How to determine the estimated time. The exact definition of pr. Maternity leave rules
Pregnancy is one of the most exciting and at the same time crucial periods in the life of every woman, and therefore it is not at all surprising that each of us wants to know the date of birth as soon as possible. However, this issue often causes numerous disagreements and disputes. Expectant mothers “torture” doctors with their questions, because they want to prepare for an important event, but they only shrug, because they are not able to accurately determine the date of the birth of the long-awaited baby.
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Today: 29.05.2019
Date of the first day of the last menstruation:
Conception most likely happened (+-2 days):
Estimated due date:
Left before birth:
The calculation of the expected date of delivery (ED) is carried out in several ways, each of which is indicative. That is, if, according to estimates, the baby should be born on January 1, then it is not a fact that this will happen with absolute accuracy on that day. Very often there are deviations from the expected date in one direction or another. And childbirth can begin either 2 weeks earlier or later. I bring to your attention a fairly simple, but very effective way to find out the probable due date of a child, which has been successfully used by many doctors in clinics for quite a long time.
Calculation on the last day of menstruation
So to be on your own calculate gestational age and on it to determine the expected day of birth, it is necessary to remember the date of the beginning of the last menstruation. It is on its basis that all calculations are made. From this date, you must subtract 3 months and add another 7 days to the result. The resulting number will be the estimated date of birth of your long-awaited baby.For example, the date of the last menstruation is April 22. So, from this date you need to subtract 3 months. Subtract and receive - January 22. We add another 7 days to this figure and get January 29 - this day will be the expected date of birth.
It is worth noting that this method of calculation is best suited for women with a regular menstrual cycle that lasts 28 days.
4 Alternative Ways to Calculate Due Date
- 1. You can find out the due date, with a fairly high accuracy, by visiting the gynecologist's office. The doctor will not prescribe any tests for this, he will simply measure the size of the uterus, which will increase in size in accordance with the age of the fetus. However, this method of calculating the date of birth of the baby is effective only in the first trimester of pregnancy. In the later lines (in the 2nd and 3rd trimester), in each woman, an increase in the size of the uterus occurs with different intensity, depending on the individual characteristics of the organism.
- 2. You can calculate the date of birth by ovulation, which is the most favorable period in which conception is most likely to occur. On such days, a woman usually experiences an increased sexual desire. In addition, her secretions (cervical fluid) become more sticky and thick, basal body temperature rises by a few tenths of a degree, the cervix rises, and the mammary glands thicken and become painful.
In the same way, you can perform calculations on the date of conception. However, you should be aware that this period does not always coincide with the day on which sexual intercourse occurred. Fertilization of the egg, as a rule, occurs only on the third day.
- 3. Hardware calculation using ultrasonic waves can also be attributed to the most effective methods that allow you to determine the term of delivery with an accuracy of 1-3 days. The most correct calculations will be if ultrasound is done during the period of 11-14 weeks of pregnancy.
- 4. To declassify the secret of the date of birth of your child will help his first stirring, which usually occurs on the 20th week (in nulliparous) and on the 18th - in the second and subsequent pregnancies. In ancient times, when there was no ultrasound, this method of calculating the due date was almost the only one.
The effectiveness of hardware methods in calculating the term of labor
A study of the fetus in the third trimester on an ultrasound machine allows you to determine the date of pregnancy with high accuracy, and hence the expected date of birth. The fact is that only with the help of ultrasound diagnostics, the doctor can observe the condition of the placenta, the position of the baby's head in relation to the entrance to the small pelvis, the level of opening of the cervix, signs of fetal maturity, as well as many other important factors. All these parameters are decisive in determining the readiness of the future baby and his mother for childbirth.Deviation from the deadline - is it the norm?
As mentioned above, all calculations of the estimated date of birth are nothing more than an approximate guideline, which should not be heavily relied upon. According to statistics, only 17% of women give birth on the appointed day, while the remaining 83% - either earlier or later. Thus, we can conclude that no specialist, no matter how smart and qualified he may be, is able to predict with high accuracy the date of the onset of labor activity.Normally, childbirth can occur between 38 and 42 weeks. pregnancy. The birth of a child will not be premature or belated, but normal and physiological. Sometimes, for certain reasons, labor can begin prematurely. This happens due to deviations in the development of the fetus, stressful situations, various pathological processes occurring in the mother's body, hereditary factors, etc.
Often there is a re-carrying of pregnancy due to the fact that in the first trimester there were any complications. In addition, maternal heredity should be taken into account. If your mother and grandmother gave birth much later than the due date, then most likely the same thing awaits you. Therefore, it is very important to realize that the calculation of the term of childbirth is a very complex, conditional and individual issue for each expectant mother.
How do the features of the menstrual cycle affect the date of birth?
The length of a woman's menstrual cycle also affects the duration of childbirth. For example, if it exceeds the standard twenty-eight days, then most likely the pregnancy will last more than forty weeks, and vice versa. However, in this case, the deviation in one direction or another usually does not exceed 5 days. It is worth noting that errors are often made in such calculations, since very often ordinary bleeding is taken for menstruation, which opened after the fertilization of the egg. Table of contents of the subject "Determination of the term of childbirth and the estimated body weight of the fetus. Study of the blood flow of the fetus.":1. Physiological test with breath holding on inhalation and exhalation. Doppler study of blood flow in the mother-placenta-fetus system. Study of fetal blood flow.
2. Biophysical profile of the fetus. The concept of biophysical profile. Criteria for assessing the biophysical parameters of the fetus.
3. Motor activity of the fetus. Amnioscopy. Determination of the volume of amniotic fluid.
4. Determination of the term of delivery and the estimated body weight of the fetus.
6. Formulas for determining the duration of pregnancy. Jordanian formula. Skulsky formula.
7. Ultrasound scanning in determining the duration of pregnancy. Fetometry. Biparietal head size. Computer fetometry.
8. Determination of the estimated weight of the fetus. Fetal hypotrophy. Large fruit.
9. Determination of the estimated weight of the fetus according to the Jordani formula. Jordanian formula. Lankowitz formula. Johnson formula.
10. Determination of the estimated weight of the fetus according to Stroykova. Yakubova's formula. Rudakov's formula. Formula R. W. Johnson (Johnson) and S. E. Toshach (Toshach).
Estimated due date is set:
1) By date of last menstrual period; 280 days are added to the first day of the last menstruation and the date of the expected due date is obtained. In order to simplify the calculations, according to Negele's proposal, count from the first day of the last menstruation 3 months ago and add 7 days to the resulting number. For example, if the last menstruation began on November 15, then counting from it 3 months ago (August 15) and adding 7 days, we get the date of birth - August 22.
2) By ovulation; 14-16 days are counted back from the first day of the expected but not arrived menstruation and 273-274 days are added to the received date.
3) According to the time of fertilizing sexual intercourse; if the exact day of pregnancy is known, 273 days are added to it or counted back 3 months.
From the moment we realize the fact of pregnancy, the expected date of the birth of the child is of interest to us almost in the first place. At the same time, our interest is caused not only by curiosity and the desire to prepare for the appearance of the baby. An accurate determination of the EDD (estimated date of birth) will allow you to correctly set the time for maternity leave, control the gestational age of the child, and determine whether he is lagging behind in development. In addition, this information will allow you to adjust the moment of delivery, avoiding over-pregnancy or premature induction of labor.
Actually, we receive information about the date of the expected birth literally at the first visit to the gynecologist. And yet, more than 26% of women during pregnancy will repeatedly adjust the timing of the expected birth, focusing on the results of various tests. Given that any of the currently existing methods is not 100% accurate, the estimated time frame is determined by the combination of the results of various studies, each of which we will talk about today.
How long does pregnancy last
As a rule, nature has given a woman 40 weeks or 9 calendar or 10 lunar months to carry a pregnancy. It is believed that pregnancy lasts 280 days, starting from the first day of the last menstruation, or 263-273 days from the moment of conception, approximately 266 days or 9 and a half lunar months. However, it should be remembered that only 5% of women give birth according to the schedule, the remaining 95% give birth, as a rule, three weeks before or two after the expected date of birth. A difference of 14 days should not be a cause for concern.
Precise definition of DA - useful formulas
What methods can we use, being at a period of 15 - 17 weeks of pregnancy, in order not only to clarify the term, but also to calculate the date of the expected birth.
The most common is Nagel's rule recommended by the World Health Organization. According to him, it is necessary to subtract three months from the date of the first day of the last menstruation, focusing on the calendar, and then add seven days to the result. For example, if the last period began on February 1, minus 3 months would be November 1 and add seven days would be November 8, which would be the expected date of birth. An interesting fact, the calculation formulas will be most accurate if the intended child is a girl, in this case the error is 1.4 days, in the case of a boy, the error is three days or more.
Formulas for determining the term at the time of conception
Nagel's rule is effective in the case of a regular menstrual cycle, ideally 28 days. However, not all women can boast of such an ideal cycle, it can be extended to 32 days, or shortened to 21 days, moreover, for many women, the menstrual cycle is not at all regular with the exact number of days observed. In this case, we will be interested in the moment of conception, which is most likely at the time of ovulation.
It just seems that getting pregnant is easy, in fact, during the monthly cycle there is a small favorable corridor, the size of a week, during which a child can be conceived. This period falls at the time of ovulation or maturation of the egg, and given that the duration of its existence is not more than a day, and spermatozoa are stored after sex for no more than 5 days, you can calculate the estimated conception period, and by adding 266 days to it, determine the date of future birth. It should be remembered that ovulation, as a rule, occurs in the middle of the cycle, that is, if the cycle is 21 days, then the moment of ovulation can occur already on the 10th day after the first day of the last menstruation, if 32 is 18. Accordingly, the period is 5– 6 days before ovulation inclusive and is the most likely period of conception.
Ultrasound diagnostics
Ultrasound determines gestational age, focusing on the size of the fetal egg, measuring the distance from the head to the lowest point of the spine. On the basis of the results obtained, a conclusion is made, which gestational age corresponds to the gestational age of the child. At the same time, the most favorable period is, since after they talk about errors, taking into account the individual characteristics of the development of the child. For example, at 15–17 weeks, the error in determining the estimated period by ultrasound will be 7 days.
Nevertheless, there are many details that can confirm or refute the previously set deadlines. For example, when conducting a study, pay attention to the placenta, the degree of its maturation and thickness. At term, its thickness is equal to the number of weeks of pregnancy plus or minus 2 millimeters.
fetal movement
The least accurate method of determining the estimated due date, because it is very subjective. According to accepted standards, if a woman’s pregnancy is not the first, she begins to feel the baby’s movement at, primiparous at 20. However, given the acceleration of the younger generation, by 15–17 weeks, many, especially multiparous ones, can hear the first tremors of the child.
A few words in conclusion
The exact definition of the PDR (15-17 weeks) is calculated taking into account all the above methods, and even in this case there is no guarantee to give birth at the expected date, since many factors affect when the birth occurs, including the psychological background, the presence of stress, hormonal deviations or too busy work schedule. We can only wait, focusing on the estimated date, and not be upset if the child is delayed, say, for a week, with an excellent heartbeat, this is completely normal.
It is almost impossible to determine the exact date of birth in each specific case of pregnancy. It is presumably determined.
The onset of pregnancy may not coincide with the date of sexual intercourse, and even if pregnancy occurred after a single sexual intercourse, the exact date of fertilization remains unknown. This is due to many factors: the moment of ovulation, the viability of the egg after ovulation, the duration of the fertilizing ability of spermatozoa located in the female genital tract. Depending on the duration of the menstrual cycle, ovulation can occur between the 8th and 16th day of the cycle, therefore, the period of possible fertilization, taking into account the viability of the egg and sperm, can be from the 8th to the 18th day.
However, using anamnestic and objective data, with a sufficient degree of probability, the term of delivery in each pregnant woman is determined.
The expected due date is set as follows:
1) by the date of the last menstruation: 280 days are added to the first day of the last menstruation and the date of the expected due date is obtained; in order to quickly and easily establish this period, at the suggestion of Negele, 3 months are counted back from the first day of the last menstruation. and add 7 days;
2) according to the date of the first fetal movement: 20 weeks are added to the date of the first fetal movement in the primipara, and 22 weeks in the multiparous;
3) according to the gestational age diagnosed at the first visit to the antenatal clinic; the error will be minimal if the woman went to the doctor in the first 12 weeks. pregnancy;
4) according to ultrasound data;
5) by the date of going on prenatal leave, which starts from the 30th week of pregnancy. Add 10 weeks to this date.
For a quick and accurate calculation of the duration of pregnancy and childbirth by the date of the last menstruation and by the first movement of the fetus, special obstetric calendars are issued.
Thus, the term of the expected birth will be determined quite accurately if all the data received are not contradictory, but complement and reinforce each other. However, even in such a situation, errors are possible, because all calculations are carried out based on the duration of pregnancy, equal to 280 days, or 40 weeks. Obstetrical experience shows that urgent delivery can occur over a wider range of time (from 38 to 42 weeks), which increases the likelihood of errors in determining the date of delivery.
Rules for registration of maternity leave.
A disability certificate for pregnancy and childbirth is issued by a doctor of the antenatal clinic from 30 weeks of pregnancy at a time for a duration of 126 calendar days. Pregnant women living in the territories affected by the Chernobyl disaster are issued a certificate of incapacity for work for pregnancy and childbirth from 27 weeks of pregnancy for a duration of 146 calendar days.
In case of complicated childbirth, the birth of two or more children, the VKK of the antenatal clinic issues an additional certificate of incapacity for work for a period of 14 calendar days.
Physiological changes in a woman's body during pregnancy.
The emergence and development of pregnancy is associated with the formation of a new functional mother-fetus system. It has been established that changes in the mother's condition during pregnancy actively affect the development of the fetus. In turn, the condition of the fetus is not indifferent to the mother's body. At different periods of intrauterine development, numerous signals come from the fetus, which are perceived by the corresponding organs and systems of the mother's body and under the influence of which their activity changes. The main link between the organisms of the mother and fetus is the placenta.
During a physiologically proceeding pregnancy, in connection with the development of the fetus and placenta in the mother's body, significant changes in the function of all the most important organs and systems are observed. These changes are of a pronounced adaptive nature and are aimed at creating optimal conditions for the growth and development of the fetus.
Endocrine system. The onset and development of pregnancy are accompanied by endocrine changes in the mother's body. The complexity of the changes is determined by the fact that the hormones of the placenta, as well as the fetus, have a great influence on the activity of the endocrine glands of the mother.
Anterior pituitary gland increases during pregnancy by 2-3 times. Histological examination reveals large acidophilic cells, called "pregnancy cells", the appearance of which is due to the stimulating effect of sex steroid hormones of the placenta. Morphological changes in the anterior pituitary gland affect the function of this organ: a sharp inhibition of the production of follicle-stimulating (FSH) and luteinizing (LH) hormones and an increase (5-10 times) in the production of prolactin (Prl) during pregnancy, and an increase in FSH and LH along with a decrease Prl products. in the postpartum period.
During a physiologically proceeding pregnancy, the content of somatotropic hormone (GH) in the blood is practically not changed, only at the end of pregnancy there is a slight increase in it.
There are significant changes in the production of thyroid-stimulating hormone (TSH). Already soon after the onset of pregnancy in the blood of the mother, an increase in its content is noted. In the future, as pregnancy progresses, it increases significantly and reaches its maximum before childbirth.
During pregnancy, there is increased secretion of adrenocorticotropic hormone (ACTH), associated with hyperproduction of corticosteroids by the adrenal glands.
Posterior pituitary gland does not increase. Oxytocin produced in the hypothalamus is stored in the posterior pituitary gland. The synthesis of oxytocin especially increases at the end of pregnancy and in childbirth.
The onset and development of pregnancy is associated with the function of a new endocrine gland - corpus luteum of pregnancy. In the corpus luteum, sex hormones (progesterone and estrogens) are produced, which play a huge role in implantation and the further development of pregnancy. From the 3-4th month of pregnancy, the corpus luteum undergoes involution and its function is entirely taken over by the placenta. Stimulation of the corpus luteum is carried out by chorionic gonadotropin. The blockade of the secretion of FSH and LH of the adenohypophysis is accompanied by a natural inhibition of the maturation of follicles in the ovaries; ovulation also stops.
Thyroid. Most women experience an increase during pregnancy. This is due to its hyperplasia and active hyperemia. The number of follicles increases, the content of colloid in them increases. These morphological changes are reflected in the function of the thyroid gland: the blood concentrations of thyroxine (T4) and triiodothyronine (T3) associated with proteins increase.
Function parathyroid glands slightly reduced, which is accompanied by disorders of calcium metabolism. This, in turn, may be accompanied by the occurrence of convulsive phenomena in the calf and other muscles in some pregnant women.
Adrenals. Hyperplasia of the adrenal cortex and increased blood flow in them are observed. This is reflected in increased production of glucocorticoids and mineralocorticoids. Nervous system. This system of the mother plays a leading role in the perception of numerous impulses coming from the fetus. During pregnancy, the uterine receptors are the first to begin to respond to impulses from the growing fetal egg. The uterus contains a large number of various nerve receptors: sensory, chemo-, baro-, mechano-, osmoreceptors, etc. The impact on these receptors leads to a change in the activity of the central and autonomic (vegetative) nervous system of the mother, aimed at ensuring the correct development of the unborn child.
The function of the central nervous system undergoes significant changes. From the moment of pregnancy, an increasing flow of impulses begins to flow into the mother's central nervous system, which causes the appearance of a local focus of increased excitability in the cerebral cortex - gestational dominant, around which a field of inhibition of nervous processes is created. Clinically, this process manifests itself in a somewhat inhibited state of the pregnant woman, the predominance of her interests directly related to the birth and health of the unborn child. In the event of various stressful situations in the central nervous system, other foci of persistent excitations may also occur, which greatly weakens the effect of the gestational dominant and is often accompanied by a pathological course of pregnancy.
During pregnancy, the state of the central nervous system changes. Until the 3-4th month of pregnancy, the excitability of the cerebral cortex is generally reduced, and then gradually increases. The excitability of the underlying parts of the central nervous system and the reflex apparatus of the uterus is reduced, which ensures the relaxation of the uterus and the normal course of pregnancy. Before childbirth, the excitability of the spinal cord and the nervous elements of the uterus increases, which creates favorable conditions for the onset of labor.
The cardiovascular system. The cardiovascular system functions during pregnancy with an increased load due to increased metabolism, an increase in the mass of circulating blood, the development of the uteroplacental circulation, a progressive increase in the body weight of the pregnant woman, etc. As the size of the uterus increases, the mobility of the diaphragm is limited, intra-abdominal pressure increases, the position of the heart in the chest changes cell (it is located more horizontally), at the top of the heart in some women there is an unsharply pronounced functional systolic murmur.
Already in the first trimester of pregnancy, the BCC increases to a large extent and further increases all the time (by about 30-50%), reaching a maximum by the 36th week. Hypervolemia occurs mainly due to an increase in blood plasma volume with the occurrence of physiological anemia in pregnancy.
In the second trimester of pregnancy, there is a decrease in systolic and diastolic pressure by 5-15 mm Hg. Peripheral vascular resistance also decreases. This is due to the formation of the uterine circulation, which has low vascular resistance, as well as the effect on the vascular wall of estrogens and progesterone of the placenta.
During pregnancy, physiological tachycardia is observed. The heart rate reaches a maximum in the third trimester of pregnancy, when this figure is 15-20 per minute higher than before pregnancy.
The most significant hemodynamic shift during pregnancy is an increase in cardiac output (by 30-40%). Cardiac output begins to increase from the earliest stages of pregnancy, with its maximum change observed at 20-24 weeks. On the ECG, a deviation of the EOS can be detected, which reflects the displacement of the heart in this direction. On echocardiography, an increase in the mass of the myocardium and the size of individual parts of the heart is noted. An X-ray examination reveals changes in the contours of the heart, resembling a mitral configuration.
Respiratory system. With an increase in the size of the uterus, the abdominal organs gradually shift, the vertical size of the chest decreases, the excursion of the diaphragm is limited, as a result of which there is some increase in breathing (by 10%) and a gradual increase in the respiratory volume of the lungs by the end of pregnancy (by 30-40%) . As a result, the minute volume of breathing increases from 8 l / min at the beginning of pregnancy to 11 l / min at the end of it.
Digestive system. Many women in the early stages of pregnancy experience nausea, vomiting in the morning, taste sensations change, and intolerance to certain foods appears. As the gestational age increases, these phenomena gradually disappear.
Pregnancy has an inhibitory effect on the secretion of gastric juice and its acidity. All sections of the gastrointestinal tract are in a state of hypotension due to changes in topographic and anatomical relations in the abdominal cavity due to an increase in the pregnant uterus, as well as neurohormonal changes inherent in pregnancy (the effect of placental progesterone on the smooth muscles of the stomach and intestines). This explains the frequent complaints of pregnant women about constipation.
Liver function undergoes significant changes. There is a significant decrease in glycogen stores in this organ, which depends on the intensive transition of glucose from the mother's body to the fetus. The intensification of glycolysis processes is not accompanied by hyperglycemia, therefore, in healthy pregnant women, the nature of glycemic curves does not change significantly. The intensity of lipid metabolism changes. This is expressed by the development of lipemia, a higher content of cholesterol in the blood. The content of cholesterol esters in the blood also increases significantly, which indicates an increase in the synthetic function of the liver.
The protein-forming function of the liver changes, which is primarily aimed at providing the growing fetus with the necessary amount of amino acids, from which it synthesizes its own proteins. Starting from the second half of pregnancy, the concentration of total protein in the blood plasma begins to decrease slightly. Pronounced shifts are also observed in the protein fractions of the blood (a decrease in the concentration of albumin and an increase in the level of globulins).
Urinary system. During pregnancy, the mother's kidneys function with increased load, removing from her body not only the products of its metabolism, but also the products of the metabolism of the fetus.
The processes of blood supply to the kidneys undergo significant changes - an increase in it in the first trimester of pregnancy and a gradual decrease in the future. In parallel with changes in blood supply, glomerular filtration also changes, which increases significantly in the first trimester of pregnancy (by 30-50%), and then gradually decreases, while tubular reabsorption remains unchanged throughout pregnancy. This contributes to fluid retention in the body of a pregnant woman, which is manifested by pasty tissues on the lower extremities at the end of pregnancy. At the end of pregnancy, sodium is retained in the extracellular fluid, which increases its osmolarity.
Some women have orthostatic proteinuria. This is due to compression of the liver of the inferior vena cava and the uterus of the veins of the kidneys. Sometimes there is glucosuria - due to an increase in glomerular filtration.
During pregnancy, the topography of organs adjacent to the uterus changes. This primarily concerns the bladder and ureters. As the size of the uterus increases, compression of the bladder occurs. By the end of pregnancy, the base of the bladder moves upwards beyond the small pelvis. The walls of the bladder hypertrophy and are in a state of increased hyperemia. The ureters are hypertrophied and slightly elongated.
Hematopoietic organs. During pregnancy, the processes of hematopoiesis intensify. However, due to hypervolemia, by the end of pregnancy, there is a decrease in hemoglobin, red blood cell count and hematocrit. Activation during pregnancy of the erythropoietic function of the bone marrow is associated with increased production of the hormone erythropoietin, the formation of which is stimulated by placental lactogen.
During pregnancy, not only the number, but also the size and shape of red blood cells changes. The volume of erythrocytes increases especially noticeably in the II and III trimesters of pregnancy. The increased volume of erythrocytes increases their aggregation and changes the rheological properties of the blood as a whole. Starting from early pregnancy, an increase in blood viscosity is observed. The concentration of serum iron during pregnancy is reduced compared to that of non-pregnant women (at the end of pregnancy to 10.6 µmol/l). Activation of a white blood germ is observed (the number of leukocytes increases). There is an increase in ESR (up to 40-50 mm/h).
The immune system. During pregnancy, very complex immunological relationships arise and form between the organisms of the mother and the fetus, based on the principle of direct and feedback. These relationships ensure the correct, harmonious development of the fetus and prevent the rejection of the fetus as a kind of allograft. The most important factor in the protection of the fetus is the immunological tolerance of the maternal organism to the antigens of the fetus of paternal origin, due to various mechanisms.
hemostasis system. During pregnancy, there is a significant (up to 150-200%) increase in the content of all plasma factors (except XIII) of blood coagulation, a decrease in the activity of natural inhibitors of blood coagulation, inhibition of fibrinolysis activity and a slight increase in the adhesive-aggregation properties of platelets.
Metabolism. With the onset of pregnancy, significant changes occur in metabolism. Significant changes are observed in protein, carbohydrate and lipid metabolism.
As pregnancy progresses, the woman's body accumulates protein substances, which is necessary to meet the needs of the growing fetus in amino acids. Changes in carbohydrate metabolism are characterized by the accumulation of glycogen in the cells of the liver, muscle tissue, uterus and placenta. During the physiological course of pregnancy in the mother's blood, there is a slight increase in the concentration of neutral fat, cholesterol and lipids.
Mineral metabolism undergoes various changes: there is a retention of calcium and phosphorus salts.
During pregnancy, the need for vitamins increases significantly. Vitamins are necessary both for the physiological course of metabolic processes in the mother's body, and for the proper development of the fetus. Most vitamins cross the placenta to some extent and are used by the fetus during its growth and development.
Certain adaptive changes during a physiological pregnancy are observed in the acid-base state (ACS). It has been established that in pregnant women there is a state of physiological metabolic acidosis and respiratory alkalosis.
The musculoskeletal system. During the physiological course of pregnancy, pronounced changes occur in the entire musculoskeletal system of a woman. There is serous impregnation and loosening of the ligaments, cartilage and synovial membranes of the pubic and sacroiliac joints. As a result, there is some divergence of the pubic bones to the sides (by 0.5-0.6 cm).
The chest expands, the costal arches are located more horizontally, the lower end of the sternum somewhat moves away from the spine. All these changes leave an imprint on the entire posture of a pregnant woman.
Leather. In many pregnant women, brown pigment is deposited on the face, nipples, areola, due to changes in the function of the adrenal glands. As the gestational age increases, a gradual stretching of the anterior abdominal wall occurs. So-called pregnancy scars appear, which are formed as a result of the divergence of the connective tissue and elastic fibers of the skin. Pregnancy scars look like pink or blue-purple bands of an arched shape. Most often they are located on the skin of the abdomen, less often - on the skin of the mammary glands and thighs. After childbirth, these scars lose their pink color and take on the appearance of white stripes.
The navel in the second half of pregnancy is smoothed out, and later protrudes. In some cases, during pregnancy, hair growth is noted on the skin of the face, abdomen, and thighs, which is due to increased production of androgens by the adrenal glands and partly by the placenta.
Sexual system.Uterus increases in size throughout pregnancy, however, this increase is asymmetrical, which largely depends on the site of implantation. During the first few weeks of pregnancy, the uterus is pear-shaped. At the end of the 2nd month of pregnancy, the size of the uterus increases approximately 3 times and it has a rounded shape. During the second half of pregnancy, the uterus retains its rounded shape, and at the beginning of the third trimester it becomes ovoid. As the uterus grows, due to its mobility, some of its rotation occurs, more often to the right. At the end of pregnancy, the weight of the uterus reaches an average of 1000 g (50-100 g before pregnancy). The volume of the uterine cavity at the end of pregnancy increases by more than 500 times. The increase in the size of the uterus occurs due to the progressive processes of hypertrophy and hyperplasia of muscle elements.
The fallopian tubes thicken, blood circulation in them increases significantly. Their topography also changes (by the end of pregnancy, they hang down along the ribs of the uterus).
ovaries slightly increase in size, although the cyclic processes in them stop. During the first 4 months of pregnancy, a corpus luteum exists in one of the ovaries, which subsequently undergoes involution. Due to the increase in the size of the uterus, the topography of the ovaries, which are located outside the small pelvis, changes.
Ligaments of the uterus significantly thicken and elongate. This is especially true of the round and sacro-uterine ligaments.
Vagina. During pregnancy, hyperplasia and hypertrophy of the muscular and connective tissue elements of this organ occur. The blood supply to its walls increases, there is a pronounced serous impregnation of all its layers. As a result, the walls of the vagina become easily extensible. The mucous membrane of the vagina due to congestive venous plethora acquires a characteristic cyanotic color. The processes of transudation are intensifying, as a result of which the liquid part of the vaginal contents increases. In the protoplasm of the stratified squamous epithelium, a lot of glycogen is deposited, which creates optimal conditions for the reproduction of lactobacilli. The lactic acid secreted by these microorganisms maintains the acidic reaction of the vaginal contents, which is an important deterrent to ascending infection. The external genitalia loosen during pregnancy, the mucous membrane of the entrance to the vagina has a distinct cyanotic color. Sometimes varicose veins appear on the external genitalia.
Other internal organs. Along with the urinary system, significant changes in connection with pregnancy are also observed in the abdominal organs. The lean, ileal and caecum, appendix are displaced by the pregnant uterus up and to the right. At the end of pregnancy, the appendix can be located in the region of the right hypochondrium. The sigmoid colon is displaced upward and may be pressed against the upper edge of the pelvis at the end of pregnancy. At the same time, there is compression of the abdominal aorta, inferior vena cava, which can lead to varicose veins of the lower extremities and rectum.
Hygiene and nutrition of pregnant women.
PLAN
1. The size of the uterus and the height of its bottom at various stages of pregnancy.
2. Measurement of the fetus (length of the body, its head).
3. Formulas of Skulsky, Jordania, Lebedeva.
Determination of gestational age and date of birth
The determination of the gestational age is carried out on the basis of anamnestic data (delayed menstruation, date of the first movement of the fetus), according to an objective examination (the size of the uterus, the size of the fetus) and according to additional research methods (ultrasound).
The gestational age and date of birth is determined by:
- by date of last menstrual period. From the first day of the last menstruation count the number of days (weeks) at the time of examination of the pregnant woman. To determine the date of birth, 280 days (10 lunar months) are added to the first day of the last menstruation or the Negele formula is used: 3 months are subtracted from the date of the beginning of the last menstruation and 7 days are added. This method cannot be used in women with irregular menstrual cycles.
- by ovulation. If, due to certain circumstances, a woman can name the date of the intended fertilization (IVF, insemination with donor sperm), then the gestational age is counted from the date of conception, after adding 2 weeks, and the date of birth is determined by counting 38 weeks from the date of expected ovulation, or using the following formula: from ovulation dates take away 3 months 7 days.
- on the first turn. When registering for pregnancy, a mandatory moment in the study of a pregnant woman is a vaginal examination, in which the gestational age can be determined with a certain accuracy (see table).
- on the first stirring. Determining the gestational age by the date of the first movement of the fetus is possible in the second half. On average, primiparous women feel fetal movements starting at 20 weeks, and multiparous women from 18 weeks.
-according to ultrasound. The accuracy of determining the duration of pregnancy according to ultrasound is quite high, especially in the first trimester of pregnancy. In the 2nd and 3rd trimesters, the error in determining the gestational age by this method increases, which is associated with the constitutional features of fetal development or pregnancy complications (fetal hypotrophy, diabetic fetopathy, etc.), so dynamic ultrasound monitoring of the fetus is of some value.
- on maternity leave. According to Ukrainian legislation, from 30 weeks of pregnancy, a woman has the right to prenatal leave.
To quickly calculate the duration of pregnancy and childbirth, special obstetric calendars are issued.
An objective determination of the gestational age in the 1st trimester is possible with a bimanual examination of a woman, because the uterus is located in the small pelvis during these periods. From 16 weeks, the bottom of the uterus is probed over the womb and the gestational age is judged by the height of the bottom of the uterus above the pubic joint, measured with a centimeter tape.
The size of the uterus and the height of its fundus at various stages of pregnancy
| Pregnancy period, weeks | signs |
| A uterus the size of a hen's egg | |
| Womb the size of a goose egg | |
| The uterus is the size of a man's fist, the bottom at the upper edge of the womb | |
| The bottom of the uterus in the middle of the distance between the womb and the navel (6 cm above the womb) | |
| The uterus is at a distance of 11-12 cm above the womb, fetal movements appear, a heartbeat is heard | |
| The bottom of the uterus at the level of the navel, 22-24 cm above the womb | |
| The bottom of the uterus is 4 cm above the navel, 25-28 cm above the womb | |
| The fundus of the uterus is in the middle of the distance between the navel and the xiphoid process, 30-32 cm above the womb, the circumference of the abdomen at the level of the navel is 80-85 cm, the navel is somewhat flattened, the direct size of the head is 9-10 cm | |
| The bottom of the uterus at the costal arches, at the level of the xiphoid process, the abdominal circumference is 90 cm, the navel is smoothed, the straight head size is 10-12 cm | |
| The bottom of the uterus descends to the middle between the navel and the xiphoid process, 32 cm above the womb, the abdominal circumference is 96-98 cm, the navel is protruded, the direct size of the head is 11-12 cm. into the pelvis |
To recognize the gestational age, the correct measurement of the height of the fundus of the uterus above the womb and the volume of the abdomen is of known importance. The measurement of the standing height of the fundus of the uterus in the bosom is carried out with a centimeter tape or a pelvis meter, while the woman lies on her back, her legs are straightened, the bladder is emptied before the study. Measure the distance between the upper edge of the symphysis and the most prominent point of the uterine fundus. In the second half of pregnancy, the circumference of the abdomen is measured with a centimeter tape, which is applied in front to the level of the navel, in the back - to the middle of the lumbar region.
Measuring the length of the intrauterine fetus provides additional data for determining the gestational age. Accurate measurement of the intrauterine fetus is difficult, and the data obtained from this are only indicative. The measurement is made using a tazometer. The woman lies on her back; the bladder must be emptied before measurement. Having felt parts of the fetus through the abdominal wall, one button of the tazomer is placed on the lower pole of the head, the other on the bottom of the uterus, where the buttocks of the fetus are more often located. V.V. Sutugin established that the distance from the lower pole of the head to the pelvic end is exactly half the length of the intrauterine fetus (from the crown of the head to the heels). Therefore, the value obtained by measuring the distance from the lower pole of the head to the buttocks is multiplied by two. Subtract 3-5 cm from the resulting number, depending on the thickness of the abdominal wall. Having determined the length of the fetus, divide this number by 5 and get the gestational age in months.
For convenience of calculations, the following formula is used (Skulsky's formula):
X=((L×2)-5)/5
Where X- estimated gestational age in lunar months; L- the length of the fetus in the uterus when measured by a tazomer; 2 – doubling factor; 5 in the numerator - the thickness of the walls of the abdomen and the walls of the uterus; 5 in the denominator - the number by which the number of months is multiplied to obtain the length of the fetus (according to the Haase formula).
For example:
X=((22.5×2)-5)/5=8
Where 8 is the number of obstetric months, or 32 weeks of pregnancy. To obtain the length of the fetus - the Haase formula:
In the first half of pregnancy (up to 20 weeks) - L= X²
In the second half of pregnancy (after 20 weeks) - L=X×5,
where X is the number of lunar months.
Measurement of the fetal head gives auxiliary numbers to clarify late pregnancy. The woman lies on her back; if possible, they feel the head of the fetus more carefully: the buttons of the tazomer are installed on the most prominent points, which usually correspond to the back of the head and forehead. The frontal-occipital size of the head at the end of the 8th month (32 weeks) of the fetus is on average 9.5 cm, at the end of the 9th month (35-36 weeks) - 11 cm.
According to the formula of I.F Jordania:
Where X- estimated gestational age in weeks; L- the length of the fetus in the uterus measured by a tazomer; WITH - fronto-occipital size.
For example:
If L= 22cm C= 10 cm then X= 32 cm i.e. the gestational age is 32 weeks.
Using all of the above methods for determining the gestational age in the 1st trimester, it is possible to determine the gestational age with an accuracy of the first week. In the 2nd and 3rd trimesters, the possibility of errors in determining the gestational age increases. The use of the ultrasonic scanning method (ultrasound) increases the accuracy of determining the gestational age.
Conclusions:
The midwife should be able to determine the gestational age, the date of birth, the period of maternity leave.
Student know:
– The size of the uterus and the height of its bottom at different stages of pregnancy
– Fetal measurement
– Formulas of Skulsky, Zhordania, Lebedeva