Diagnosis of the narrow pelvis

In clinical terms, the diagnosis of a narrow pelvis should consist of a carefully collected history, general examination of the pregnant or parturient child and internal research. The doctor receives the most important data when collecting an anamnesis - finding out the age, general and infectious diseases that can adversely affect the overall development of the organism (infantilism, hypoplasia) and the correct formation of the pelvis (rickets, bone tuberculosis).

Of the obstetric anamnesis, the most significant are the late onset of menstruation, the disruption of their rhythm, prolonged preterm births with weakness of labor, operative delivery, especially cesarean section, perforation of the uterus and conservative myomectomy, fertile operations, delivery of a large fetus.

With a general external examination, attention is paid to growth - small - 155-145 cm and below, as a prerequisite for a uniformly compressed pelvis; large - 165 cm and above - funnel-shaped pelvis; signs of rickets - flat-lobed, as well as to a simple flat pelvis; lameness, shortening of the leg, change in the shape of the hip joints (one or two) - the presence of squashed pelvis.

The most important for clarifying the shape and especially the degree of pelvic narrowing is the vaginal examination to determine the diagonal conjugate in the most common forms of the pelvis - uniformly flattened and flat: for rare cannulas (irregular shape) - revealing the capacity of the pelvis half, along with measuring and diagonal conjugate.

To judge the degree of narrowing of the kyphotic pelvis, it is necessary to measure the direct and transverse dimensions of the pelvic outlet - the latter normally has a rounded shape with a diameter of the indicated sizes of 10.5-11 cm.

The mechanism or biomechanism of labor with narrow pelvises, especially typical and most common, has been well studied. It has a rather specific character, consisting in adaptive movements of the head to overcome individual obstacles or a general narrowing of the pelvis. In addition, the formation of the birth cancers and the configuration of the head, which reduces its size, facilitating the passage through the narrowed for her pelvis. Without knowledge of these features, it is impossible to understand the course, nor to lead a birth with one form or another of a narrow pelvis.

Among the absolute indications for cesarean section, an anatomically narrow pelvis of the third degree (true conjugate less than 7 cm), sometimes of the second degree in the presence of a large fetus, as well as a clinical incompatibility of the pelvis of the woman and the head of the fetus.

Among the relative indications, there may be an anatomically narrow pelvis of the first and second degree with a true conjugate of 11 to 7 cm. To address the issue of abdominal delivery may also be important in the combination of an anatomically narrow pelvis with the elderly woman, a stillbirth in the anamnesis, pelvic presentation, large fruit, incorrect insertion of the head, etc .; similar women of high-risk groups the doctor in a timely manner sends to a qualified maternity hospital.

In recent times, due to the more frequent development of large fruits, there is often an unfavorable obstetrical situation with normal pelvic size and especially with its initial narrowing. A picture of relative and sometimes more severe clinical insufficiency is created. The large head remains relatively mobile for a relatively long time or slightly pressed against the entrance to the pelvis. This unnecessarily stretches the lower segment during bouts, preventing it from contracting properly, which is now considered necessary for the normal course of labor, leading to a delayed opening of the cervix. In this case, often there is a disciplinary labor activity, accompanied by late departure of amniotic fluid and the development of weakness in labor. The absence of the formation of a generic tumor and a sufficient head configuration to overcome the known resistance from the pelvis creates the prerequisites for the development of a clinically narrow pelvis. While before the vast majority of births even at the first degree of pelvic narrowing ended at 80-90% independently, now due to the large number of large fruits the passage of a large head meets significant, difficult to overcome obstacles, even with normal pelvic dimensions.

The use of antispasmodics, the timely provision of sleep-rest with the subsequent or preliminary creation of estrogen-glucose-vitamin-calcium background, as well as the use of intravaginal gel with prostaglandins and the application of rhodostimulation, along with the prevention of infection and activities improving the viability of the fetus, allows the delivery to end through natural birthmarks.

Often, epidural analgesia, which should be performed by a highly qualified anesthesiologist, has a beneficial (antispasmodic and analgesic) effect for the speedy opening of the cervix and the removal of painful and less productive contractions and the normalization of labor. For the prevention of the development of large fruits, it is necessary to more actively regulate the excess mass of large fruits by dietary and other measures, for the present intrauterine fetal accretion, with the remaining normal pelvic size in women, creates known difficulties in childbirth.

There is a high incidence and manifestation of various complications in labor with a narrow pelvis. There are common complications observed with all narrow pelvises, and some of them are peculiar to individual species (varieties) of narrow cans associated with the specificity of the mechanism of birth.

A common complication of narrow cans is untimely (both premature and early) water drainage, observed 5 times more often than usual. This is explained, as a rule, by the prolonged standing of the head, movable above the entrance to the pelvis or at the entrance to the small pelvis. This is more often observed with flat pelvis, where there is insufficient formation of a contact between the head and the plane of entry into the pelvis, and less often - with a uniformly compressed pelvis. This also explains the more frequent loss of small parts of the fetus and especially unfavorable - the prolapse of the umbilical cord; more delayed opening of the cervix (the collapse of its edges after the passage of water and lack of passage of the head), leading to prolonged labor and a long anhydrous interval and fatigue of the mother in childbirth. An even more unfavorable complication is attachment of the infection (fever in labor and endometritis) and asphyxia of the intrauterine fetus. Often there is a development of primary weakness of labor activity, especially in primiparas. This is due to the need for a long overcoming of the obstacles of the narrowed pelvis. In primiparas, this complication is often associated with general underdevelopment and infantilism, in re-births - with overstretch of the uterus musculature, altered by preceding prolonged births. The secondary weakness of labor is often developed.

With a high-standing or only pressed head and incomplete opening of the uterine throat , untimely or false attempts are detected as an expression of the presence of an obstacle to the progress of the head. This, in the words of the French authors, "scream" of the narrow pelvis. Long standing of the head in one plane of the pelvis causes painful, intense, sometimes convulsive contractions, which sometimes leads to overstretching of the lower segment of the uterus with a high standing of the border roller (Schatz-Unterberger furrow). This is also a signal of a threatening or beginning rupture of the uterus (the appearance of the suprarenal discharge). It is not indifferent to the absence of the head's advance and to squeeze the soft tissues (ischemia of them), the bladder (the appearance of blood in the urine), and in the absence of due attention to these menacing symptoms on the part of the doctor, tissue necrosis and urogenital fistula formation can subsequently occur.

The infringement of the anterior lip of the cervix, manifested by bloody discharge, painful involuntary attempts, requires the timely regulation of the cervix in order to avoid its traumatization and facilitate head advancement. The severely obstructed passage of the head, especially the large one, through the narrowed pelvis, as well as the use of rhythm-operative operations (application of forceps, especially cavities, or vacuum extractors) can lead to rupture of the pubic articulation.

Often, the narrow pelvis causes incorrect positions of the fetus and the insertions of the head (mostly extensor), its passage in large sizes, which usually creates additional difficulties and can lead to the phenomena of the clinically narrow pelvis.

There is a significant number of other complications in the narrow pelvis, which the doctor should not forget. Thus, the number of cases of late diversion of water (more than every third woman in labor), fever during childbirth (in every tenth), intrauterine fetal asphyxia (almost half of women with a narrow pelvis) is especially large .

A large number of violations of the fetus is due in part to the fact that it is established in modern conditions using apparatus research methods (cardiotocography) without obvious clinical manifestations of auscultatory (obstetric stethoscope) changes in fetal heart rate or presence of meconium admixture in the amniotic fluid.

Instrumental measurement of the pelvis. Tazomer in the lying position of women measure the distance between certain points of the skeleton - the protuberances of the bones. Three transverse dimensions are measured :

1. distance between the spines (distantia spinarum), equal to 25-26 cm;
2. distance between scallops (distantia cristarum), equal to 28-29 cm;
3. distance between the large spit (distantia trochanterica), equal to 30-31 cm.

At the same time, the ends of the compass point to the most prominent points of the antero-first spines, to the most outstanding points of the crested bones and the prominent points of the outer surface of large spits.

When measuring the external, direct pelvic size, the woman is in the position on her side, while the foot on which the woman lies should be bent in the hip and knee joints, and the other leg is stretched. One leg of the tasomer is placed on the anterior surface of the symphysis near its upper edge, and the other - into the depression between the last lumbar and I sacral vertebrae - into the upper corner of the Michaelis rhombus. This is the outer direct dimension, or the outer conjugate, which is equal to 20-21 cm. It can also be used to judge the size of the inner true conjugate, for which it is necessary to subtract 9.5-10 cm from the size of the outer konyogata. The internal straight dimension is 11 cm.

There is another size - a side conjugate. This is the distance between the anteroposterior and posterior supernatals of the iliac bones of the same side, which allows us to judge the internal dimensions of the pelvis; in norm it is equal to 14.5-15 cm, and for flat basins it is 13-13.5 cm.

When measuring the transverse dimension of the pelvic outlet, the ends of the tasomer are placed on the inner edges of the ischiadic tubercles and to the resulting 9.5 cm figure add 1-1.5 cm to the thickness of the soft tissues. When measuring the direct size of the pelvic outlet, the ends of the compass are placed on the top of the coccyx and on the lower edge of the symphysis and subtracted from the obtained value 12-12.5 cm by 1.5 cm by the thickness of the sacrum and soft parts. The thickness of the pelvic bones can be judged by the Soloviev index - the area of the circumference of the wrist joint, which, under the normal physique of a woman, is 14.5-15.5 cm.

Then it is necessary to determine the position of the fetus, the type, position and the presenting part by the methods of Leopold. It is very important to determine the position of the head with respect to the plane of entry and the pelvic cavity, which is important for understanding the biomechanism of labor.

1. The head high above the entrance to the pelvis or "balloting" of the head indicates that the latter freely moves to the side when the hand is moved by the obstetrician.
2. The head is pressed to the entrance to the pelvis - head dislocations can not be made, the movement of the head by hand is difficult. Further, the insertion of the head into the pelvis is distinguished by a small, medium and large segment. Expression: "the head with a large segment at the entrance to the pelvis", some obstetricians are replaced by the expression "head in the upper part of the pelvic cavity". The head is a small segment - when only a small part or pole of the head is below the plane of the entrance to the pelvis. The head is a large segment - at the entrance to the pelvis it will be established by the suboccipital fossa and frontal tubercles and the circle drawn through these anatomical boundaries will be the base of a large segment. The head is located in the pelvic cavity - the head is all in the cavity of the small pelvis.

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