Many women, having learned about their new position, begin to worry about their physiology. In particular, we are talking about the size of the pelvis, since this largely determines how the pregnancy will proceed. Its narrowed form almost always leads to various complications during childbirth. At the very first visit to the antenatal clinic, where every woman, in the event of a successful conception, is registered, attention is paid to this moment. And in some cases, the expectant mother may be "happy" with the diagnosis - a narrow pelvis during pregnancy.
But what is it, can there be any consequences, and how then do the births proceed? All these issues worry many women. Well, let's try to figure it all out.
What should be understood by a narrow basin?
The pelvis of any woman is the formation of a dense inextensible ring of bone structures. A child passes through him: first his head, then his body. In this case, the cartilage tissue softens, which allows the ring to grow.
The female pelvis consists of 4 bones:
- 2 pelvic, which are formed by the iliac, pubic and sciatic bones.
- Sacrum.
- Coccyx.
All of them are interconnected by means of cartilage and ligaments. The female pelvis is different from the male: it is wider, more voluminous, but at the same time it has less depth. And if the normal parameters (we will touch on them a little later) of the pelvis in no way affect the course of labor, then with its deviations there can be serious complications.
In medical practice, there are two main types of narrow pelvis:
- Anatomical - a decrease in one or more parameters by 20 mm or slightly more.
- Clinical - here we have in mind the mismatch of the child’s head and the woman’s bone ring.
At the same time, the functionality of the female pelvis may not always be impaired. For example, a child is small in comparison with a narrow basin. It is the same and vice versa - if the pelvis has normal indicators, and the fetus is quite large. Here you can also talk about a clinically narrow pelvis.
Norm indicators
Now let's touch on the normal parameters of the female pelvis. All measurements are carried out using a special instrument - tazomer. The following sizes are evaluated:
- Normally, the length between the anterior upper corners of the ilium is 25-26 cm.
- The distance between the farthest sections of the iliac crests should be from 28 to 29 cm.
- The distance between the large trochanter of both thighs is 30-31 cm.
- The distance from the upper part of the symphysis to the supra-sacral fossa is 20-21 cm.
The lumbosacral rhombus (Michaelis rhombus) has the following norm indicators: diagonally - 100 mm, and vertically - 110 mm.
Moreover, if the asymmetry is expressed in the Michaelis rhombus, or deviations of the pelvic dimensions are observed to a smaller side, this indicates that the bones differ in irregular structure.
Classification of the pelvic bones
According to experts, there are many varieties of a narrowed pelvis. And often in obstetric literature a classification is reflected, which is based on morphological and technological features. According to them, the pelvis can be:
- Gynecoid. It is considered a normal type and occurs in 55% of all cases. With such a physique, a woman with such a basin has a thin neck and waist, while the hips are wide. As for weight and height, everything is within normal limits.
- Android. This type is found a little less often - 20% and is typical for most men. Nevertheless, such a basin can also be found in women with a male physique: broad shoulders, narrow hips, a thick neck and an unexpressed waist.
- Anthropoid. It is already 22%. In such a basin, the direct size of the entrance is increased, the transverse size is even larger. Such women are distinguished by high growth and leanness. They have broad shoulders, and the waist and hips, on the contrary, are narrow, the legs are thin and elongated.
- Platypeloid is the rarest type of pelvis found in only 3% of women. They are tall, thin, musculature is underdeveloped, and skin elasticity is markedly reduced.
As for the form of the pelvis in women, it can also be very different. Of all the most common are:
- Generally constricted or ORST. The most common form of the pelvis is 40-50% of all cases.
- Cross-narrowed or Robert's basin.
- Flat. In turn, it is divided into several varieties: just a flat basin, flat-rachitic, a basin in which a wide part of the cavity is reduced.
At the same time, there are those forms that are extremely rare:
- skewed;
- squinted;
- general flat;
- funnel-shaped;
- kyphotic;
- spondylolistetic;
- osteomalytic;
- assimilation.
Now it is worth touching on the degree of narrowing of the pelvis in women, of whom there are 4:
- 1st degree - conjugates are 9-11 cm in size.
- 2nd - conjugate sizes 7.5-8.9 cm.
- 3rd - dimensions conjugates 6.5-7.4 cm.
- 4th — conjugate sizes less than 6 cm (absolutely narrow basin).
As many obstetricians note, mainly I and II degrees of narrowing of the pelvis.
Causes of a narrow pelvis
Most women, if a narrow pelvis is revealed in them, consider this an individual feature of their bone structure, acquired from parents. In fact, this is not entirely true, although heredity also makes sense not to exclude. But as medical practice shows, in 90% of cases, this problem is more likely acquired than congenital.
The bone structure of the anatomically narrow pelvis is influenced by a variety of factors, and therefore it is quite difficult to take the necessary preventive measures. These include:
- Diseases of an infectious nature, transferred in childhood.
- A poor diet, in which an insufficient amount of the necessary micronutrients enters the body.
- Manifestations of frequent vitamin deficiency at a very young age.
- Hormonal imbalance in the body in adolescence.
- Diseases that affect the bone structure, previously transferred, such as rickets, poliomyelitis, tuberculosis.
- Congenital deformity of the skeleton.
- In the past, there were fractures or bruises of the pelvic bones.
- Tumor in the pelvic area.
- The development of acceleration, when a girl grows only in height, while in width she remains narrow.
The causes listed above relate to a transversely narrow pelvis during pregnancy or some other form of anatomical nature. But there are still cases of its clinical form. About it further.
The clinical form of the pelvis and its causes
The clinical form of the narrow pelvis can be detected only during childbirth, since it does not depend on its physical parameters. It is diagnosed only in cases where the child's head exceeds the size of the bone ring. Typically, the clinical form can be diagnosed even in the absence of a narrow anatomical pelvis.
A diagnosis of this kind also has certain reasons:
- Long term bearing a child.
- Large fruit.
- Neoplasms in the uterus.
- The baby's head does not fit into the pelvis correctly.
- Dropsy of the brain in the fetus.
- Any deviation in the development of the fetus in the womb.
Regardless of the type and parameters of the narrow pelvis during pregnancy, this is in any case a rather serious pathology. If you ignore this fact, the consequences can be the most serious.
Diagnosis
The probability of a narrow pelvis in a woman should be determined long before the birth of a child, which will allow to avoid all kinds of complications. In this case, during the diagnosis, it is important to pay attention to the anamnesis. That is, it is necessary to find out how the development of the woman in childhood and puberty took place, whether there were any diseases or injuries.
To determine the narrow shape of the pelvis, an external examination is performed with the measurement of the dimensions of the pelvis and the fetus. In addition, other examinations are carried out:
- Ultrasound
- X-ray pelviometry.
The very first question that comes to mind a woman with a narrow pelvis during pregnancy: how to give birth in this case? During the ultrasound examination, it will be noticeable whether the dimensions of the baby's head correspond to the dimensions of the pelvic bones and how exactly it is located. If this is a facial or frontal presentation, then during childbirth, the baby's head needs more space.
X-ray pelvic measurements are carried out only at the end of the III trimester. At this time, all tissues and organs are fully formed in the fetus. This procedure allows you to identify the shape of the bone structure of a woman, as well as determine the size of the fetal head and compliance with their standards.
As soon as the expectant mother is registered in the antenatal clinic, the gynecologist will carry out all the necessary measurements of the pelvis. This is done using a special tool, which in appearance resembles a pair of compasses and has a centimeter scale.
Visual observation
Suspicion of a narrow pelvis during pregnancy may occur before visiting a antenatal clinic. There are visual signs that may indicate a narrow pelvis:
- A woman has brushes of short length - 16 cm or slightly less.
- Small foot sizes.
- In short ladies with a growth of less than 165 cm, spinal curvature, lameness and other gait disorders are clearly visible.
- Previous births in women were complicated.
- Malfunctions of the menstrual cycle.
- Representatives with a male physique.
This is a kind of risk group, which not every woman falls into.
Pregnancy with a narrow pelvis
From the moment when the expectant mother (when she identifies a narrow pelvis) is registered in the antenatal clinic, she is closely monitored by a gynecologist. By the end of the term, and this is about a couple of weeks before the birth of the baby, mom is hospitalized in the antenatal department. Here, the gestational age is clarified, the estimated fetal mass is determined, and other possible complications are identified.
In frequent cases, due to the narrow pelvis of a woman, the fetus takes the wrong position. Often we are talking about pelvic presentation, but there may be other cases: oblique and transverse.
In the last trimester, the expectant mother may herself notice some characteristic manifestations. For example, she has shortness of breath. This is due to the fact that the size of the narrow pelvis during pregnancy does not allow the baby’s head to snuggle up to the entrance to the small pelvic area. In those women who give birth for the first time, the stomach takes on a spiky shape. Multiparous mothers are characterized by a saggy stomach due to the weak abdominal wall.
What can be the complications?
Pregnancy against the background of a woman’s narrow pelvis can occur almost without complications, or there may be a threat of her interruption, regardless of the term. There may also be other complications in the form of gestosis, fetoplacental insufficiency. If the baby has a medium-sized head, then the birth can go smoothly. But often, labor activity occurs with characteristic complications with a woman's narrow pelvis.
Because of this bone anatomy, a woman prematurely leaves the water. Due to untimely opening of the fetal bladder, the baby’s leg or handle drops out, which causes certain complications during childbirth - both the mother and the newborn increase the risk of birth injury. Due to the loops of the umbilical cord, the fetal head may be pinched, resulting in acute hypoxia and even fetal death.
In addition, a narrow pelvis can lead to the fact that the fetal head is in the same plane for a long period of time. As a result of this, the pelvic organs experience quite a long pressure. In turn, this can lead to subsequent tissue necrosis and the formation of vaginal fistulas. And if at the same time labor will be very developed, rupture of the perineum, vulva, vagina, and uterus is not ruled out.
Violations of the birth process often result in postpartum hemorrhages, as well as the development of lohiometers due to poor contractility of the uterus and delays of the lochia.
But which is much more dangerous, childbirth with a narrow pelvis in almost all cases pose a serious threat to the fetus:
- Often a child is born with asphyxia or in a hypoxic state.
- In the fetus, cerebral circulation may be impaired.
- Risk of cranio-spinal injury.
All these and some other complications may require observation by a neurologist, neurosurgeon, or resuscitation treatment, including a long rehabilitation period.
Generic activity
The exact nature of the birth can depend on the anamnestic data, the anatomical shape of the narrow pelvis, its degree, the estimated weight of the baby and other complications. Childbirth can occur naturally, but only with the small size of the child, his correct presentation, and also if the degree of narrowing of the pelvis is insignificant.
Due to the early discharge of amniotic fluid, the cervix opens more slowly. In addition, an infection can enter the cavity of the genital organ, resulting in endometritis, placentitis, or the fetus itself is at risk. The first contractions in this case are characterized by severe pain, and the first labor period lasts quite a long time.
As practice in the field of obstetrics shows, pregnancy and childbirth with a narrow pelvis are accompanied by rare and weak contractions in the first half. And the whole process can drag on for a rather long time, which leads to severe fatigue of the woman in childbirth.
In the second birth period, there may be certain difficulties associated with the advancement of the baby's head. In this case, the pain becomes more intense, and the woman has general fatigue.
The need for caesarean section
Indications for surgical intervention can be absolute and relative. The first cases include the following cases:
- The narrow form of the pelvis III or IV degree.
- Deformation of the pelvis of a woman is pronounced.
- The joints and the pelvic bones themselves are damaged due to previous labor.
- The presence of a tumor in the bones of the pelvis.
Based on the listed symptoms, a child can be born only through cesarean section. Such a procedure is carried out in a planned manner, starting from the time of birth or from the appearance of the first contractions.
Relative indications include the following symptoms:
- Anatomically narrow pelvis of the II degree.
- I degree of a narrow pelvis against the background of other additional factors.
- Big kid.
- Pelvic presentation of the fetus.
- Postponed pregnancy.
- Hypoxia of the fetus.
- A scar on the uterus from a previous labor operation.
- Anomalies of the genitals.
In the presence of these relative factors, a woman can still try to give birth naturally. However, if during the course of labor, the condition of the expectant mother begins to deteriorate, as well as when a serious threat is identified for her and the child, a cesarean section is performed.
Useful Tips
Every pregnant woman, especially with a narrow pelvis, should listen to the advice of a specialist. Only he will be able to give recommendations on how the birth can take place in each case. But only if there is a danger to the child or he risks getting injured, you will have to resort to surgical delivery. And this will be the surest and only right choice.
For any woman, bearing a child is the most pleasant moment in her life. Mom immediately begins to take care of herself and lead a more correct lifestyle. This also applies to those women who have been diagnosed with a narrow pelvis. However, there is no reason for concern here, and the baby can be born quite healthy and full. For this, the main thing is to follow all the doctor's recommendations. Then the entire period of pregnancy will go smoothly, and childbirth will pass without serious complications.
In conclusion
It is worth noting that a narrow pelvis is a fairly common diagnosis. But! Despite this, many women with a similar bone structure could give birth to healthy children without complications. In this regard, one should not be afraid of such a “terrible” diagnosis - a narrow basin. If the degree of the narrow pelvis during pregnancy is not too strong, then childbirth can take place naturally.
Otherwise, a cesarean section will be performed, which will allow the baby to freely appear in the light, and the woman will be able to hug him, becoming a full mother.