Contracted pelvis

Contracted pelvis

To the XVI century it was believed that the bones of the pelvis during birth diverge, and the fetus is born, pushing his legs in the bottom of the uterus. In 1543 the anatomist Vesalius proved that the bones of the pelvis are connected still, and doctors have turned their attention to the problem of a narrow pelvis.

The anomalies of the pelvis bone are among the most frequent causes of the normal flow of labor. Despite the fact that the recent gross distortion of the pelvis and the high degree of constriction are rare, the problem of a narrow pelvis has not lost its relevance today — due to the acceleration and the increase in body weight of newborns.

Causes

Causes contraction or deformation of the pelvis may be:

  • congenital anomalies of the pelvis,
  • malnutrition in childhood,
  • disease experienced in childhood: rickets, polio, etc.
  • disease or injury pelvic bones and joints: fractures, tumors, tuberculosis.
  • deformities of the spine (kyphosis, scoliosis, deformity tailbone).
  • one of the factors in the formation of the pelvis is poperechnosuzhennogo acceleration, resulting in puberty to a rapid increase in body length with lagging growth of the transverse dimensions.

Forms

Anatomically narrow is a basin in which at least one of the main dimensions (see below) is less than the normal-1,5-2 cm or more.

However, the most important are not the size of the pelvis, and the ratio of the size to the size of the fetal head. If the head of the fetus is small, even for some narrowing of the discrepancy between the pelvis and the head of the child is born, and can not be, and birth are made naturally without any complications. In such cases, the pelvis is anatomically tapered functionally sufficient.

Complications may arise in the delivery of normal size and pelvis — in those cases when the fetal head is more than pelvic ring. In such cases, the promotion of the head through the birth canal suspended: the pelvis is almost narrow, functionally inadequate. Therefore, there is such a thing asclinically (or functional) narrow pelvis. Obstructed — the indication for caesarean section in labor.

True anatomically narrow pelvis occurs in5-7% Of Women. The diagnosis of clinically narrow pelvis set only in labor for a set of attributes that identify the disparity of the pelvis and head. This type of pathology found in1-2% Of all births.

How to measure the pelvis?

Contracted pelvis

In obstetrics study of the pelvis is very important because its structure and size are critical to the course and outcome of labor. The presence of a normal pelvis is one of the main conditions for the proper flow of labor.

Abnormalities in the structure of the pelvis, especially the reduction of its size, make it difficult for a natural birth, and, at times, insurmountable obstacles for them. Therefore, when production of the pregnant woman on account of the antenatal clinic and on admission to the hospital in addition to other surveys conducted necessarily external dimensions of the pelvis. Knowing the shape and size of the pelvis, it is possible to predict the course of labor, possible complications, make a decision on the admissibility of spontaneous delivery.

The study includes a pelvic examination, the feeling of bones and determining the size of the pelvis.

In a standing position examine the so-called lumbosacral rhombus, or diamond Michaelis (Fig. 1). Normally, the vertical size a diamond in the middle is 11 cm, the cross — 10 cm in violation of the structure of the pelvis lumbosacral a diamond is expressed clearly, the shape and size of its changed.

After feeling the pelvic bones hold its measurement using tazomera (see Fig. 2a and b).

Contracted pelvis

In obstetrics study of the pelvis is very important because its structure and size are critical to the course and outcome of labor. The presence of a normal pelvis is one of the main conditions for the proper flow of labor.

Abnormalities in the structure of the pelvis, especially the reduction of its size, make it difficult for a natural birth, and, at times, insurmountable obstacles for them. Therefore, when production of the pregnant woman on account of the antenatal clinic and on admission to the hospital in addition to other surveys conducted necessarily external dimensions of the pelvis. Knowing the shape and size of the pelvis, it is possible to predict the course of labor, possible complications, make a decision on the admissibility of spontaneous delivery.

The study includes a pelvic examination, the feeling of bones and determining the size of the pelvis.

In a standing position examine the so-called lumbosacral rhombus, or diamond Michaelis (Fig. 1). Normally, the vertical size a diamond in the middle is 11 cm, the cross — 10 cm in violation of the structure of the pelvis lumbosacral a diamond is expressed clearly, the shape and size of its changed.

After feeling the pelvic bones hold its measurement using tazomera (see Fig. 2a and b).

Contracted pelvis

Main dimensions of the pelvis:

  • Mezhostny size. The distance between the upper, anterior iliac awns ([1] in Fig. 2a) in power rate 25-26 see
  • The distance between the most distant points of the iliac crests [2] (Figure 2a.) — 28-29 cm between the greater trochanter [3] (Figure 2a.) — 30-31 see
  • Outdoor conjugate — the distance between nadkresttsovoy fossa (upper corner of the diamond Michaelis), and the upper edge of the pubic symphysis (Fig. 2b) — 20-21 see

Contracted pelvis

The first two dimensions are measured at the position of women lying on your back with arms and legs pushed together, and the third dimension is measured and shifted slightly bent legs. Outdoor conjugate is measured in the position of women lying on its side with a bent at the hip and knee joints and the underlying leg stretched overlying.

Some dimensions of the pelvis detected during vaginal examination.

In determining the size of the pelvis is necessary to take into account the thickness of its bones, it is judged by the value of so-called index Solovyov — the circumference of the wrist joint. The average value of the index of 14 cm If the index is greater than 14 cm Solovyov, it can be assumed that the bones of the pelvis and the massive size of the pelvis less than expected.

If you want to get more data on the size of the pelvis, according to its magnitude of the fetal head, bone deformities and their compounds, conduct X-ray of the pelvis. But it is made only on the strict condition. About the size of the pelvis and head according to its magnitude can be judged by the results of the ultrasound.

The influence of a narrow pelvis during pregnancy and childbirth

The adverse effect of a narrowed pelvis during pregnancy affects only in the last months of her. Fetal head does not fall into the small pelvis, growing uterus rises significantly and makes breathing difficult. Therefore, at the end of early pregnancy shortness of breath, it is more pronounced than in a normal pregnancy pelvis.

In addition, a narrow pelvis often leads to an incorrect position of the fetus — oblique or transverse. In 25% of pregnant women with transverse or oblique position of the fetus is usually a more or less severe narrowing of the pelvis. Breech fetus in pregnant women with reduced pelvis occurs three times more often than women in labor with a normal pelvis.

The management of pregnancy and childbirth with a narrow pelvis

Pregnant women with narrow hips are at high risk for developing complications, and women's clinic should be in a special account. Should be timely detection of fetal anomalies of position and other complications. It is important to accurately determine the due date to prevent pregnancy perenashivanie that with a narrow pelvis is particularly unfavorable. For1-2 weeks before delivery to pregnant women with narrow hips Hospitalization is recommended in the department of pathology for diagnosis and choice of a rational method of delivery.

Current delivery by narrow pelvis depends on pelvic contraction. With slight narrowing, medium and small size of the fetus may be birth vaginally. During labor, the doctor carefully monitors the function of vital organs, the nature of
tribal forces, the fetus and the degree of compliance of the fetal head and pelvis mothers and if necessary, promptly decide on the cesarean section.

Absolute indication for caesarean section is:

  • anatomically narrow pelvis III-IV the degree of narrowing;
  • the presence of bone tumors in the small pelvis, obstructed labor;
  • abrupt deformation of the pelvis as a result of trauma or disease;
  • breaks the pubic symphysis of the pelvis or other damage caused in the course of the previous birth.

In addition, the indication for caesarean section is a combination of a narrow pelvis:

  • the large size of the fetus,
  • perenashivanie pregnancy
  • chronic fetal hypoxia,
  • breech,
  • genital malformations,
  • uterine scar after cesarean delivery and other operations,
  • indicating the presence of infertility in the past,
  • nulliparous age older than 30 years, etc.

Caesarean section is performed at the end of pregnancy to the beginning or from the onset of labor.

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