Hypoxia of the fetus

Fetal hypopsy is a pathological condition of the fetus due to oxygen starvation, when the necessary oxygen either flows to the fetus in insufficient volumes, or is incorrectly disposed of by its tissues. It is classified as acute when it occurs suddenly in the delivery and as chronic if it accompanies the fetus during development. An independent nosology of fetal hypoxia is not, as it indicates only the only circumstance - the deficit of oxygen required for the full development of the fetus.

Intrauterine hypoxia of the fetus as one of the symptoms accompanies many pathological conditions of the period of pregnancy and childbirth.

Statistically, fetal hypoxia belongs to about 10% of all pregnancies and, accordingly, childbirth.

No biological tissue, whether "young" emerging or "adult" fully functioning, is unable to exist without oxygen. It is necessary for the embryo and the fetus, and only for the child who has come into the world. The fetus in different periods of pre-natal life receives the oxygen necessary for development from different sources.

In the first two weeks, when an intensive division of a fertilized egg occurs, it does not have a circulatory system, and the cells of the outer layer of the fetal egg serve as the source of nutrition for the embryo.

At the end of the 10-day period, the fetal egg in the endometrium begins to actively implant into its thickness. This helps specifically synthesized enzymes that can dissolve the mucous layer, eventually forming a blood-filled cavity, where the future embryo is plunged.

From the 8th to the 16th week, the cells of the envelope surrounding the fetal egg actively divide, forming a kind of "villi" - outgrowths with cavities inside, the surrounding blood vessels grow into them - the placenta is formed.

After 4 months, the placental circulation begins to function properly and begins to deliver oxygen to the fetus. The placenta saturates the incoming blood with oxygen, then transports it to the vein of the umbilical cord, and from there to the fetal liver and its heart, which distributes blood to all tissues and organs of the unborn child by special connections - shunts. Fetal lungs in utero in this process of participation do not accept, since they become full-fledged only at the end of pregnancy.

The first breath the child makes after birth, then his lungs are "straightened" due to the incoming air. From this moment the blood begins to be redirected to the children's lungs, being saturated there with oxygen and feeding all the tissues.

Thus, the placenta belongs to the predominant role in oxygen supply to the fetal tissues, therefore, intrauterine fetal hypoxia is more often associated with abnormalities in its structure or functioning. In turn, placental pathology is almost always due to unhealthy conditions on the part of the mother's body. Infections( especially chronic), iron deficiency anemia, endocrine pathologies, cardiovascular ailments and many other conditions significantly impair placental blood flow and provoke oxygen deficiency in the fetal tissues.

A small oxygen deficit in fetal tissue can compensate, but pronounced oxygen starvation always leads to negative consequences. Depending on the ability of the fetus to adapt to hypoxia without significant damage, hypoxia is classified into three degrees: compensated( first), partially compensated( second) and heaviest-decompensated, third degree. The precise determination of the degree of hypoxia of the fetus makes it possible to assess its severity and to develop adequate therapy tactics.

How to determine the fetal hypoxia of ?First of all, the unfortunate in a fetal state can be suspected by the pregnant woman herself. In conditions of hypoxia, the fetus is uncomfortable, so he begins to behave restlessly, reflexively trying to find such a position in the uterine cavity at which he will feel better, that is, begins to move intensively. Clinically, the pregnant woman feels this in the form of excessive motor activity( "stirring") of the fetus. However, it should be noted that the intensification of fetal movements during hypoxia is noted only in the initial stage, and with hypoxia of the second and third degree the fetus becomes inactive, then ceases altogether. The calculation of the number of movements of the fetus according to the technique suggested by the expert helps to suspect hypoxia.

Reliably it allows to diagnose a combination of several techniques, namely:

- Listening to the heartbeat of the fetus. Deficiency of oxygen causes the fetal heart to contract more intensively to "pump" more blood and to extract from it, respectively, more oxygen than necessary. After 18-20 weeks of pregnancy, the fetal heart beats at a frequency of 140-160 beats per minute.

- Cardiotocography( CTG).It allows simultaneously to measure the frequency of contractions of the uterus and fetal heart rate.

- Doppler. Helps to study blood flow in the vessels of the uterine wall and fetus.

- Ultrasound scanning. The pronounced hypoxia of the fetus may be associated with structural changes in placental tissues, fetal pathology and changes in the normal volume of the amniotic fluid. These changes are well visualized during ultrasound.

- Amnioscopy. Visual assessment of amniotic fluid( number, color, transparency) without compromising the integrity of the amniotic membrane.

Sometimes the diagnosis of fetal hypoxia requires additional measures, for example, hormonal studies.

Treatment of fetal hypoxia in isolation from the cause of its appearance is not carried out. The prognosis of pathology depends both on the degree of hypoxia, and on the timely diagnosis.

Causes of fetal hypoxia

It can be said that a potential threat of fetal hypoxia is present in every pregnant woman. However, it does not always develop even among those who have a high risk of its occurrence. Predicting how the organism of the pregnant woman will behave during the long months is very difficult, therefore the specialist preliminarily calculates all the risks of complications and tries to prevent them. Conclusions like "threatened by intrauterine fetal hypoxia", "threat of fetal hypoxia", often appearing in intermediate diagnoses, should not frighten the pregnant woman, as they only mean that the doctor has identified a provoking factor, and will try to compensate him.

It should be noted that it is impossible to list all possible causes provoking hypoxia of the fetus. This condition does not just have many reasons, it can also appear against the background of a seemingly successful course of pregnancy. Conditionally all the factors provoking hypoxia can be classified into those that the pregnant woman possesses;Which realizes the system of blood circulation of the "fetus-placenta", as well as the pathology of the development of the fetus.

The prerequisites for the violation of the oxygen saturation of the fetal tissues are created even by a normally proceeding pregnancy:

- Pregnancy assumes an increased stress on the cardiovascular system of the mother. The volume of circulating blood increases by 30%, because it should "suffice" and the fetus, and in order to "pump it out", the heart increases the number of cuts, that is, it begins to work at the limit.

- To prevent pregnancy prematurely, the ovaries( yellow body) and then the placenta synthesize the hormone progesterone. Under its influence, the venous walls become less elastic.

- The growing uterus lifts the diaphragm, thereby changing the intra-abdominal pressure, which affects the blood flow.

- As the uterus grows, it presses and deforms the veins of the small pelvis, making it difficult for blood to move along them. With multiple pregnancies, this factor provokes hypoxia in fruits more often than others.

These changes increase the burden on the heart and vessels of the pregnant, but are physiologically acceptable and do not lead to complications. However, if the pregnant woman has chronic cardiovascular pathologies( varicose, myocarditis, vascular and heart defects), such a load can provoke an adaptive breakdown.

Among pathological conditions, hypoxia often provokes iron deficiency( anemia).Iron is involved in the transport of oxygen to tissues, if it becomes small - blood is saturated with oxygen is not enough.

The risk of fetal hypoxia increases if the pregnant woman has endocrine pathologies( diabetes mellitus, thyroid dysfunction) or respiratory system diseases( bronchial asthma).

To overestimate the impact of stressful situations and complex psycho-emotional situation on the course of pregnancy is impossible. Strong emotions provoke the release of the "stress hormone" - cortisol, it spasms the walls of any vessels, including placental. In addition to hypoxia, stress provokes abnormal uterine contractions, which is fraught with untimely termination of pregnancy.

Another negative factor affecting the state of blood vessels in the "fetus - mother" system is smoking. With the participation of nicotine in the placental vessels formed microthrombi, and the blood flow changes the parameters to pathological.

The most common cause of impaired blood flow in the placenta is its infection. At the sources of infectious inflammation there may be viruses, fungi, cocci flora. Under the influence of infection in the tissues of the placenta, edema develops, the walls of the vessels are damaged, the viscosity of the blood changes.

Infection can be localized not only in the placenta zone. Sometimes it is able to overcome the protective "barrier" of the placenta and penetrate the fetus. Infection of the fetus, accustomed to a sterile habitat, provokes serious consequences right up to fetal death.

Sometimes intrauterine hypoxia provokes an abnormal location of the placenta when it is attached to the uterine wall at a site that is worse than the bloodstream. More often this happens in the presence of abnormalities of the uterus.

Thus, intrauterine fetal hypoxia can accompany many pathological conditions.

Symptoms and signs of fetal hypoxia

At different times of gestation, hypoxia affects the developing fetus in different ways. If it appears early, it can slow the formation of the embryo, and in the last trimester its effect is directed to the fetal nervous system, its development and adaptation mechanisms.

Symptoms of fetal hypoxia depend on the degree of impaired blood flow to the placenta and, accordingly, the fetus. To characterize the degree of hypoxia of the fetus, two important clinical criteria are used: the intensity of the fetal movement and the frequency of its cardiac contractions.

• 1 degree of hypoxia is characterized as compensated, that is eliminated by the efforts of the maternal organism, when the stirring and palpitation of the fetus only increase occasionally, do not lead to complications.

• Level 2 already has a subcompensated character, when the risk of disruption of adaptation mechanisms increases.

• 3-degree intrauterine hypoxia is referred to as decompensated, which means that the fetus is not able to function normally under conditions of severe oxygen deficiency.

To determine the extent of the effect of hypoxia on the fetus, the blood flow in the placenta is studied, the fetal heart rate is measured.

Sometimes experts classify fetal hypoxia not by the duration of the pathological factor, but by the severity of clinical manifestations. Then the terms "threatening hypoxia" or "started hypoxia" are used.

The threat of hypoxia is said if there are no obvious signs of oxygen deficiency, but there are prerequisites for its occurrence. This situation is provoked by the pathology of the mother or changes in the placenta. Threatening hypoxia can pass into the started and even chronic, but often with well developed adaptive mechanisms remains only at the stage of probability.

If against the background of well-being the fetus begins to register the first signs of oxygen deficiency, hypoxia is considered to have begun.

How to determine fetal hypoxia? Often concerned about the information she read and the stories of girlfriends, pregnant women ask this question to specialists. Sometimes, if the risk of developing pathological hypoxia is low, the pregnant woman is taught how to determine the fetal hypoxia by the number of his movements. The methodology is not very accurate, because it is based on subjective sensations. The pregnant woman is offered to take a comfortable pose( preferably on her side) and listen to the behavior of the baby, counting the number of his movements. As a rule, for an hour of stirring are felt at least 10 times, and if there are less of them - it is necessary to undergo an additional examination.

Acute fetal hypoxia

Fetal hypoxia is more often diagnosed in childbirth, less often it is detected during pregnancy. The most unfavorable is the situation when both forms of hypoxia, acute and chronic, are combined.

Acute hypoxia appears suddenly, develops rapidly and can kill the fetus very quickly. A similar condition is more common in childbirth, but it can also occur before they begin.

Causes of acute hypoxia are often the wrong location of the umbilical cord when it is tightly wrapped around the child many times. This can happen in childbirth, and when pregnancy is only born. Fetal vessels are pinched, and oxygen stops flowing to the fetus. Prolonged oxygen starvation leads to the death of brain cells of the fetus, so the situation requires an emergency solution.

Also acute fetal hypoxia is diagnosed in the presence of nodes on the umbilical cord, placental abruption, uterine rupture and other serious pathologies.

Complicated birth can cause severe fetal hypoxia. In childbirth, it is often called asphyxia( suffocation).She appears on the background:

- The prolapse of the umbilical cord and / or its clamping, the code of blood through the umbilical vessels suddenly stops feeding the baby.

- Placenta prognosis when it is abnormally low and partially prevents the birth of the fetus.

- Abnormal labor, especially when the child's head is "standing" in the birth canal because of weak attempts.

Diagnosis of fetal hypoxia in acute form does not cause difficulties.

Clinical signs of acute hypoxia:

- Rapid heartbeat of the child, alternating with its slowdown until complete cardiac arrest.

- Abnormal motor activity( wiggling) of the fetus: first it starts to move too intensively, then the number of movements becomes minimal.

Chronic hypoxia of the fetus

The chronic form of hypoxia is certainly a serious condition, but unlike acute, it is most favorable, as it develops gradually, it can be detected in the early stages and with timely due treatment is well-managed. Severe forms of chronic hypoxia occur infrequently.

The manifestations of intrauterine hypoxia largely depend on the processes occurring in the placenta, namely, in its bloodstream. If the placental circulation is disturbed due to diseases of the mother or fetus, that is, it has a secondary character, first there will be signs of these diseases( renal failure, severe anemia and others).

If intrauterine hypoxia is caused by a violation of the placental blood flow of a primary nature, a pregnant woman can not for a long time feel changes in the state of the fetus and her, respectively.

The clinical situation in chronic hypoxia, in contrast to acute oxygen starvation, is characterized by a gradual, prolonged increase in signs of oxygen deficiency in the developing fetus.

The first symptoms are changes in the habitual mode of motor activity of the fetus and the increase in heart beat.

As a rule, most pregnant women sensitively catch the first signs of ill-being in the behavior of the fetus. First of all - when his motor activity becomes unusual. Independently, the fetal movement of a woman is felt after the 5th month( in re-giving birth - a little earlier) of pregnancy. The number of movements of the fetus and their intensity over the day are distributed unevenly, so the only increase in motor activity for diagnosis is of little significance. Diagnostically important is not the amount of fetal movements felt for one "session", but the alternation of episodes with the definition of the gap between them.

Usually the fetus moves more intensively in the evening, and also at night, it continues to move no more than two minutes( in one episode) with a one- or two-hour interval. Conditionally, one or two perturbations are taken as the norm for an hour. Self-diagnosis in this case can lead to incorrect conclusions, therefore it is necessary to get recommendations on the correct calculation by a specialist.

No less important sign of hypoxia is the frequency of fetal heart contractions. It is measured at each scheduled visit to a pregnant woman.

So, if a pregnant woman experiences changes in the habitual motor activity of the fetus, and the doctor discovers a change in the number of his heartbeats, a more detailed diagnosis of fetal hypoxia is needed.

Fetal hypoxia treatment

Fetal hypoxia is isolated from its cause to be treated is useless. Therefore, first establish the cause, and then determined with treatment. Acute hypoxia always implies emergency measures, so treatment is conducted according to a specific situation, when the degree of threat to the child is assessed. Unfortunately, in most cases, an acute shortage of oxygen requires an urgent termination of pregnancy, that is, emergency delivery( caesarean section).

The treatment of chronic hypoxia takes into account its degree and duration. There is a direct relationship between the duration of hypoxia and the severity of its consequences. Formation of the fetus in conditions of prolonged oxygen deficiency depletes its adaptive reserves and inevitably provokes deviations in normal development. It is also necessary to take into account the presence of mother pathology.

A clear algorithm for the therapy of chronic intrauterine hypoxia does not exist, because in each individual case it is unique and has a huge number of reasons. The general principles of therapy are:

- creating comfortable conditions( nutrition, regimen, proper physical activity of the mother) of bearing;

- control and necessary correction of blood clotting changes;

- treatment of chronic diseases of a pregnant woman, including infectious origin;

- medical improvement of placental blood flow and metabolic processes in the "fetus-mother" system.

Unfortunately, not a single drug that cures placental insufficiency exists. If the placenta already has abnormal blood supply, it can only be maintained at an acceptable level for fetal development.

Unfortunately, pregnant women do not always understand that even with good health and no negative symptoms, the fetus may not be as well-off. The first signs of fetal hypoxia are more often noted only by qualified examination, which means the need to fulfill all medical recommendations, including preventive treatment.

Consequences of fetal hypoxia for a child

It should be explained that a child is referred to as a "fetus" if it is still in the uterine cavity. After the birth of the fetus is called a child.

Fetal hypoxia inevitably affects the baby after birth. Deficiency of oxygen in the period of intensive development of the fetus affects the degree of maturation of organs and tissues, the immune, nervous system. If hypoxia is diagnosed timely and timely "helped" the fetus medication, its consequences for the child will be minimal, or they will not manifest at all.

More often chronic hypoxia provokes:

- hypotrophy, that is, a decrease in growth and weight, as a rule, the degree of hypotrophy is correlated with the degree of intrauterine hypoxia;

- weak immunity and, as a result, increased susceptibility to infectious ailments;

- violations in the system of thermoregulation, when the child has temperature fluctuations;

- different degrees of anemia.

In chronic hypoxia, the brain tissue of the fetus is "choked", so at a later age, when the child begins to socialize, he may have attention disorders, increased excitability and excessive activity.

The consequences of acute hypoxia for a child can be severe. Most often diagnosed:

- pneumonia after inhalation of meconium( original feces) in the womb;

- the death of a site or the entire intestine on the background of its ischemia;

- increased risk of cerebral palsy( cerebral palsy);

- damage to the tissues of the nervous system, including to whom.

Despite the possibility of such serious consequences, more often the majority of cases of hypoxia for the child are not dangerous. If the child safely survives the first month, the negative consequences for him are not diagnosed.

Consequences of fetal hypoxia in childbirth

In childbirth, the fetus is particularly vulnerable to oxygen deficiency. Hypoxia in labor is always acute and can provoke fetal death if it does not stop in time.

Provoke hypoxia in childbirth:

- late severe toxicoses: preeclampsia and eclampsia;

- shock or heart failure;

- placental abruption or her presentation with bleeding;

- severe anemia in the mother;

- pathology of the umbilical cord( knot, crook, thrombus and others);

- too long birth.

More often than other hypoxia in childbirth provokes too intensive reduction of the uterine wall, especially when introducing stimulants such as oxytocin. If, during childbirth, the fetus remains without adequate blood supply for a long time( especially for brain cells), it can die, therefore, in each specific situation, the decision on the method of conducting labor is taken individually. However, with a high threat to the life of the fetus, which is almost always present in acute hypoxia, it is reasonable not to expose it to further risk and immediately extract it from the womb.

Any acute fetal hypoxia in childbirth "rooted" in the period of gestation, when for the first time its prerequisites begin to form. Therefore, more often, if the pregnant woman conscientiously treats her condition, the appearance of acute hypoxia in childbirth can be prevented.

Prevention of fetal hypoxia

During pregnancy and the risk of its complications, including, significantly affects the health of the mother. Ideally, the situation is considered when a woman planning to become pregnant appeals to a specialist to assess her condition and predict the course of a potential pregnancy. This, unfortunately, happens rarely. And although the woman is addressed to the doctor with such a purpose already being pregnant, the specialist has time to study the mother's body if the turnout is early.

All registered pregnant women are made individual plans, which indicate the potential risks. It is during this period that a conclusion may arise about the possibility of developing hypoxia.

Treatment of pathologies of a pregnant woman should always be carried out, regardless of the condition of the fetus. The treatment of infectious and inflammatory processes of the genital area, anemia. In the case of extragenital pathology( diabetes mellitus, thyroid pathology, cardiovascular ailments and others), adjacent specialists are involved in treatment.

The most effective prevention of fetal hypoxia is a regular visit to a specialist and conscientious implementation of their recommendations.

It is worthwhile to understand that hypoxia can be prevented by following simple rules:

- visit a specialist at an early( up to 12 weeks) time and go through all the stages of the examination;

- follow the recommended schedule of visits to the doctor, usually - once a month at the beginning and twice - in the last two terms;

- adhere to the recommended diet and have a lot of rest;

- avoid stress and infection;

- to take all the recommended drugs, including vitamins;

- to monitor existing chronic ailments with a therapist.