarean - the decision remains with the attending physician and the woman in labor herself.
  1. Purchase of the first baby wardrobe. Some mothers think about buying a dowry for a child long before his birth, while others superstitiously postpone everything until the last moment. However, on the eve of the important hour, you just need to buy at least a couple of bodysuits, suits, T-shirts and, of course, a festive set for discharge. In order not to be mistaken with the size and not to get an outfit in which the baby, while in the womb, "gets lost" or, conversely, does not fit, it is better to be guided by at least the estimated calculated data.
  2. Psychological comfort of a pregnant woman. For the majority of parents, the coveted figures about the baby's weight are the guarantor of his normal health and well-being. Mom will be much calmer, knowing that everything is in order with the baby in the womb, he has enough nutrients for development, and therefore he is slowly growing and preparing to be born.

Ultrasound method for determining the weight of the child in the womb

Ultrasound examination is one of the most reliable ways to calculate the weight of the fetus. During pregnancy, the patient undergoes ultrasound screening at least 3 times, or even more, in which she can not only personally admire her child, but also find out the state of the uterus, placenta, internal organs of the child and, of course, its estimated weight.

However, only 3 times in 9 months for many especially impatient expectant mothers is unreasonably little! In such cases, you can not wait for the next study and, guided by the data obtained at the next gynecological examination, calculate the weight of the baby in the womb yourself.

Arithmetic formulas for calculations

Many online sites offer to use a special calculator that will give results based on the entered data, but it is much more interesting to figure out what the estimated indicators depend on. Let's look at the basic arithmetic formulas used by obstetricians-gynecologists.

  • Stroykova method

To determine the weight of the child in the womb, the following anthropometric indicators will be required:

  • patient weight (MB),
  • waist circumference of a pregnant woman (OJ),
  • the height of the standing of the uterine fundus (WDM).

In addition, in the table it is necessary to find a constant corresponding to the body weight of a pregnant woman:

For example, if the patient weighs 71 kg, the constant for calculations is 20. The last gynecological examination showed that the abdominal girth is 90 cm, and the height of the uterine fundus is 33 cm. This means that the weight of the child in the womb is (71: 20 + 90 * 33 ) / 2 = 1486.7 grams.

Studies have shown that Stroykova's formula allows you to get fairly accurate results, which turned out to be reliable in more than 50% of cases. At the same time, the probability of an error over 1 kg was only 1.5%, which is a very good indicator for arithmetic calculations of the estimated weight of the fetus in the womb.

  • Rudakov's method

It is possible to calculate the estimated figures, guided by the data obtained by palpation of the child in the womb, or rather, its length and semicircle width. Multiplying the numbers obtained, you can get the volume index, which, together with the calendar period of pregnancy, will tell you not only the weight of the crumbs, but also how full-term it is.

Pregnancy period, weeks

Volume index

Estimated weight of the child, gr.

Norm

Small fruit

Large fruit

  • Yakubova's formula

To calculate the weight of a child in the womb according to Yakubova's method, it is necessary to first measure the volume of the mother's abdomen (OB) and the height of the uterine fundus (VDM). Calculations should be made according to the formula: X = (coolant + VDM) / 4 * 100.

For example, the patient's waist circumference is 88 cm, and the height of the uterine fundus is 30 cm. Then the estimated weight of the fetus is (88 + 30) / 4 * 100 = 2950 grams.

  • Lankowitz technique

In this case, the calculations will require the circumference of the abdomen, the height of the uterine fundus and the height of the expectant mother (in cm), as well as her weight (in kg). The formula looks like this: X = (coolant + VDM + R + B) / * 10.

For example, if the mother's height is 168 cm, the weight is 58 kg, the waist circumference is 86 cm, and the height of the uterine fundus is 31 cm, then the estimated weight of the child in the womb will be (86 + 31 + 168 + 58) * 10 = 3430 grams.

  • Johnson calculations

To calculate the mass of the crumbs using this technique, you only need to measure the height of the uterine bottom above the bosom - all other numbers are constant coefficients: X = (WDM-11) / * 155 (if the mother's weight is less than 90 kg) or X = (WDM-12) / * 155 (if the mother's weight is more than 90 kg).

For example, with a uterine fundus height of 31 cm and a patient's body weight of 74 kg, the weight of the child in the womb will be (31-11) * 155 = 3100 grams.

All these calculations allow us to only tentatively assume how large the baby will be born while still in the womb. It will be possible to assess their reliability only after the birth of the long-awaited crumbs.


These numbers cannot be accurate, everyone knows that children can be born both 2500 and 4500, and are only indicative.

The fetal weight norm is almost the same for all women in the early stages, but with an increase in pregnancy, the individual difference becomes more and more. However, before giving birth, everyone really wants to know for sure whether the child is large, how the childbirth will proceed depends on it.

Determination of fetal weight using external measurements

Obstetricians-gynecologists have special calculation formulas that allow you to estimate the size, weight and size of the fetus in late pregnancy. You can independently, using simple calculations, calculate the weight of the fetus at 32 weeks and later using them. They are very inaccurate, for this reason, do not rely too much on the result.

Basic Fetal Weight Formula:

Coolant x WDM
Multiply the abdominal circumference by the height of the fundus of the uterus (in centimeters). For example, the weight of a fetus at 33 weeks in a woman with an abdominal circumference of 86 cm and a standing height of the uterine fundus of 33 cm will be 2838 grams, +/- 200 grams, according to this formula. However, these calculations can be influenced by a lot, for example, physique, the amount of amniotic fluid, the position of the baby in the uterus.

To clarify the result, the weight of the fetus is calculated using two additional formulas:

Coolant + WDM x 100
The sum of the circumference of the abdomen and the height of the fundus of the uterus must be divided by 4 and multiplied by 100, in the previous example it turns out, (86 + 33) / 4 * 100 = 2950 grams.

The third formula takes into account the physique of a woman, the so-called Solovyov index, the circumference of the wrist, is used. If it is more than 16 cm, 12 cm is subtracted, if less than 16 cm, 11 cm is subtracted.

(WDM - 12 or 11) x 155
The height of the fundus of the uterus, from it you need to subtract the coefficient (11 or 12) and multiply by 155, we get the weight in the previous version of the calculation of 3255 or 3410 grams, depending on the Soloviev index.

All the results obtained by the three formulas must be added and divided by three. It is clear that the accuracy of such calculations leaves much to be desired.

Fetal weight by ultrasound

You can most accurately calculate the estimated weight of the fetus by ultrasound, measurements that are carried out using ultrasound allow you to calculate the weight with great accuracy, while at the same time you can find out the correspondence of individual parameters to the gestational age.

Ultrasound tables, which indicate the norm of fetal weight by weeks with ultrasound, are very voluminous, we have brought them into a service that will allow you to find out the weight of the child and his height, simply by entering data from the ultrasound examination protocol.

In order to get a result, you need, at least, to have this protocol on hand.

You will need:

Know your gestational age in weeks of BPD, this is the biparietal head size, you can also use the LHR, the frontal-occipital head size or the baby's head circumference (OH).
- Coolant - the circumference of the child's abdomen
- DLB, child's thigh length
- DHrK - the diameter of the child's chest

For the calculation, all fields must be filled in, if your protocol does not indicate the circumference of the abdomen or the diameter of the chest, instead of them you can substitute the diameter of the chest or the circumference of the abdomen, respectively.

Determination of fetal weight by ultrasound does not depend on the amount of amniotic fluid, the position of the fetus in the uterus, and even the number of fetuses. The calculation of the weight of the fetus by ultrasound is closest to the real weight of the child at birth.

How to interpret the results obtained? So, you calculated the weight of the fetus, or looked at the table, or found out using an ultrasound scan. And you see that it doesn't match what was expected.

The norm of fetal weight by week may not correspond to your calculations, both upward and downward, and the longer the gestation period, the greater this difference may be.

In the early stages of pregnancy, the approximate weight of the fetus may be less or more than the calculated one only in cases where you made a mistake with the gestational age. In the future, the weight gain of the fetus depends on heredity, the state of the placenta, and other factors. Before giving birth, the normal weight of the fetus varies widely, and 2500 and 4500 may be the norm.

What does the weight of the fetus depend on?

From heredity
- on the nature of the diet, health status and the presence of bad habits in the mother
- from the peculiarities of the course of this pregnancy
- on the number of fruits.

With twins, the lag in fetal weight begins at about 20 weeks, and this trend continues until delivery. The weight of twins at birth is always less than the norm by about 1-2 weeks, in relation to those indicators given by the table of fetal weight by week. Now you know how to determine the weight of the fetus during pregnancy, you can constantly use the fetal weight formula, or you can use our ultrasound fetal weight calculator.

Fetal weight calculator

1. A week 40)) (alert ("5
2. 400)) (alert ("5 mm.
3. DLB (thigh length) 400)) (alert ("4 mm.
4. 400)) (alert ("13 mm.
5. Coolant (abdominal diameter)

One of the most modern and most accurate methods for determining these parameters is the ultrasound method (ultrasound). So, we will consider one of the main areas of application of ultrasound - fetometry - determining the size of the fetus or its individual parts of the body through ultrasound.

Fetometry includes the measurement of such basic indicators as:

  • coccygeal-parietal size (the distance between two points - the occipital tubercle and the coccyx);
  • biparietal head size (the greatest distance between the two parietal tubercles of the fetal head); -
  • head circumference;
  • the circumference of the abdomen of the fetus;
  • femoral length - fetal bones.

The coccyx is the parietal size. This measurement can be taken between 7-13 weeks of gestation and is the main indicator in setting the term. This indicator is very important for comparison with the set period in the subsequent, later stages of pregnancy.

The biparietal head size is measured after 13 weeks of gestation. It increases from 2.4 cm at 13 weeks to 9.5 cm by the end of pregnancy. Fruits with the same weight may have different biparietal sizes. Determining the gestational age using this index should be performed at the earliest possible date.

Femur length. The size of the femur increases from 1.5 cm at 14 weeks to 7.8 cm by the end of pregnancy. This measurement must also be taken as early as possible.

Fetal abdominal circumference. One of the main measurement methods in later periods. It reflects more the size of the fetus and its weight than the gestational age.

All these measurements form a clear picture of the gestational age, but such an important indicator as the weight of the child is of no less interest to expectant mothers. It is worth mentioning the methods for determining the weight of the fetus and its effect on the outcome of childbirth.

One of the indisputable signs of pregnancy is an enlarged belly. Have you ever wondered why and how it grows? It would seem that the answer is obvious: the belly grows because a child grows in it, and this happens in all expectant mothers the same way, because any normal pregnancy lasts 9 months (40 weeks, 41-42 - prolonged pregnancy). In fact, everything is much more complicated, and the peculiarities of the growth of the belly of a future mother can tell a specialist a lot.

How does the belly grow during pregnancy? Due to the growth of the fetus, uterus and an increase in the amount of amniotic fluid - the habitat of the future baby. At the beginning of pregnancy, many mothers lament that their belly is not growing fast enough. By the end of the term, on the contrary, they complain that it is very difficult to "carry" the tummy. How does a growing and rounded tummy change while carrying a baby?

By the end of the 4th week, the uterus reaches the size of a hen's egg, by the 8th week it increases to the size of two billiard balls, and by the 12th week (the end of the first trimester of pregnancy) the "baby house" becomes the size of his dad's fist. By this time, the uterus reaches the pubic articulation. Then the bottom of the uterus begins to rise above the bosom, and only after that the belly begins to grow and becomes noticeable.? By the end of the fourth month, at the 16th week, the fundus of the uterus is in the middle of the distance between the bosom and the navel, by the 20th week it is 4 cm below the navel, and by the sixth month it rises to the level of the navel.

By the 30th week, the fundus of the uterus begins to approach the sternum, reaching it by the 36th week (9 obstetric months). This is the highest position of the uterus in the entire pregnancy. In this case, the abdominal circumference is about 90 cm, the navel is smoothed. Before giving birth, the baby's head drops slightly, is fixed at the entrance to the small pelvis, and the bottom of the uterus drops to the level of a 32-week pregnancy, but the abdominal circumference increases significantly. By the end of pregnancy, the abdominal circumference is on average 96–98 cm, the navel protrudes.

Why is the doctor so carefully monitors the increase in mom's tummy? The point is that this is the easiest way to control the growth and development of a future baby. From about 14-15 weeks of pregnancy, during visits to the antenatal clinic, the obstetrician-gynecologist determines the weight of the expectant mother, the height of the fundus of the uterus (distance in cm from the pubic joint to the top point of the fundus of the uterus), and measures the abdominal circumference at the level of the navel. These values ​​help to assess whether the pregnancy is going well, the growth of the fetus, and an approximate estimate of the weight of the child.?

Both of the methods for determining weight presented by us are the Jordania formula, which is sometimes called the "Fortuneteller's Method" by the people (since without visualizing the fetus, we can assume the weight of the baby). The estimated fetal weight is determined after 35–36 weeks of gestation.

Jordania's formula looks like this: fetal weight (g) = VVDM (cm) x abdominal circumference (cm) + _ 200g, where VVDM is the height of the uterine fundus in cm? As an example, we will give the data of a certain pregnant woman A. Card of a pregnant woman in the antenatal clinic No. 65980. The gestational age is 37 weeks. By measuring the VVDM and abdominal circumference using a centimeter tape, we obtained the data for the height of the uterine fundus, which is 34 cm, and the abdominal circumference is 92 cm.Thus, the weight of the child at this stage of pregnancy is (34 × 92) 3008g + (-) 200 BC

Also, the data of the VSDM and abdominal circumference are used in Yakubova's formula: (VSDM + coolant) x 100/4. In the case of our pregnant A., the estimated fetal weight is: (36 + 84) x 100/4 = 3000g

Also, do not forget about the "calendar method" - this is a method for determining the duration of pregnancy and the weight of the fetus by the size of the pregnant uterus. The method includes measuring such parameters as: the height of the fundus of the uterus with a centimeter tape (the measurement method is described above), the width of the anterior semicircle (180 degrees) of the uterus in its widest part (carried out lying on the back)

It is worth noting that a large belly during pregnancy does not mean at all that you will have a large baby. In order to find out exactly this question, the specialist must send you for an ultrasound examination (a study to determine the mass is carried out from the middle of the third trimester of pregnancy), so that having received all the above fetometric data, he could present a clearer picture with the estimated weight of the baby.

As already mentioned, the estimated weight of the baby also depends on the weight gain of the expectant mother during pregnancy, so if you tend to be overweight, try to control your weight during pregnancy: weigh yourself every week and monitor the weight gain. Until the 20th week of pregnancy, it is advisable to gain no more than 700 g per week, in the period from the 20th to the 30th week up to 400 g, and after the 30th week 300–350 g. With an average physique of the expectant mother, weight gain is approximately is 10-12 kg for the entire pregnancy.

It is necessary to adhere to at least 7 points of the diet to prevent pathological weight gain:

Eat more fresh vegetables and fruits. Make salads, add herbs to them and season with vegetable oil.

Limit yourself to fried foods. Switch to stews, boiled and baked dishes.

Limit salt (this is a great prevention of edema) and spices.

Save the buns for later. Buy rye bread or wholemeal flour.

Prepare fresh vegetable and fruit juices. Cook unsweetened compotes, squeeze juices, make cocktails.

Don't forget about fermented milk products. They improve the functioning of the intestines, enrich the body with calcium and protein.

This does not mean that you need to cross out the lifestyle that you led before pregnancy and scrupulously redraw your entire diet. Enjoy this amazing period in your life - pregnancy, but remember that eating well and living well during pregnancy will have a positive effect on childbirth.

The weight of the fetus is an important indicator of its development. This criterion is included in the list of diagnostic parameters, on the basis of which the doctor makes a conclusion about the course of pregnancy, the presence or absence of abnormalities and prescribes appropriate examinations. The development of the baby is fast enough. This is facilitated by an increase in the uterus, the size of which increases 500 times during the gestation period. The weight of this organ at the last stage of pregnancy reaches 1 kg 200 g, while its initial weight is 50 g.

The baby's weight is monitored using ultrasound. This diagnosis is carried out from the middle of the first trimester. To carry out this procedure at an earlier date does not allow the size of the embryo, which is still too small to be noticed even by an ultrasound machine. At different stages of pregnancy, the fetus gains up to several hundred grams. Let's take a closer look at this process:

  1. On the 14th day of the cycle, the mature egg moves from the ovary to the fallopian tube. For the next 24 hours, she retains the ability to fertilize. If during this time period contact with the sperm occurs, the egg will be fertilized. Further, division will begin and on the fourth day it will move into the uterine cavity.
  2. After 3 weeks, the egg is implanted, this moment is considered the onset of conception. There are villi on the outer cells of the embryo, with which it attaches to the woman's blood vessels. This is how the placenta is formed. Tissues and organs will subsequently be formed from the internal cells. The embryo length at this stage is 6 mm. It is located in a bubble that is filled with liquid.
  3. From 5 to 6 weeks, the formation of the spine, nervous system and brain takes place. The development of the digestive system, mouth, chest begins. By the end of the 6th week, the heart begins to work, in which 4 departments function. In the head area, 4 depressions are formed, which will subsequently turn into ears and eyes. The circulatory system is laid. The embryo has 4 formations, from which the limbs will form.
  4. With the onset of 7 weeks, the length of the unborn baby reaches 13 mm. He has already formed a head, but so far it has parameters disproportionately large in relation to the body. You can see the face. Fingers begin to appear on the limbs. At this stage, cells are formed from which the skeleton will develop. The central nervous system is fully formed. There are internal organs, but their development is not yet complete.
  5. With the arrival of 8 weeks, the length of the fetus is 2.5 cm. The main organs have already completed their formation. The outlines of the mouth and nose are noticeable on the face, the tongue is formed. The arms and legs have increased in size. The toes are fairly well marked, but there are still membranes between them.
  6. At 12 weeks, the fetus increases to 65 mm, its weight is 18 g. On the head, you can see the auricles. The baby now has eyelids, thanks to which he can close his eyes. Marigolds are visible on the fingers. Muscle tissue develops, the child begins to actively move.
  7. From the 14th week, the placenta begins to perform one of its tasks and provides the fetus with nutrition. The head is still disproportionately large. The neck is different. The body is covered with lanugo fluff. The kid has eyebrows and eyelashes. His bones become harder, joints of his limbs have formed. The degree of development of the genitals allows you to determine the sex. The child acquires the skill of thumb sucking.
  8. By week 16, the organs and systems of the fetus are formed. It reaches 16 cm in length and 135 g in weight.
  9. At the gestation period of 20 weeks, the weight of the fetus is 340 g, the length is 25 cm. The baby has hairs and bases of the teeth. Organs that have already formed increase in size. The activity of the kidneys begins. The limbs acquire proportional dimensions to the body. The child is quite mobile. At this stage, mom feels it well.
  10. In the period from 21 to 24 weeks, the baby weighs 570 g, its length is 33 cm. He acquires new skills and already knows how to squint, frown, hiccup, cough, push, roll over, clench his fists. Sweat glands appear in the skin. The fetus has sufficiently developed auditory receptors. He is able to distinguish sounds, among which he distinguishes his mother's voice and heartbeat. The child spends a certain part of the time in a state of sleep. His tongue is already capable of discerning tastes.
  11. Until the 28th week, the baby gains 1 kg, his height reaches 37 cm. The formation of adipose tissue begins. The development of the cerebral cortex was completed. The lungs continue to form. The child is able to react to external stimuli and even cry.
  12. When it is 30 weeks of pregnancy, the weight of the fetus is about 1.5 kg, the height is 40 cm. At this stage, it prepares for appearance and takes a suitable position.
  13. By the 36th week, the child is gaining 2.5 kg and grows up to 46 cm. Thanks to the adipose tissue, he acquires a rounded shape. The skin color turns pink. The kid has acquired a grasping reflex, is able to raise his head and turn. The formation of the lungs is over. The child has a reaction to light.
  14. By the 40th week, the weight of the child is 3.4-3.5 kg, the height is 50-51 cm. The original lubricant spreads throughout the body. The head descends into the pelvic region. It should be noted that these parameters are relative. Each pregnancy must be considered on a case-by-case basis.

What determines the weight and growth of the fetus by weeks of pregnancy

Several factors influence the weight of the fetus. One of them is the mother's health status and her diet. Full growth of the baby is possible only with the optimal concentration of insulin. This substance promotes the formation of fatty layers, as well as all cells and tissues. With an excessive content of this element in the mother's body, the child is born with a large mass. This mainly applies to women with diabetes.

Anemia during gestation becomes the cause of placental insufficiency. This can lead to delayed development and the birth of an underweight baby. At 34 weeks of gestation, the weight of the fetus should normally reach 2150 g. If the baby weighs less, the doctor may suspect developmental anomalies. But in order to confirm or deny this, it is necessary to conduct a certain survey.

The size of the fetus also depends on the state of the placenta. Its growth is influenced by the uteroplacental blood flow. If the function of this organ is impaired, the fetus is not provided with sufficient nutrients and oxygen. As a result, the process of gaining mass and growth slows down.
Violations in the condition of the placenta or in the health of the expectant mother do not always adversely affect the weight of the child's body. With adequate therapy, the fetus develops according to established norms. If the baby's weight is less than the required indicator, but at the same time he does not have any abnormalities, treatment is not prescribed.

One of the factors affecting growth is heredity. The term "constitutional low birth weight" is used for such children. If the parents have a thin physique and short stature (up to 160 cm), the baby's low weight is physiological. Such a child has no pathologies.
But if the lack of weight is due to any violation, the woman should be under the close supervision of specialists. With placental insufficiency, developmental delay (malnutrition) is observed. There are two types of this state:

  • symmetrical;
  • asymmetric hypotrophy.

In the first case, all organs lag behind in development, in the second, certain organs correspond to the period, while others lag behind in development.

The weight of the child is also influenced by such factors as: heredity, the woman's lifestyle, the number of fetuses, various characteristics of gestation and the age of the mother. Women under 18 and over 35 require special supervision. They are most often diagnosed with child malnutrition. When 36 weeks of pregnancy is suitable, the fetus weighs 2.5 kg, the height is 45-46 cm.If the baby appears with these parameters earlier than a certain period, he is considered full-term and fully ready for life outside the mother's womb.
If the placenta does not fulfill its function, the expectant mother is prescribed vasodilating medications, the action of which is aimed at normalizing the blood supply to the vessels of the fetus and uterus. And also drugs are used that increase the child's resistance to oxygen deficiency.

Excess weight

Exceeding the norm also does not always indicate the presence of anomalies. The excessive weight of the baby, which is 4 kg or more, can be explained by the large physique of the parents or the excessive nutrition of the mother. If a woman is diagnosed with diabetes mellitus or other deviations of the endocrine system, a large mass of the child should be considered as a complication. This situation can also arise as a result of overburdening. If at 35 weeks of gestation, the weight of the fetus exceeds 2390 g, it can be argued that the baby will appear large.
The large weight of the baby complicates the delivery process. If his head is larger than the woman's pelvis, the doctor may decide to have a caesarean section. Too large sizes cause premature rupture of amniotic fluid and weak labor.

Home methods of calculating weight

You can determine the weight of the baby yourself at home. There are several options for this:

  1. One of them involves multiplying the abdominal circumference by the height of the uterine fundus. It must be borne in mind that the result can be influenced by the amount of amniotic fluid, the position of the fetus in the uterine cavity, and its physique. But, despite this, this method is considered to be the most reliable.
  2. According to the following method, you need to divide the abdominal circumference by the height of the uterine fundus. The result obtained should be divided by 4 more and multiplied by 100. This option is mainly not used as an independent calculation method, but is used to confirm the available indicators.
  3. You can also determine the weight of the fetus using the Soloviev method. Its peculiarity is that the size of the mother's wrist and her physique are taken into account. This method may seem unreliable; the ability to calculate the weight of a child by the wrist is questionable for some women. But at the same time, he gives true results.

The first step is to determine the index. If the wrist of the expectant mother has a circumference exceeding 16 cm, the index will be 12. With a circumference of less than 16 cm, this indicator will be 11. Further, the index is subtracted from the height of the uterine fundus, the resulting number is multiplied by 155. At 31 weeks of gestation, the weight of the fetus should reach 1.5 kg. To check how much the weight of the baby corresponds to this parameter, the measurement method according to Soloviev will help. To obtain the most reliable results, it is recommended to determine the weight using all three methods.

Determination of weight by ultrasound

In a medical institution, the weight of the fetus is determined by ultrasound diagnostics. The doctor focuses on the following indicators:

  • gestational age;
  • biparietal parameters of the head (the space between the two widest areas);
  • length of arms and legs;
  • frontal-occipital parameters;
  • circumference of the abdomen and head.

If abnormalities are found, a Doppler study of the child's vessels, placenta and umbilical cord is prescribed to clarify the diagnosis, which allows you to get an idea of ​​the blood flow velocity. It is also necessary to carry out cardiotocography.

Based on the results of this study, the doctor monitors the fetal heartbeat in response to uterine contractions. For example, the weight of the fetus at 33 weeks of gestation should reach 1900. If there is a lag behind this norm, this is an indication for additional research.

Fetal weight by week of pregnancy: table

Conclusion

Tracking fetal weight is one of the main gestation procedures. Based on the parameters of the baby, one can judge his development. And also timely detect deviations, if any. But do not immediately worry if the doctor says that the child is underweight or, on the contrary, exceeds the norm. Such phenomena can occur as a result of heredity or the characteristics of the course of pregnancy. Each case should be considered individually. And if violations in the development of the child are found, the use of medications will help to normalize the condition and a healthy baby will appear at the appointed time.
Video: fetal development by week

Fetal weight by weeks of pregnancy is a very important diagnostic indicator, which is assessed using ultrasound. Lack or excess weight indicates the development of a pathological process.

Normal intrauterine development is determined by many indicators. One of these parameters is the weight of the child. The weight of the fetus by weeks of pregnancy with deviations up or down indicates insufficient nutrition or the formation of hypoxia.

What determines the weight of the fetus during pregnancy?

The baby's weight depends on the functioning of the placenta and the supplied nutrients with oxygen. Starting from the second trimester, the fetus grows to 80 grams. At a later date, the seven-day intake reaches 200 grams, but before labor, the pace slows down significantly, due to the withering away of the placenta.

The indicator also depends on the following factors:

  • unbalanced nutrition of the mother;
  • stressful situations during gestation;
  • chronic diseases;
  • toxicosis;
  • smoking and alcohol abuse;
  • genetic predisposition.
The weight of the baby, during intrauterine development, also depends on gender. Boys are born larger than girls.

Fetal weight norm by week of pregnancy

In the first seven days after conception, the fertilized egg begins to divide, forming the placenta and fetus. Until 7 weeks, all vital organs are laid and formed. Outlines of a person appear - legs, arms, head, heart muscle. Already at the 5th week, the baby can be measured.

From the second trimester, the intensive growth of the baby begins. The rate of increase is about 80 g / week. Further, the weight of the fetus grows even more rapidly, reaching up to 300 g / week. During a 9-month period of intrauterine development, the uterus increases 500 times.

Doctors, when assessing the parameters for ultrasound, are guided by the general indicators of dimensions and circumferences. The main component is the positive dynamics of the intrauterine formation of the baby and its full development.

The approximate weight of a baby at 30 weeks is up to 1.4 kg. Any insignificant deviation can be perceived as a pathology or a normal condition, depending on the individual parameters of the expectant mother and the baby himself. By the beginning of labor, the baby reaches at least 3 kg 100 gr.

Fetal weight table by week of pregnancy

The estimated weight of the early fetus is calculated using ultrasound. At a later stage, the doctor, thanks to measurements of the abdominal circumference and the height of the standing of the uterus, can calculate this indicator.

The norms for the weight of the child by weeks of pregnancy are calculated, presented in the table:

Weeks Length,cm Weight, gr
11 week 4,1 7
12 week 5,4 14
13 week 7,4 23
14 week 8,7 43
15 week 10,1 70
16 week 11,5 100
17 week 13 140
18 week 14,2 190
19 week 15,3 240
20 week 25,8 300
21 week 26,7 360
22 week 27,8 430
23 week 28,9 500
24 week 30 600
25 week 34,6 670
26 week 35,6 760
27 week 36,6 875
28 week 37,6 1000
29 week 38,6 1150
30 week 39,9 1320
31 weeks 41,1 1500
32 week 42,4 1700
33 week 43,8 1900
34 week 45 2150
35 week 46,2 2380
36 week 47,4 2500
37 week 48,6 2800
38 week 49,8 3000
39 week 50,7 3300
40 week 51,2 3400

Calculate baby weight during pregnancy by weeks - calculator

The most informative method for calculating during pregnancy is ultrasound. The technician measures the length of the hip, the size and circumference of the head, and the diameter of the chest. After that, he gets the ratio, which is checked against the table of norms.

On examination, the doctor is able to calculate the baby's body weight using a special formula that takes into account the height of the bottom of the uterus, the circumference of the abdomen and the thickness of the woman's bone. The method is applied in the third trimester. In case of significant deviations, a specific diet and drug therapy is prescribed.

For the full development of the baby, both an overabundance and reduced indicators are equally dangerous. It is worth adhering to reasonable dietary norms and not neglecting walks in the fresh air, and a child's weight and height calculator during pregnancy will help to calculate the acceptable limits.