Not on days, and on hours. Changes of a uterus during pregnancy of
In an organism of future mother happen numerous changes which allow to take out the child. But does not raise any doubts that the most considerable changes occur in a uterus - body in which new life develops.
A little physiology
the Uterus is a unique body which structure such is that it is capable to stretch and increase during pregnancy the sizes in tens of times and to come back to an initial state after the delivery. In a uterus allocate the most part - the body located from above and smaller part - a neck. Between a body and a neck of a uterus the intermediate site which is called an isthmus is located. The highest part of a body of a uterus is called a bottom.
the Wall of a uterus consists of three layers: internal - an endometriya, an average - a miometriya and external - perimetry (a serous cover).
Endometry - a mucous membrane which changes depending on a phase of a menstrual cycle. And in case pregnancy does not come, endometriya separates and allocated from a uterus together with blood during periods. In case of approach of pregnancy of endometriya it is thickened and provides fetal egg with nutrients on early terms of pregnancy.
the Main part of a wall of a uterus is made by a muscular cover - of miometriya . Due to changes in this cover there is an increase in the sizes of a uterus during pregnancy. Miometry consists of muscle fibers. During pregnancy due to division of muscle cells (miotsit) new muscle fibers are formed, but the main growth of a uterus happens due to lengthening by 10 - 12 times and thickenings (hypertrophy) of muscle fibers by 4 - 5 times which occurs generally in the first half of pregnancy, to the middle of pregnancy thickness of a wall of a uterus reaches 3 - 4 cm. After 20 - y weeks of pregnancy the uterus increases only at the expense of stretching and thinning of walls, and by the end of pregnancy thickness of walls of a uterus decreases to 0,5 - 1 cm
Out of pregnancy the uterus of the woman of reproductive age has the following sizes: length - 7 - 8 cm, the perednezadny size (thickness) - 4 - 5 cm, the cross size (width) - 4 - 6 cm. The uterus about 50 g weighs (at giving birth - to 100 g). By the end of pregnancy the uterus increases several times, reaching the following sizes: length - 37 - 38 cm, the perednezadny size - to 24 cm, the cross size - 25 - 26 cm. Uterus weight by the end of pregnancy reaches 1000 - 1200 without child and fetal covers. At a mnogovodiya, a mnogoplodiya the sizes of a uterus can reach still the big sizes. Uterus cavity volume by ninth month of pregnancy increases by 500 times.
What is considered norm?increase in the sizes of a uterus, change of its consistence (density), a form is characteristic
Of pregnancy.Increase in a uterus begins
in 5 - 6 weeks of pregnancy (at 1 - 2 weeks of a delay), at the same time the body of a uterus increases slightly. At first the uterus increases in a perednezadny size and becomes spherical, and then also the cross size increases. Than pregnancy term is more, especially noticeable is an increase in a uterus. In early terms of pregnancy often there is an asymmetry of a uterus, at bimanualny research protrusion of one of uterus corners is palpated. Protrusion arises from - for growth of fetal egg, in process of pregnancy progressing fetal egg fills all cavity of a uterus and asymmetry of a uterus disappears. By 8 weeks of pregnancy the body of a uterus increases approximately twice, by 10 weeks - by 3 times. By 12 weeks the uterus increases by 4 times and the bottom of a uterus reaches the exit plane from a small pelvis, i.e. upper edge of a lonny joint.by
For an assessment of situation, the sizes, density (consistence) of a uterus conducts two-handled (bimanualny) research. When carrying out bimanualny research the doctor the obstetrician - the gynecologist enters index and average fingers of the right hand into the woman`s vagina, and fingers of the left hand carefully presses on a forward belly wall towards to fingers of the right hand. Advancing and pulling together fingers of both hands, the doctor gropes a uterus body, defines its situation, the size and a consistence.
From the second trimester of pregnancy (with 13 - 14 - y weeks of pregnancy) the uterus goes beyond a small pelvis, and it is possible to probe it through a forward belly wall. Therefore since this term the obstetrician - the gynecologist measures uterus bottom height (VDM - distance between the upper edge of a lonny joint and the highest point of a uterus) and a stomach circle. All measurements register in the individual prenatal record that allows to track dynamics of growth of a uterus and to estimate growth rates. VDM is measured by a centimetric tape or a tazomer (the special device for measurement of distance between two points) in position of the pregnant woman lying on a back. Before measurement and survey it is necessary to empty a bladder.the following indicators of VDM are characteristic
Of the normal (physiological) course of pregnancy:
- in 16 weeks of pregnancy the bottom of a uterus settles down on the middle of distance between a navel and a lonny joint, VDM - 6 - 7 cm;
- in 20 weeks the bottom of a uterus is 2 cm lower than a navel, VDM of 12 - 13 cm;
- in 24 weeks a uterus bottom at the level of a navel, VDM of 20 - 24 cm;
- in 28 weeks the bottom of a uterus is 2 - 3 cm higher than a navel, VDM - 24 - 28 cm;
- in 32 weeks a uterus bottom in the middle between a navel and a xiphoidal shoot (the lower part of a breast), VDM - 28 - 30 cm;
- in 36 weeks the bottom of a uterus rises to a xiphoidal shoot and costal arches. In this term the highest arrangement of a bottom of a uterus is observed. VDM - 32 - 34 cm;
- at the end of pregnancy (in 38 - 40 weeks) the bottom of a uterus falls, VDM - 28 - 32 cm
at the same time influences height of standing of a uterus the size and the provision of a fruit, amount of amniotic liquid, polycarpous pregnancy. At a large fruit, twins, a mnogovodiya the uterus stretches more, and respectively, the bottom of a uterus will be higher. At slanting or cross VDM there can be less norm. Also it is necessary to pay attention that uterus bottom height at the same term of pregnancy at different women fluctuates on 2 - 4 cm due to specific features therefore at determination of term of pregnancy are never guided only by the uterus sizes. Also other indicators, such as date of the last periods, date of the first stir of a fruit, results of ultrasonic research are considered.
As a uterus estimates a condition?If in the first trimester of pregnancy the condition of a uterus is estimated by
at bimanualny research, then approximately from fourth month for an assessment of progressing of pregnancy and a condition of a uterus the doctor the obstetrician - the gynecologist uses four receptions of external obstetric research (Leopold`s receptions):the doctor has
- At the first reception of external obstetric research palms of both hands on the most top part of a uterus (bottom), at the same time VDM, compliance of this indicator to term of pregnancy and the part of a fruit located in day of a uterus is defined. the doctor moves with
- At the second reception of external obstetric research both hands from a uterus bottom to the level of a navel from top to bottom and has on lateral surfaces of a uterus then makes a serial palpation of parts of a fruit the right and left hand. At the longitudinal provision of a fruit on the one hand the back, with another - small parts of a fruit is probed (hands and legs). The back is probed in the form of the uniform platform, small parts - in the form of small ledges which can change the situation. The second reception allows to define a tone of a uterus and its excitability (reduction of a uterus in response to a palpation), and also a fruit position. At the first position the back of a fruit is turned to the left, at the second - to the right. by
- At the third reception the obstetrician - the gynecologist determines the prelying part of a fruit - it is that part of a fruit which is turned to an entrance to a small pelvis and the first passes patrimonial ways (more often it is a fruit head). The doctor costs on the right, face to face the pregnant woman. One hand (as a rule, right) carries out a palpation a little above a lonny joint, therefore, that the thumb is on one party, and four others - on other party of the lower part of a uterus. The head is probed in the form of dense roundish part with accurate contours, the pelvic end - in the form of the volume softish part which does not have rounded shape. At the cross or slanting provision of a fruit the prelying part is not defined.
- At the fourth reception the palpation (palpation) of a uterus is run by two hands, at the same time the doctor becomes facing the pregnant woman`s legs. Palms of both hands have on the lower segment of a uterus on the right and at the left, the extended fingers carefully palpate height of its standing and the prelying part of a fruit. This reception allows to define an arrangement of the prelying part of a fruit concerning an entrance to a small pelvis of mother (the prelying part over an entrance to a small pelvis, is pressed to an entrance, fell to a basin cavity). If the head predlezhit, then the obstetrician determines its size, density of her bones and gradual lowering in a small pelvis at the time of delivery.
very carefully and carefully as the sharp movements can cause the reflex tension of muscles of a forward belly wall and increase of a tone of a uterus.
In time carrying out external obstetric inspection the doctor estimates a tone of muscles of a uterus. Normal the wall of a uterus has to be soft, at increase of a tone of a uterus the wall of a uterus becomes firm. The raised tone (hyper tone) of a uterus is one of pregnancy interruption threat signs, it can arise on any term, at the same time the woman, as a rule, feels pains in the bottom of a stomach and a waist. Pains can be insignificant, sipping or very strong. Expressiveness of a painful symptom depends on a threshold of painful sensitivity, duration and intensity of a hyper tone of a uterus. If the raised tone of a uterus arises quickly, then pain or heavy feeling in the bottom of a stomach most often insignificant. At a long hyper tone of muscles of a uterus the painful symptom which was usually more expressed.
What is felt by the woman?Should emphasize
that at physiological pregnancy the woman most often does not feel growth of a uterus as process of increase in a uterus happens gradually and smoothly. At the beginning of pregnancy the woman can note the unusual feelings in the bottom of a stomach connected with change of structure of uterine sheaves (they “are softened“). At rapid growth of a uterus (for example, at a mnogovodiya or polycarpous pregnancy), at adhesive process in an abdominal cavity, at a deviation of a uterus of a kzada (most often the uterus is inclined kpered), in the presence of a hem on a uterus after various operations there can be pain. It is necessary to remember that at emergence of any pain the obstetrician needs to see as soon as possible a doctor - the gynecologist.many women feel by
several weeks prior to childbirth so-called fights - harbingers (Braxton`s fights - Hicks). They have character of nagging pains in the bottom of a stomach and in the field of a sacrum, have irregular character, short on duration or represent increase of a tone of a uterus which the woman feels as tension which is not followed by painful feelings. Fights - harbingers do not cause shortening and opening of a neck of a uterus and are peculiar “training“ before childbirth.
After the delivery
After the birth of the child and an afterbirth already during the first hours of the postnatal period considerable reduction (reduction in sizes) a uterus happens. Uterus bottom height during the first hours after the delivery makes 15 - 20 cm. Restoration of a uterus after the delivery is called involution. Within the first two weeks after the delivery the bottom of a uterus falls daily approximately by 1 cm
- B 1 - 2 - e days after the delivery the bottom of a uterus is at the level of a navel - VDM of 12 - 15 cm;
- on 4 - e days of VDM - 9 - 11 cm;
- on 6 - e days of VDM - 9 - 10 cm;
- on 8 - e days of VDM - 7 - 8 cm;
- on 10 - e days of VDM - 5 - 6 cm; - e days the bottom of a uterus is located
- on 12 - 14 at the level of connection of pubic bones.
to the sizes which were before childbirth, approximately in 6 - 8 weeks. The return development of a uterus depends on a set of various factors: features of a course of pregnancy and childbirth, feeding by a breast, age of the woman, the general state, the number of childbirth in the anamnesis. The uterus is reduced more slowly at women 30 years, at the weakened and multigiving birth women are more senior, later there are a lot of fetal pregnancy and pregnancies, complicated by abundance of water, at a miomematka, and also at emergence of an inflammation in a uterus (endometritis) during pregnancy, childbirth or the postnatal period. At the feeding women involution of a uterus happens quicker as when feeding the breast produces hormone oxytocin which promotes reduction of a uterus.