Bone birth canal dystocia
Introduction
Abnormal manifestation of abnormal birth canal Abnormal bone birth canal refers to pelvic stenosis, and any diameter or several diameters of the pelvis are shortened, called pelvic stenosis. The pelvis can be narrowed simultaneously in one or more of the three planes of the entrance, the middle pelvis, and the outlet. When a radial line is narrow, it is necessary to observe the size of other radial lines in the same plane, and then comprehensively measure the size and shape of the entire pelvis, in order to accurately estimate the impact of this pelvis on the composition of dystocia, which is often encountered in clinical practice. Is critical or mild pelvic stenosis, whether it will constitute a difficult relationship with the size and position of the fetus, the plasticity of the fetal head, productivity, soft tissue resistance and timely and correct treatment, in addition, due to congenital abnormalities And the abnormal pelvis caused by acquired diseases is also abnormal in the birth canal. basic knowledge The proportion of illness: 0.04% - 0.07% Susceptible people: good for pregnant women Mode of infection: non-infectious Complications: premature rupture of membranes
Cause
Abnormal birth dystocia
Causes:
Developmental pelvic abnormalities:
The pelvis is affected by ethnic, genetic, and nutritional factors during its development. Its shape and size vary from person to person. Shapiro is divided into four types according to pelvic morphology: female, male, flat, and sputum. In fact, the pelvis that fully conforms to these four forms are rare, and most of them are mixed types.
Vitamin D deficiency disease pelvis:
Due to insufficient supply of vitamin D in childhood or long-term lack of sun exposure, the formation of vitamin D deficiency pelvis is mainly due to the weight of the patient's body weight and the mechanical effect of muscle ligament on pelvic traction, followed by the pathology of pelvic bone during development. Change is now rare.
Osteomala pelvis:
Vitamin D deficiency occurs when the osteophytes are closed in adults and are called osteomalacia.
Pelvic fractures:
Most often after a car accident or a fall.
Pelvic tumor:
rare. Pelvic chondroma, osteoma, chondrosarcoma have been reported.
Prevention
Abnormal birth dystocia prevention
There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.
Complication
Abnormal dystocia complications of the bone canal Complications premature rupture of the uterus
1. Premature rupture of membranes: the size of the head basin is not called and the position of the fetal head is abnormal. It may be because the fetal head can not adapt to the pelvic entrance plane, so that the fetal head is blocked, sometimes the fetal head is even in a high floating state, the fetal head and pelvic inlet There is a large gap between them, so that the amniotic fluid enters the anterior amniotic fluid sac from this gap. When the uterus shrinks, the membrane is naturally ruptured because it cannot withstand strong pressure. Therefore, premature rupture of membranes is often a sign of dystocia. It must be pointed out that the membrane Premature rupture can also be caused by chorioamnionitis. It can be seen that dystocia is not caused by premature rupture of membranes, but the incidence of premature rupture of membranes in dystocia is higher than normal.
2. Primary uterine contraction: refers to the uterine contraction is too weak or uncoordinated at the beginning of labor, sometimes difficult to identify with false labor, such as the use of strong sedative after uterine contraction becomes regular, powerful, rapid progress in labor That is, the uterine contraction weakness is converted into coordinated uterine contraction; if the uterine contraction is completely stopped with a strong sedative, the pregnant woman can return to normal life, that is, the temporary labor; if the uterine contraction does not stop or change to normal uterine contraction after administration, It should be considered that the organic factors (such as the head basin is not called, the abnormal position of the fetal head) cause early manifestations of obstructive delivery.
3. Increasing latency: The consequence of primary uterine contraction fatigue is often the prolongation of incubation period. The general average latency is 6-8h, the upper limit is 16-20h, and the Chinese textbook is determined to be 16h. The incubation period is longer than 16h. It must be pointed out that the incubation period is More than 8h should be considered to have a tendency to prolong, need to be dealt with, the incubation period is prolonged, the abnormality of the head and the abnormal position of the fetal head are higher than the normal incubation period, so the incubation period is prolonged by multiple organic factors.
4. The fetal head is not connected or delayed. The signs that the maternal head has not been connected after the delivery may be related to the pelvic entrance pattern. There is no need to worry too much, but the labor process should be closely observed. However, the fetal head is high and the height is at -3cm. Or -3cm or more must be vigilant. Under normal circumstances, when the cervix is 5cm, the fetal head should be connected. If the cervix is 5cm after the cervical dilatation, the fetal head is called delayed connection, indicating that the fetal head has encountered difficulties when passing the pelvic entrance plane. If the uterus expands 5cm and then opens, the fetal head is always unable to connect, and the fetal head is not connected. This indicates that the fetal head has a serious head basin in the pelvic entrance plane and the head position is abnormal.
5. Cervical dilatation delay: primipara cervix dilatation accelerates after entering the active period. It is generally considered that the uterine cervix is 3 to 4 cm when it is accelerated, 4 to 9 cm is the maximum acceleration phase, and 9 to 10 cm (Miyaguchi is full) is the deceleration phase. The maximum acceleration phase is 1.2cm/h. The uterus expansion rate is less than 1.2cm/h or the maternal <1.5cm/h is active in the cervical dilatation. Many scholars at home and abroad have denied normal birth. Deceleration period exists, so the deceleration of the cervix after expansion to 9cm should be suspected of abnormal conditions. If the cervix has not been opened for more than 3 hours, except for the abnormal position of the fetal head, it is likely to be accompanied by a narrow sacral and pelvic outlet plane.
6. Cervical dilatation block: Cervical dilatation block refers to the active cervix to stop dilating for more than 2 hours, no progress in labor, occurs in the early active stage (cervical dilatation 3 ~ 4cm), suggesting that the head basin is in the plane of the entrance to the pelvis Not called or the abnormal position of the fetal head (such as high straight position, front uneven position, posterior position, position, etc.), so that the fetal head can not be connected, the cervix is difficult to continue to expand, although the contraction is barely expanded to 5 to 6 cm, but the contractions are retracted to 3 to 4 cm, and there is little progress after treatment. It is often necessary to end the delivery with cesarean section. When the cervix is expanded to 6-8 cm, the cervical dilatation is stagnant. Sexual cervical dilatation block is considered to be a more serious phenomenon. First of all, it should be thought that the head basin is not called. We observe that the blockage occurs in a more advanced stage, and the head basin is not called a combined minor head position abnormality. Obviously the head basin does not call the posterior intravenous infusion of oxytocin, which promotes the fetal head transposition, and the labor process is still likely to progress. In short, the cervical dilatation block is more serious than the cervical dilatation delay, and the prognosis of delivery is also worse.
It is worth noting that the clinical manifestations of simple cervical dilatation delay and cervical dilatation block may also be manifested as delayed cervical dilatation for a period of time without treatment, and conversion to cervical dilatation block or blockade after treatment is delayed. Therefore, it is common in the clinic to have mixed cervical dilatation abnormalities that are accompanied by delay and block.
7. Prolonged active period: abnormal performance of cervical dilatation delay and block system, no need to be the final diagnosis of the disease, whether the cervical dilatation is delayed, block or both coexist and the cervical dilatation active period exceeds 8h, said For the prolongation of the active period, this diagnosis has a clear clinical significance, 95% of the maternal normal active period ends within 8h, and more than 8h is abnormal for labor.
8. Active period stagnation: active period of cervical dilatation delay and / or blockade after treatment, the labor process has not continued to progress, the cervix has not been able to complete, but had to end the delivery by cesarean section, called active stagnation, The prolonged active period and the stagnation of active period are the result of abnormal cervical dilatation. The cervix of the former is still open, and the latter is not fully opened. Therefore, the dystocia of the latter is more serious than the former. The former may have vaginal delivery, the latter. Childbirth must be completed with a cesarean section.
9. Secondary uterine contraction: refers to the abnormal uterine contraction after a period of labor, which is relatively easy to identify. Secondary uterine contraction is mostly caused by abnormality of the head basin, abnormal position of the fetal head, and other organic factors. The consequences caused by the increased resistance of the fetal head, if not treated in time, will lead to prolonged labor, maternal failure (dehydration, acid-base imbalance, etc.), if it is treated at this time, even if the abnormal factors are not serious, you have to have cesarean section End the birth.
10. Delay or block of fetal head decline: The rapid decline of fetal head is in the deceleration phase of the cervical dilatation phase and the second stage of labor, that is, after the cervix is nearly open and full, the primipara falls in the fetal head rapidly descending stage. The rate <1cm/h is the delay of the fetal head decline. If the decline stops for more than 1h and no progress is the fetal head drop block, the decrease of the block rate is more unfavorable. The abnormal fetal head drop suggests that the fetal head meets in the middle pelvis-pelvic outlet plane. To the difficulty, often due to the head basin not called or the abnormal position of the fetal head, the abnormal position of the fetal head is most common with the persistent posterior occipital position and the occipital transverse position. Other more serious fetal head position abnormalities such as high straight position and unequal unevenness Tilt and position, often encountered difficulties in the pelvic entrance plane, prolonged labor, maternal failure, secondary uterine contraction, or because the mother does not breathe down, can cause abnormal fetal head decline, maternal downward breath The force generated by increasing abdominal pressure accounts for 50% of the total productivity during this period. Therefore, it is very important to correctly guide the mother's breath holding during the rapid decline of the fetal head.
11. The second stage of labor extension: the primipara from the cervix to the fetus delivered more than 2h, the maternal more than 1h, called the second stage of labor extension, the second stage of labor is divided into 2 stages, the decline period and the pelvic stage, the cervix After the primipara maternal head reaches the pelvic floor, the descending period should be completed within 20 to 50 minutes. After the fetal head reaches the pelvic floor, the fetus is delivered to the pelvic floor. The pelvic floor should not exceed 20 uterine contractions. It takes 20 to 40 minutes. The abnormality of the descending period should consider the possibility that the pelvic outlet head basin is not called. There is basically no pelvic problem in the pelvic floor period. The pelvic period prolonged resistance is mostly from the pelvic floor soft tissue and the vaginal opening, the perineum, and the second stage of labor is divided into two. The two phases are conducive to the early detection of abnormal conditions in the decline period, so as to be dealt with in time. The second stage of labor for normal primipara is usually about 1h, and 95% of the mothers are less than 2h, so 2h is defined as the boundary between normal and abnormal. When the second stage of labor is prolonged, the fetal body is under hypoxic or damaged due to excessive pressure on the fetal head; the mother is easily prone to postpartum hemorrhage due to abnormal productivity.
Symptom
Abnormal manifestations of dystocia in the common part of the birth canal Symptoms of fatigue, stenosis, pelvic flat pelvis, postpartum poor prolongation, flat pelvic birth canal, laceration, occipital transverse position, pelvic basin, non- sexual pelvic floor, hematoma
1. Classification by pelvic stenosis plane
(1) Inlet stenosis: Most of the performance is that the anteroposterior diameter of the entrance plane is narrow, that is, flat stenosis.
(2) Middle pelvis-export stenosis: The narrow stenosis referred to here refers to the narrow exit surface around the bone. Because it is very close to the middle pelvis, it is similar in size and shape, even slightly smaller than the middle pelvis. It is the last vaginal delivery. Guan, so the fact that the outlet is narrow also suggests a middle pelvic stenosis. Therefore, Benson believes that the middle pelvis is the same as the exit surface, and proposes the concept of dystocia in the middle pelvis-export surface.
The middle pelvis-outlet stenosis, also known as the funnel-type stenosis, is divided into three types:
1 The pelvis and the exit surface are narrow in diameter: the two sides of the pelvis are cohesive, and are common in the apes-like pelvis flat pelvis;
2 The posterior diameter of the pelvis and the outlet is narrow: the anterior and posterior walls of the pelvis are cohesive, and the multi-line tibia is straight and simple;
3 mixed type: the transverse diameter and the anteroposterior diameter of the middle pelvis and the outlet surface are narrow, the two sides of the pelvis and the front and rear walls are cohesive, common in the male pelvis, the narrow diameter of the middle pelvis and the outlet surface is narrow and the mixed type pelvis is easy. Sustained posterior occipital position occurs because the axillary type and the anterior half of the male pelvis are narrow, and the posterior half is wide. The fetal head is often placed in the posterior position of the occipital region, but the longitudinal diameter of the fetal head is difficult to advance in the middle pelvic plane with narrow transverse diameter. Rotating 135o becomes the anterior position of the occipital, and the entrance surface of the posterior sacral pelvis in the middle pelvis and the outlet is mostly flat. The fetal head is inserted into the basin with the occipital transverse position. Because the anterior and posterior diameter of the middle pelvis is narrow and the transverse diameter is normal, the fetal head continues to the pillow. Horizontal position, even directly to the pelvic floor, if the fetus is not large, it may be rotated by hand to the front of the occipital position; if the fetus is slightly larger, it is prone to obstructive dystocia, and the delivery must be completed by cesarean section.
Middle pelvis-storage stenosis with narrow outlet and normal entrance surface, the fetal head can be connected to the basin, but the fetal head falls slowly or even stagnates after arriving in the pelvis. The clinical manifestation is normal in the first half of the first stage of labor, and the first stage of labor is at the end. Cervical dilatation is delayed or stagnant, and the second stage of labor is prolonged. Therefore, when the cervix has been opened, the first dew of the uterus is lowered to the level below the level of the ischial spine. It should be noted whether the funnel-type pelvis is narrow, and whether the fetal head is a continuous occipital or posterior occipital At this time, it must not be blinded by the illusion that the fetal head has entered the pelvic floor caused by severe deformation and edema of the fetal head, and blindly decides to assist the vaginal delivery, otherwise it will bring great harm to the mother and child. If the funnel-type pelvic stenosis, it is not suitable for trial production for too long, should be relaxed cesarean section indications, severe stenosis should be selective cesarean section.
(3) Entrance, middle pelvis and outlet are narrow (both small and narrow): when the pelvic entrance, the middle pelvis and the exit plane are narrow, they are all small and narrow, and can be divided into three types:
1 The shape of the pelvis still maintains the shape of the female pelvis, and only the diameter of each plane is less than the normal value of 1 to 3 cm, and the small pelvis is more common in women with poor stature;
2 simple flat pelvis, but the anteroposterior diameter of the three planes is shortened;
3 types of human pelvis, the transverse diameter of the three planes are small, the most common among the three types, although the pelvis has a slightly smaller diameter, if the fetus is not large, the fetal position is normal, the productivity is strong, and sometimes the vaginal delivery can also be made. However, due to the poor development of the whole body, most of the uterine contraction is weak, and surgery is needed. If the fetus is large, or the fetal head is a persistent posterior or occipital position, the chance of dystocia is greater, so it is small. The pelvic cesarean section indications should not be too tight.
Pelvic abnormality classification Pelvic morphological abnormalities are divided into three categories:
1 developmental pelvic abnormalities;
2 pelvic disease or injury;
3 Pelvic abnormalities caused by spinal, hip and lower limb diseases.
(1) Developmental pelvic abnormalities: The development of pelvis is affected by race, genetics, nutrition and other factors. Its shape and size vary from person to person. Shapiro is divided into 4 types according to different pelvic morphology, namely female type, male type, flat. Types and sputum types, in fact, are completely different from the pelvis of these four forms, and most of them are characterized by their mixed type and four basic forms of pelvis.
1 female pelvis: the most common, the so-called normal pelvis, the transverse diameter of the pelvic entrance surface is slightly longer than the anterior-posterior diameter, which is a horizontal ellipse, which is conducive to childbirth. The fetal head is often placed in the anterior or occipital position. However, If the pelvic cavity is evenly narrow, it is a small pelvis, which is not conducive to childbirth.
2 male pelvis: the entrance surface of the pelvis is chicken heart-shaped or wedge-shaped, the two side walls are cohesive, the pubic arch is small, the ischial spine is prominent, the squatting is narrow, the diameter of the ischial spine is <9cm, and the lower third of the tibia is tilted forward. The front diameter of the pelvis is shortened, so the front and rear walls of the pelvis are also cohesive, forming a so-called funnel-shaped pelvis. This type of pelvis is most unfavorable for the connection of the fetal head. The fetal head is often placed in the horizontal position of the pillow or the back of the pillow. Both the diameter and the transverse diameter are short, which is not conducive to the rotation and lowering of the fetal head. Therefore, it often lasts in the occipital or posterior position, and many of them have to undergo cesarean section.
3 flat pelvis: the flat pelvis has a short posterior diameter and a relatively long transverse diameter. The transverse pelvis is shallow, the pelvis is shallow, the side wall is erect, the shaman's posterior horn and the pubic horn are wide, and the ischial spine is slightly protruding. The diameter of the ischial spine is larger, the squatting is narrower, the tibia is wide and short, and the fetal head is often placed in the basin with the occipital position. Once the entrance surface is passed, the delivery may proceed smoothly.
4 kinds of human pelvis type pelvis: the anterior and posterior pelvis of the human pelvis type are long, the transverse diameter is short, the longitudinal ellipse is deep, the pelvis is deep, the side wall is erect, slightly cohesive, the ischial spine is slightly protruding, the diameter of the ischial spine is short, and the squat is notched. Wide, long and narrow humerus, the fetal head often enters the basin in the back of the pillow, and continues in the back of the pillow. If the productivity is good, the fetal head can be lowered to the bottom of the pelvis and can be transferred to the right posterior position.
(2) Pelvic disease or injury:
1 Vitamin D deficiency disease pelvis: due to insufficient supply of vitamin D in childhood or long-term sun exposure, the formation of vitamin D deficiency pelvis is mainly due to the pressure of the patient's weight and the mechanical effect of muscle ligament on the pelvic traction, followed by the pelvis The pathological changes of bone during development are rare. The main features of the pelvis are: wide and short tibia. The tibia is tilted forward due to the pressure of the weight of the trunk. The pelvic cavity protrudes from the pelvis. Shape, the anteroposterior diameter is obviously shortened. If the sacrospinous ligament is slack, the end of the humerus is posteriorly tilted, and only the posterior anterior posterior diameter is shortened: if the sacral ligament is firm, the tibia is deep curved or hook-shaped, so that the entrance surface and the exit face The diameter is shortened; the pelvic side wall is erect and even abducted, the transverse diameter of the outlet is increased, and the vitamin D deficiency is severely deformed by the pelvis, which is extremely unfavorable for childbirth, so it is not suitable for trial production.
2 osteomalacia pelvis: Vitamin D deficiency occurs in adults with osteophytes closed, called osteomalacia, the main features of the pelvis: due to the weight of the trunk and the support of the inner femur on both sides, and adjacent muscle groups, The ligament is highly deformed, but disproportionate; the anterior and posterior diameters of the pelvis are shortened and the "concave triangle" is formed. The middle pelvis is significantly reduced, the anterior and posterior diameter of the exit is also severely reduced, and the fetus is completely unable to deliver through the vagina. Even if the fetus is dead, because the fetal head can not enter the basin, it can not be performed through the vagina. Only the cesarean section can be taken. The osteomala pelvis is now extremely rare.
3 pelvic fractures: more often after a car accident or a fall injury, the fracture site is more common in bilateral pubic symphysis, ischial branch and humeral wing, severe pelvic fracture can be cured after pelvic deformity and obvious osteophyte formation, obstruction of childbirth, pelvic fracture After healing, pelvic radiography is very important, which can provide a basis for future vaginal delivery. After pregnancy, you should carefully check the pelvis to determine whether there is any abnormality in the pelvis.
4 pelvic tumors: rare, pelvic chondroma, osteoma, chondrosarcoma have been reported, can be found in the posterior wall of the pelvis near the ankle joint, the tumor protrudes into the pelvic cavity, can hinder the decline of the fetal head during labor, resulting in dystocia.
(3) Pelvic abnormalities caused by spinal, hip or lower limb diseases:
1 Spinal lesions of the pelvis: Spinal lesions are mostly caused by bone tuberculosis, which can lead to the following two types of deformed pelvis:
A. kyphosis (humpback) pelvis, mainly caused by tuberculosis and vitamin D deficiency. The kyphosis has different effects on the pelvis. The lower the lesion, the greater the impact on the pelvis. If the kyphosis occurs in the thoracic vertebrae , if there is no effect on the pelvis; if the kyphosis occurs in the chest and below the waist, it can cause the anterior and posterior diameters and transverse diameters of the middle pelvis and the outlet to be shortened, forming a typical funnel-shaped pelvis, which can cause obstructive dystocia during childbirth, due to the high deformation of the spine. Compression of the thorax, reducing the volume of the chest, increasing the pressure on the heart and lungs, the lung capacity is only half of the normal person, the right ventricle must increase the pressure to maintain the increasing blood flow to the lungs due to pregnancy, resulting in increased right ventricular load, right ventricle Hypertrophy, therefore, hunchback affects cardiopulmonary function, and should be strengthened during pregnancy and delivery to prevent heart failure.
B. Scoliosis pelvis, if the scoliosis only affects the thoracic segment of the spine, the pelvis is not affected; if scoliosis occurs in the lumbar spine, the humerus is offset to the opposite side, causing the pelvis to deflect, asymmetrical and affecting childbirth.
2 Hip and lower extremity lesional pelvis: hip arthritis (mostly tuberculosis), poliomyelitis, lower extremity spasm, knee or ankle joint disease, etc., such as in the early onset can cause lameness, due to limb shortening or pain during walking Can not land, the full weight of the limbs, the result of the formation of a skewed pelvis, due to dysfunction of the affected side, the affected side of the flap and hip bone hypoplasia or atrophic changes, more severe pelvic deflection, post-pregnancy, skew The pelvis is not good for childbirth.
3. The extent of pelvic stenosis There is currently no uniform standard for the classification of pelvic stenosis, mainly because of inconsistent methods for measuring pelvis. There are three methods for measuring pelvis, namely clinical measurement, X-ray measurement and ultrasound. Measurement, because X-ray may cause harm to the fetus, most people do not advocate the use of X-ray to measure the pelvis, at least should not be routinely applied. Ultrasound measurement is not yet widely used in clinical practice, so clinical measurement is still the main method to measure pelvic size. Due to the thickness of the bone, it is sometimes necessary to correct it. In particular, the outer diameter of the pubic surface of the pelvis is most affected by the bone. Therefore, the wrist circumference should be measured to understand the thickness of the bone to correct it, or to measure the diagonal inside. The diameter (not affected by bone thickening) is checked.
The degree of pelvic stenosis is generally divided into 3 grades, grade I: critical stenosis, that is, the diameter line is at a critical value (the boundary between normal and abnormal values), and the maternal labor process must be carefully observed, but the vast majority of cases can be delivered naturally; Grade II: Relative stenosis, including a wide range, light, medium and severe stenosis. These cases require a certain period of time after trial production to determine whether it is possible to deliver from the vagina, and the possibility of vaginal delivery during severe stenosis. Small; Grade III: Absolute stenosis, without the possibility of vaginal delivery, must be delivered by cesarean section.
(1) The entrance plane is narrow: the sulcus of the entrance plane is narrower than the transverse diameter. The diameter of the entrance pupil is narrowed according to the outer diameter of the shame (outer combined diameter), the anteroposterior diameter of the entrance plane (true combined diameter) and the length of the diagonal path. Divided into 3 levels.
(2) Middle pelvic stenosis: According to the diameter of the ischial spine, the length of the sagittal diameter of the ischial spine and the length of the anteroposterior diameter of the middle pelvis, the middle pelvic stenosis can be divided into 3 grades, and the diameter of the ischial spine and the posterior sagittal diameter need X. The line was measured, and the anterior and posterior diameter of the middle pelvis was measured by vaginal examination (internal measurement).
(3) Stenosis of the exit plane: The diameter of the pelvic outlet is the most clinically significant for the ischial tuberosity (outlet diameter) and posterior sagittal diameter, while the former is more important, such as the shorter diameter of the ischial tuberosity, the pubic arch The angle becomes sharper, and the available area in front of the exit is reduced. For example, the posterior sagittal diameter has sufficient length to compensate for the lack of diameter between the ischial nodules, and the fetus may still be delivered, but if the ischial nodule is too short ( 6cm), even if the posterior sagittal diameter is large, it can not be compensated. For the classification of the outlet plane stenosis, in addition to measuring the diameter of the ischial tuberosity, the sagittal diameter of the ischial tuberosity is also referred to the front and rear diameter of the exit. The size of the exit and the posterior diameter of the exit is the linear distance from the pubic symphysis to the appendix joint. It is also the exit diameter that the fetal head must pass. If the diameter is short, the fetal head often needs to be in the occipital transverse position to pass the double top diameter. This diameter has a normal value of 11.8 cm and a minimum of l0 cm.
The stenosis of the outlet plane can be divided into three grades according to the diameter of the ischial tuberosity, the length of the sagittal and posterior diameter of the ischial tuberosity.
Examine
Examination of abnormal birth dystocia
1. X-ray pelvic measurement: X-ray film pelvic measurement is more accurate than clinical measurement, can directly measure the diameter of the pelvis and pelvic inclination, and can understand the shape of the pelvic entrance surface and the tibia, the position of the fetal head is high and low. The situation is determined to determine whether there are abnormalities in these areas, but since X-rays may cause radioactive damage to pregnant women and fetuses, most obstetricians at home and abroad believe that they are only used when necessary.
2.B super-pelvic measurement: pelvic measurement is an important basis for diagnosing the head basin and determining the mode of delivery. Because the X-ray pelvic measurement is unfavorable to the fetus, it is rarely used in obstetrics. The clinical pelvic measurement is simple but accurate. Poor, starting in 1991, Peking Union Medical College Hospital, Xu Xuming and other methods to explore vaginal ultrasound pelvis measurement to help diagnose the head basin is not called, the method is as follows:
(1) vaginal ultrasound measurement of pelvic size at 28 to 35 weeks of gestation: the bladder is taken after the pregnant woman emptys the bladder, and the vaginal ultrasound probe is placed in the vagina 3 to 5 cm. When the screen shows both the pubic bone and the tibia, the pelvis is measured. The longitudinal section can measure the anterior and posterior diameter of the pelvic cavity. The anterior site is the medial side of the pubic symphysis, and the posterior site is between the 4th and 5th vertebrae. Then the vaginal probe is rotated 90o. The handle sinks to make the pelvic boundary clear and symmetrical. The ground shows that the transverse section of the pelvis can measure the transverse diameter of the pelvic cavity. The two points at the two ends are the most prominent points of the ischial spine. According to the anteroposterior diameter and transverse diameter of the pelvic cavity, the pelvis can be calculated separately by using the elliptical circumference and area formula. Mid-cavity circumference and mid-cavity area.
(2) 1 week before the third trimester of pregnancy, the abdominal double-top diameter and the pillow front diameter were measured with abdominal B-ultrasound, and the head circumference was calculated.
Diagnosis
Diagnosis and diagnosis of abnormal dystocia in the bone canal
diagnosis
History
If you have the following medical history, such as vitamin D deficiency, osteomalosis, poliomyelitis, spinal and hip tuberculosis, severe thoracic or spinal deformity, pelvic fractures and cesarean section, vaginal surgery midwifery, repeated hip A woman with a position or a horizontal position, a stillbirth, a birth injury, etc. should be carefully examined for pelvic abnormalities.
2. Physical examination
(1) General examination: short stature, less than 145cm of the mother, suffering from small stenosis of the pelvis is more likely, the body is thick, the neck is short, the bones are masculine tendencies, not only because of its thick bone affects the bone The size of the pelvis is also easy to be accompanied by a funnel-type stenosis. The lower limbs are unequal in length and can cause pelvic deformities. Therefore, it is necessary to carefully check whether there are any lower limb or spinal diseases affecting the pelvic morphology, and whether there is vitamin D deficiency or sequelae of pelvic fracture.
(2) Pelvic measurement:
1 Measurement outside the pelvis: Due to the influence of physiological factors such as bone thickness and abduction and eversion of the pelvis, the measurement outside the pelvis does not truly reflect the size of the birth canal. Therefore, some scholars advocate that it is not used, but most scholars believe that the measurement method outside the pelvis is simple. Easy to understand, can initially understand the size of the pelvis, still available for clinical treatment reference, A. shame outer diameter <18cm, suggesting that the posterior diameter of the entrance is narrow, often flat pelvis, B. ischial tuberosity <7.5cm, should Considering the narrow diameter of the outlet, often accompanied by pelvic stenosis, C. sciatic nodular diameter after the sagittal diameter <15cm or pubic arch angle is acute and the pubic arch is low, also suggesting that the outlet is narrow, D. Mi's diamond asymmetry, If the sides are not equal, it may be a skewed pelvis. E. The extra-pelvic measurement of each diameter is 2cm or more smaller than the normal value, suggesting that the small pelvic stenosis.
When measuring outside the pelvis, it should be noted that: A. When measuring the distance between the anterior superior iliac spine and the intercondylar diameter, the two ends of the measuring device should be placed at the outer edge of the anatomical point to avoid the error of the sliding of the measuring device. B. Measuring the outer diameter of the sham At the same time, one end of the measuring device should be as close as possible to the base of the clitoris in front of the pubic symphysis, avoiding the error in sliding into the upper edge of the pubic symphysis. C. The thickness of the bone has a direct influence on the reliability of the external measuring diameter.
If the external measurement is the same value, the women with thin bones and thicker bones have larger pelvic cavity, and the circumference of the lower forearm (referred to as wrist circumference) is measured by the ruler around the right ulnar styloid process and the sacral styloid process. As the index of bone thickness, the average index of women in China is 14cm, the bone quality is thicker than >14cm, the bone is thinner than <14cm, when the wrist circumference is 14cm, the anterior and posterior diameter of the pelvic entrance = the outer diameter of the shame is -8cm, wrist For each additional 1cm, the outer diameter of the shame should be reduced by 0.5cm, and the outer circumference of the wrist should be reduced by 1cm. The outer diameter of the shame should be reduced by 0.5cm. D. The measurement of the exit diameter of the pelvis is not affected by the thickness of the bone. The inner surface should be close to the inner surface of the pubic ischial branch, and the ischial tuberosity should be searched from top to bottom. Once inside the sciatic nodule, the inside of the thumb can not stay on the inner surface of the pubic ischial branch. Therefore, the thumb of the two hands can finally stay at the ischial tuberosity. In the measurement of the diameter, the diameter of the ischial tuberosity not only indicates the length of the transverse diameter of the pelvic outlet, but also the size of the transverse diameter of the middle pelvis.
Other external examinations of the pelvis:
A. Michaelis'rhomboid: The longitudinal diameter of the Mie's diamond-shaped area is normally 10.5cm. If it exceeds this value, it means that the back of the pelvis is too deep; the transverse diameter is 9.4cm. If it is shorter than this value, it means The transverse diameter of the pelvis may be shortened. The normal high value of the upper triangle of the Mie diamond area should be 4~5cm. If the size is 3cm, the pelvic inlet surface is flat (the anteroposterior diameter is shortened). If the upper triangle disappears, it is a serious vitamin D deficiency. Sick pelvis.
B. Pelvic inclination: Anyone who has the following performance should suspect that the pelvis tilt is too large:
a. The maternal abdominal wall is slack, and the uterus is tilted forward to abdomen, which occurs mostly in the mother, and is now rare.
b. The back of the lumbar vertebrae is deep inward and the humerus is upturned.
c. Abdominal examination of the fetal head has a suspicious ride across the phenomenon, that is, the fetal head is higher than the level of the shame, but it can be pushed below the level of the shame by hand pressing, which does not mean that the head basin is not called, but because of the pelvic inclination When it is too large, the fetal head cannot be adapted to the direction of the entrance surface of the pelvis.
d. The pubic symphysis is low. When the woman is lying down, the lower edge of the pubic symphysis is close to the plane of the bed. The examiner often suspects that the pubic symphysis is too long, but it is caused by the excessive pelvic tilt.
2 pelvic measurement: If pelvic stenosis is suspected when measuring outside the pelvis, pelvic internal measurement should be performed in the third trimester or after delivery. The internal measurement should be done by disinfecting the vulva and the vagina after wearing the middle finger of the disinfection glove.
A. Diagonal diameter: It is the distance from the lower edge of the pubic symphysis to the iliac crest. The normal value is 12.5~13cm, and the diagonal diameter minus 1.5cm is equal to the posterior diameter of the pelvic inlet, which is the true binding diameter.
B. Ischial spine diameter: also known as the middle pelvis transverse diameter, this diameter is not easy to measure, the following methods can be used: a. measured with De-Lee pelvis measuring device, but the end of the device is difficult to fix, so it is difficult to check Accurate; b. Some people have suggested that the finger touches one side of the ischial spine in the internal diagnosis and then swept to the other side. The length is estimated by the hand index, but it is not accurate enough. The clinical estimation method can be adopted when the canine spine diameter cannot be accurately understood: a It can be considered that the diameter of the posterior superior iliac spine, that is, the diameter of the Mie diamond, plus 1 cm as the diameter of the ischial spine, b. The easier way is to divide the degree of the ischial spine into 3 to indicate the length of the ischial spine, grade I. : The ischial spine is relatively flat, and the diameter of the ischial spine is longer; Grade II: the ischial spine is moderately prominent, and the ischial spine diameter is also medium length; Grade III: the ischial spine sharply protruding, the ischial spine diameter is short, c. Reference the ischial joint The length of the internode.
C. Middle and posterior pelvic diameter: first determine the appendix joint, then use the internal fingertips to follow the joint upwards, and save the 1cm over the humerus. Here, the junction of the 4th and 5th vertebrae is the post-measure of the measurement. The site is still the lower edge of the pubic symphysis, and the average diameter of the anterior and posterior pelvis is 12.2 cm.
D. Middle pelvic sagittal diameter: This diameter can not be directly measured, but it can be represented by the width of the bottom of the sciatic notch. It can accommodate 3 horizontal fingers as normal. If 2 horizontal fingers indicate that the sagittal diameter is shortened after the pelvis, the notch The width and narrowness of the anus is more accurate, and the vaginal examination is not easy to reach, especially the primipara.
E. Shame joint back angle: This angle should be >156o. If you feel that the back angle of the shame joint is wider, it means the female pelvis. If it is smaller, it is the sputum type or the male pelvis.
In summary, the clinical situation can be determined by the following conditions to determine the stenosis of the middle pelvis: A. sciatic spine grade II or III; B. sciatic notch bottom width <4.5cm (<3 horizontal finger); C. ischial tuberosity The median diameter is 7.5cm, and two or more of them can be diagnosed as middle pelvic stenosis.
Anal finger examination to understand the latter part of the pelvis is often more accurate than the vaginal examination, and simple and easy, actually a method of measurement in the pelvis, the first anal examination after maternal labor should be detailed to understand the latter part of the pelvis The maternal side is placed, the hip joint and the knee joint are flexed and as close as possible to the abdominal wall. The examiner enters the anus to check the following conditions: A. The activity of the appendix joint, the examiner first uses the thumb in the body, and indicates the finger in the anus. The inner tail of the tailbone is shaken to observe whether the appendix joint is active; the appendix joint is fixed, and the tailbone is vertebraized, so that the hook-shaped humerus is formed at the end of the humerus, which can shorten the anterior and posterior diameter of the outlet. B. The inner curvature of the humerus As the joint is ascending, generally the junction of the 2nd and 3rd humerus can be found. According to the curvature of the inner surface of the humerus, the humerus can be used to estimate the straight, shallow, middle or deep arc. If the deep arc type is estimated, the index can be indicated. Leaving the inner surface of the humerus in the direction of the iliac crest, if it can touch the sputum, it can be considered as a deep arc type, the middle arc type humerus is most conducive to childbirth, the shallow arc type is the second, and the straight and deep arc type are not conducive to childbirth. , The anterior and posterior diameters of the pelvis are shortened. The posterior diameter of the entrance surface and the exit of the deep arc type is shortened. C. The sciatic notch is cut. The examiner's indicator retreats to the junction of the 4th and 5th tibia, and then looks to the side. The ischial spine, measuring the notch on the sacral sacral ligament can accommodate a few fingers, if it can accommodate 3 fingers is normal, D. whether the ischial spine is sudden.
Differential diagnosis
Should be identified with a simple flat pelvis.
