Reasons and procedure for conducting a fetal biophysical profile study. Determination of the biophysical profile of the fetus Decoding the biophysical profile of the fetus

Fetal biophysical profiling is used in some clinics as the primary antenatal examination, while in others it is used only when the contractile stress test is positive or inconclusive. For example, the biophysical profile of the fetus is determined in the case of premature rupture of amniotic fluid. With the development of chorioamnionitis, complicating premature rupture of membranes, the biophysical profile of the fetus is rarely satisfactory. In addition, with chorioamnionitis, the reactivity of the stress-free test disappears.

Currently, the so-called fetal biophysical profile is used to assess the intrauterine state of the fetus. Determining the biophysical profile of the fetus to obtain objective information is possible from the beginning of the third trimester of pregnancy.

The concept of “biophysical profile of the fetus” includes data from a non-stress test (with CTG) and indicators determined by ultrasound scanning: fetal respiratory movements, motor activity, fetal tone, volume of amniotic fluid, degree of placental maturity. Each parameter is scored from 0 (pathology) to 2 (normal).

The points are summed up and an indicator of the fetal condition is obtained (Table 11-6).

Table 11-6. Criteria for assessing the biophysical profile of the fetus (A. Vintzileos, 1983)

A score of 8–12 indicates the normal condition of the fetus. A fetal biophysical profile score of 6–7 points indicates a questionable condition of the fetus. A score of 4–5 or less is an indicator of severe fetal hypoxia and a high risk of developing perinatal complications.

The high sensitivity and specificity of the biophysical profile of the fetus is explained by a combination of markers of acute (non-stress test, respiratory movements, motor activity and fetal tone) and chronic (volume of amniotic fluid, degree of placental maturity) impairment of the fetal condition. A reactive non-stress test, even without additional data, is an indicator of the satisfactory condition of the fetus, while in the presence of a non-reactive non-stress test, ultrasound of the remaining biophysical parameters of the fetus is of particular importance.

Determination and assessment of the biophysical profile of the fetus is a non-invasive (external) examination that is a combination of a non-stress test and ultrasound. The results obtained allow us to evaluate the child’s movements of the arms and legs, his muscle tone, respiratory function (the ability to contract the muscles of the chest) and the amount of amniotic fluid that surrounds him. An additional parameter to be determined is the degree of maturity of the placenta.

Reasons for referral for biophysical profile research

In the vast majority of cases, women who have any diseases that can complicate the course of pregnancy are sent to determine the biophysical profile of the fetus. Or those who have developed certain problems during pregnancy that are associated with an increased risk. Among these problems and diseases are the following:

1. Diabetes mellitus, which is treated with insulin
2. Hypertension, which was present before pregnancy, or developed during pregnancy
3. The baby is too small for his age and is gaining weight slowly
4. If you have (high or low water)
5. If the child’s physical activity is too low
6. Post-term pregnancy. If the expected date of birth has arrived (usually after), but labor has not yet begun
7. During your last pregnancy, you experienced... Or the cause was the same problem that is present during real pregnancy
8. If the non-stress test showed poor results (turned out to be non-reactive)
9. As a result of any other reasons that cannot be ignored.

Assessment of the biophysical profile in points. What do they mean?

Determining the biophysical profile of the fetus allows you to assess its general condition and understand whether it receives enough oxygen. Each indicator is assigned a score of 0, 1 or 2. There are 5 such indicators in total: motor activity, muscle tone, respiratory contractions, amount of amniotic fluid and non-stress test. Sometimes a sixth indicator is added to the overall assessment - the degree of maturity of the placenta.

How are various biophysical profile indicators assessed?

Physical activity. Three or more obvious fetal movements within 30 minutes - score 2. One or two movements - score 1. No movements within a given time interval - 0 points.

Muscle tone. If a child, within 30 minutes, performs at least 1 flexion of the spine and limbs returning to their original state, a score of 2 is given. If a child performs at least one extension-flexion of only the spine or only the limbs - score 1 point. If his limbs remain in an extended position, the score is 0 points.

Breathing contractions. One or more respiratory episodes occurring within 30 minutes and lasting for 60 seconds - 2 points. One or more breathing movements within 30 minutes, lasting 30-60 seconds - 1 point. If during 30 minutes of observation there were no respiratory movements or lasted less than 30 seconds, the score was 0.

The amount of amniotic fluid. If the amniotic fluid is clearly visible inside the uterus and the vertical thickness of the free area of ​​water is at least 2 cm, the score is 2 points. If the thickness of the free area of ​​water is 1-2cm, the score is 1. If the close arrangement of parts of the child’s body is visible and the size of the free area of ​​water is less than 1cm, then a score of 0 is given.

Non-stress test. We have already talked about the positive and negative results of the non-stress test on the "" page.

Degree of maturity of the placenta. This additional parameter may also be taken into account when studying the biophysical profile of the fetus. If the degree of maturity is 0, I or II, a score of 2 is given. If the placenta is located in such a way that its complete examination is difficult, then a score of 1 is given. If the degree of maturity of the placenta is III, a score of 0 is given.

The total score for all indicators can range from 0 to 10 points (if the degree of maturity of the placenta is also assessed, then the maximum score is 12 points). If the sum of points is 8 or more, then the baby’s condition is considered normal. A score of 6-7 points indicates the possible presence of some problems, and if the overall score is less than 6 points, then this is an alarming indicator that can signal serious hypoxia and a high risk of complications.

If all ultrasound indicators are normal, the doctor will move on to assessing the baby’s heartbeat. It is also important to know that if the amniotic fluid volume score is 0, then the child may need additional examination. In some cases, the doctor may recommend that you induce labor, even if everything else is fine.

Depending on the final summary assessment and other factors (gestational age, presence or absence of complications, etc.), the doctor may additionally recommend that you undergo other tests and examinations. In some cases, he may recommend stimulating labor by inducing artificial labor or, if the baby is in any danger, directing you to a caesarean section.

Since the determination of the biophysical profile of the fetus consists of a detailed ultrasound examination and a non-stress test, the duration of the examination can be more than an hour.

The maturation of the nervous system leads to the formation in the fetus of a clear change in periods of sleep and wakefulness, which become distinguishable by the 20th week of pregnancy. After this period, the gynecologist can send the woman to study the biophysical profile of the fetus. In what cases is this test carried out and how to decipher it?

What is the biophysical profile of the fetus?

Fetal biophysical profile (FBP) is a summary assessment of CTG examination and ultrasound monitoring of the intrauterine state of the child.

Ultrasound examination is carried out in real time. During an ultrasound, the amount of amniotic fluid and various types of baby movements are assessed.

The CTG method records fetal heart rate variability. Transcript from a cardiologist.

Indications for research

Determination of the biophysical profile of the fetus is carried out in the third trimester of pregnancy. It is prescribed to women with post-term pregnancy, as well as in later stages if there are the following indications:

• intrauterine growth retardation according to ultrasound data;
• diabetes mellitus, gestational diabetes, arterial hypertension and other chronic diseases affecting the course of pregnancy;
• oligohydramnios or polyhydramnios;
• decreased activity of the child;
• post-term pregnancy;
• a history of late miscarriages of unknown etiology.

Determination of the biophysical profile of the fetus

By week 28, the fetus has fully formed a system of reactions to external influences. From now on, the biophysical profile, also called the fetal well-being test, becomes informative.

Determining the BPP takes at least 40 minutes. During this time, the pregnant woman undergoes cardiotocography and ultrasound. To stimulate the child a little, you need to eat before the procedure.

For BPP, the results of a non-stress test are required. The norm is the acceleration of the number of heart beats after the child’s own movements. If there are signs of cardiac depression, the heart rate will remain unchanged or, on the contrary, slow down. To perform CTG, a sensor is used to determine the tone of the uterus. It is placed on the stomach above the navel, shifted to the right corner of the uterus.

The second sensor is placed in the projection of the fetal back; it records the heart rate. The woman is given a special button in her hand, which she presses when movement occurs. Recording duration is 20 minutes.

Fetal heart rate is extremely important:

• The work of the kidneys depends on heart contractions. Decreased urine output leads to a decrease in the amount of amniotic fluid.
• Heart rate may indicate oxygen starvation, which in various pathological conditions leads to acidosis, which depresses the nervous system and cardiac activity.

Ultrasound is performed continuously for 30 minutes. If all indicators are recorded as normal, then the time is reduced. During an ultrasound, the doctor evaluates:

• Respiratory movements of the chest - they are unstable, arise and disappear spontaneously. An episode is the moment from the beginning to the end of respiratory movements. Normally it is at least 60 s per half hour.
• Flexion or extension movements of the torso or limbs - tone is assessed by them. If the neck, arms or legs are in an extended position, this is considered abnormal and may indicate serious problems, including antenatal death.
• Motor activity, that is, any movement, displacement, rotation of the torso, arms or legs. Their total number during the study is calculated.
• The volume of amniotic fluid - it reflects the metabolic state of the fetus.
• The degree of maturity of the placenta indicates possible causes of hypoxia.

Decoding the BPP

The severity of each indicator is assessed in points from 0 to 2. The norm of the biophysical profile of the fetus indicates the absence of risk.

Non-stress test:

• 2 points if there were 5 episodes of heart rate acceleration in response to movement lasting 15 seconds or more. force of at least 15 blows;
• 1 point is given for 2-4 such episodes;
• episode - 0 points.

Breathing movements:

• receive the maximum rating if there were 1 or more episodes lasting 60 seconds or more;
• periods 30-60 sec. get 1 point;
• absence or breathing for less than 30 seconds. - 0 points.

Motor movements:

• 3 or more motor movements - 2 points;
• for 1-2 movements they give 1 point;
• 0 if there is no movement.

Flexion or extension movements:

• Muscle tone is considered normal, in which at least one episode of flexion-extension of the limb and back is recorded, 2 points are given for it.
• A point is given if one of the listed episodes is present.
• Stable extension, open palms - 0 points.

Amniotic fluid:

• must be in all pockets, depth 2 cm;
• pockets 1-2 cm are scored 1 point;
• less than 1 cm - 0 points.

Degree of maturity of the placenta:

• 2 points are given for 0, 1, 2 degrees of placental maturity;
• if its visualization is difficult, give 1 point;
• aging placenta grade 4 is scored 0 points.

The received scores are summed up:

• The maximum possible amount is 12 points. A biophysical profile of the fetus of 8 and 9 points is also considered normal.
• A result of 6-7 is considered doubtful. It requires additional observation and examination. A woman may be offered hospitalization in the pregnancy pathology department at the maternity hospital.
• A score of 5 or less indicates deep suffering of the fetus, which can lead to its death.

In the latter case, after the ultrasound room, the woman is urgently sent to hospital by her obstetrician-gynecologist. In difficult situations, early delivery by cesarean section is performed to save the child’s life.

Yulia Shevchenko, obstetrician-gynecologist, especially for the site

Useful video

Biophysical profile of the fetus is a comprehensive assessment of data from a stress-free test and ultrasound in real time, allowing one to judge the condition of the fetus.

The biophysical profile of the fetus includes five parameters, assessed on a two-point system. A score of 6 or more points is considered satisfactory. Sometimes a 6th parameter is added - placenta maturity.

1. Breathing movements. The fetus makes respiratory movements sporadically: several movements occur in a row, then a break follows. Normally, at least one episode of respiratory movements lasting 30 seconds is recorded within 30 minutes.
2. Fetal movements. The fetus must make at least three pronounced movements within 30 minutes (simultaneous movements of the limbs and torso are considered one movement).
3. Fetal tone - at least one episode of movement of the limbs from a flexion to an extended position and a rapid return to the original state (within 30 minutes).
4. Fetal reactivity (stress-free test) - the presence of two or more periods of heart rate acceleration with an amplitude of at least 15/min and a duration of at least 15 s, associated with fetal movement, during a 10-20-minute observation.
5. Estimation of the amount of amniotic fluid. If there is a sufficient amount of amniotic fluid, a column of amniotic fluid (a section of amniotic fluid free from parts of the fetus and umbilical cord) of at least 2 cm should be visualized in two mutually perpendicular sections in most of the uterine cavity.

Hypoxia. With increasing hypoxemia, progressive inhibition of the biophysical functions of the fetus begins. Changes in some parameters (respiratory movements, motor tone and reactivity) occur immediately after an episode of asphyxia, while changes in other parameters, for example, the amount of amniotic fluid, require more time; such parameters change during chronic hypoxia.

1. Acute hypoxia

• The fetal breathing movements are the first to stop
• Then the stress-free test becomes non-reactive
• The third change is the disappearance of fetal motor activity
• Lastly, the tone of the fetus disappears.

2. With chronic hypoxia, the volume of amniotic fluid decreases over several days or weeks.

Fetal biophysical profiling is used in some clinics as the primary antenatal examination, while in others it is used only when the contractile stress test is positive or inconclusive. For example, the biophysical profile of the fetus is determined in the case of premature rupture of amniotic fluid. With the development of chorioamnionitis, complicating premature rupture of membranes, the biophysical profile of the fetus is rarely satisfactory. In addition, with chorioamnionitis, the reactivity of the stress-free test disappears.