Obstetrics and gynaecology department №2 Methodical recommendations for students of 4th year of stomatological faculty for practical lessons in obstetrics icon

Obstetrics and gynaecology department №2 Methodical recommendations for students of 4th year of stomatological faculty for practical lessons in obstetrics




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НазваObstetrics and gynaecology department №2 Methodical recommendations for students of 4th year of stomatological faculty for practical lessons in obstetrics
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Head of obstetrics and gynaecology department №2

docent, k. m. n. O. V. Bulavenko

Obstetrics and gynaecology department №2

Methodical recommendations for students of 4th year of stomatological faculty for practical lessons in obstetrics


Theme: Parturient canal and fetus as an object of childbirth. The structure of female pelvis, measurements. Mature fetal head structure. Early pregnancy diagnostics. Late pregnancy diagnostics. Fetus position, the type of position, presentation. Auscultation of heartbeats. Additional methods of examination at second part of pregnancy. Self-guided work.


  1. Scientific and methodological explanation of the topic

The main theme in obstetrics. It is important for further study of obstetric discipline, particularly about delivery biomechanism of childbirth, clinical correlation of fetus and pelvis.


Il. Scientific and educational goals


To generate skills the student should know:

  1. The structure of female pelvis.

  2. The planes of small pelvis and their dimensions.

  3. The main external dimensions of pelvis.

  4. Additional dimensions of pelvis.

  5. The methods of measurements of true conjugate.

  6. The pelvic muscles.

  7. Mature fetal head structure.

  8. Sutures and fontanels on fetal head.

  9. Dimension of fetal head, morphologic features of body.

  10. Early pregnancy signs.

  11. External obstetric examination maneuvers.


The student should be able to:

  1. Measure external dimensions of the pelvis.

  2. Calcu­late the true conjugate.

  3. Calcu­late the foreseeable fetal body weight and height .

  4. Detect the attitudes of fetus (fetus position, the type of position, presentation).

  5. Detect the signs of fetus maturity.


III. The basic knowledge:

  1. Female genitals anatomy.

  2. The structure of female pelvis.

  3. Mature fetal head structure.



IV. Methodical recommendations for practical training:

The structure of female pelvis, measurements

From considerations of obstetrics the female pelvis is divided into two parts: the large and small pelvis. The border between them goes along the innominate line (linea innominata). The large pelvis is bounded by the wings of ilia on either side, by the spine — from be­hind, and there is no wall from the front. The small pelvis is formed by the pubic bones branches from the front, by parts of the bones forming the femoral fossa — on the sides, and by the sacral and pelvic bones — from behind .

During delivery the small pelvis, as a dense bone tunnel, limits and defines the dimensions, form, and direction of the parturient canal, to which the fetus moves and must conform, changing its own configuration.

Pelvis measuring is the most important method of pelvis examina­tion.

Most internal dimensions of the pelvis are inaccessible for mea­surement, therefore usually its external dimensions are measured, by which the internal ones are evaluated.

The pelvis is measured with the help of the pelvimeter.

Usually there are measured four main dimensions of the pelvis: three transversal and one straight. Distantia spinarum is the distance between the anterosuperior axes of the ilia. This dimension makes 25 cm. Distantia cristarum is the distance between the most distant points of the iliac crests; it makes 28 cm on average. Distantia trochanterica is the distance between the greater trochanters. This di­mension makes 21 cm.

Conjugata externa (external conjugate) is the straight dimension of pelvis. The woman is put on her side; the leg lying below is bent in the hip and knee joints, the other leg is straightened. The end of the pelvim­eter is set in the middle of the superior-external border of the symphy­sis, the other end is pressed to the supersacral fossa, which is situated between the process of the fifth lumbar vertebra and the beginning of the first sacral vertebra. The external conjugate makes 20 cm.

Dimensions of small pelvis are of great importance in obstetric-practice since the course and completion of delivery depend on them. But most dimensions of small pelvis can not be measured directly. The large pelvis is not of big importance for the birth of a child, but it is possible to judge about the form and size of small pelvis by its dimensions. The small pelvis cavity is the space between its walls, limited from above and from below by the area of brim and the area of pelvic out­let. It looks like a cylinder truncated from the front backwards in such a way that the anterior part (directed to the womb) is three times as low as the posterior one (directed to the sacral bone). There are differentiated four planes in the small pelvis cavity: the area of brim, the pelvic plane of greatest dimensions, the third parallel pelvic plane, and the area of pelvic outlet.

The planes of small pelvis and their dimensions:

a) the area of brim is limited from behind with the promontory
of sacral bone, on the sides — with the terminal lines of hip bones,
from the front — with the upper margin of pubic bone and symphysis.
There are differentiated four dimensions.

The straight dimension — the distance from the promontory of sacral bone to the most protrudent point of the superointernal margin of symphysis, it is also called the true or obstetric conjugate (conju­gata vera), makes 11 cm. There is also distinguished the anatomic co­njugate (conjugata anatomic) — the distance from the promontory of sacral bone to the upper margin of symphysis, it is by 0.3 cm larger than the obstetric one.

The transversal dimension — the distance between the utmost points of the arcuate lines of ilia (linea innominata); it makes 13 cm.

The oblique dimension (left and right) — the distance from the left sacroiliac joint (articulatio sacroiliaca) to the right iliopubic emi­nence (eminentia iliopubica) and vice versa; it makes 12 cm.

b) the pelvic plane of greatest dimensions is limited from behind
by the junction of the second and third sacral vertebrae, from the
sides — by the middle of femoral fossae, from the front — by the mid­
dle of the internal surface of symphysis. In this plane two dimensions
are differentiated — straight and transversal.

The straight dimension — from the projection of the junction of the second and third sacral vertebrae to the middle of the internal surface of symphysis; it makes 12.5 cm.

The transversal dimension — between the middles of femoral fos­sae; it makes 12.5 cm.

c) the third parallel pelvic plane is limited from the front by the
inferior margin of symphysis, from behind — by the sacrococcygeal
joint, from the sides — by the axes of ischial bones. There are differen­
tiated two dimensions of the third parallel pelvic plane — straight and
transversal.

The straight dimension — from the sacrococcygeal joint to the middle of the inferior margin of pubic symphysis; it makes 11 cm.

The transversal dimension — between the internal surfaces of is­chial bones axes; it makes 10.5 cm;

d) the area of pelvic outlet is limited from the front by the infe­
rior margin of symphysis, from behind — by the pelvic bone apex,
from the sides — by the internal surfaces of ishial tuberosities. The
dimensions of the area of pelvic outlet are straight and transversal.

The straight dimension — the distance from the middle of the in­ferior margin of symphysis to the pelvic bone apex; it makes 9.5 cm (during delivery, when the fetal head is being born, the pelvic bone reclines by 1.5 cm and the straight dimension increases to 11 cm).

The transversal dimension — the distance between the internal surfaces of ishial tuberosities; it makes 11 cm.

The dimensions of the pelvic outlet can be measured directly. For this purpose the pregnant is put on her back, the legs are bent in the hip and knee joints, moved sideways and pulled to the stomach. The mea­surement is conducted with a measuring tape or a special pelvimeter.

The straight dimension is measured between the mentioned above landmarks. To measure the transversal dimension-one should add 1.5 cm to the obtained distance between the internal surfaces of ishial tu­berosities (9.5 cm), taking into account the soft tissues thickness.

The line, which goes in the middle of all the straight dimensions of the planes, is called the axis of pelvis (the plane of pelvic canal). The pubic angle makes 90—100°, the angle of pelvic inclination — 55—60°. The height of symphysis is measured during vaginal examination and makes 3.5—4 cm.

The most important dimension for pelvis evaluation is the true conjugate, which can not be measured directly. Therefore it is calcu­lated from the dimensions, which are accessible to measurements — the external and diagonal conjugates.

To find the true conjugate 8 cm are subtracted from the value of the external conjugate if the circumference of the radiocarpal articu­lation < 14 cm; 9 cm — if the circumference of the radiocarpal articu­lation makes 14—16 cm; 10 cm — if the circumference of the radiocar­pal articulation > 16 cm. For example: 20 cm - 9 cm = 11 cm.

The diagonal conjugate is the distance from the inferior margin of symphysis to the most protrudent point of the sacral bone promontory. The diagonal conjugate is measured by means of vaginal examination.

When introduced into the vagina, the index and long fingers move along the hollow of sacrum to the promontory of sacra, the tip of the long finger is fixed on the promontory apex, and the edge of palm rests against the inferior margin of symphysis. The place, where the doctor's hand touches the inferior margin of symphysis, is marked with a finger of the other hand. After the fingers are taken out of the vagina, the distance from the tip of the long finger to the marked point of the palm edge encounter with the inferior margin of symphy­sis is measured with a measuring tape or a pelvimeter.

The diagonal conjugate makes 13 cm on average. If it is impossible to reach the sacral bone promontory with a fingertip, the diagonal conjugate dimension is considered close to normal.

In order to find the true conjugate one has to subtract 1.5—2 cm from the diagonal conjugate depending on the circumference of the radiocarpal articulation: if the circumference makes 15 cm — 1.5 cm, if it makes 16 cm and more — 2 cm.

The main external pelvis dimensions and diagonal conjugate are measured in all pregnant and parturient women without exception.

If examination shows that the main dimensions are irregular and narrow pelvis is suspected, additional measurements are conducted.

^ The pelvic muscles

The perineum forms the pelvic floor, closing its outlet. In obstet­rics the notion of perineum is narrower than in anatomy, where perineum is the space between the posterior commissure of pudendal lips and the anterior margin of anus.

The floor of small pelvis is formed by two diaphragms — pelvic and urogenital.

The pelvic floor muscles consist of three layers.

The superficial (external) layer is formed by such muscles: is­chiocavernous (m. ischicavernosus) — begins from the ishial tuberosi­ty and interweaves with the clitoris tissues; bulbocavernous (m. bul-bospongiosus) — begins from the tendinous center of the perineum and attaches to the vaginal walls; the external sphincter muscle of anus (m. sphincter ani externus) — begins in the region of the pelvic bone apex, envelops the anus, and interweaves into the tendinous centre of the perineum; the superficial transverse muscle of perineum (m. transversum perinei superficialis) — begins from the ishial tuber­osity and ends in the tendinous centre of the perineum.

The middle layer of the pelvic floor muscles consists of the uro­genital diaphragm, which is located between the symphysis pubis, pu­bic and ischial bones in the form of a triangle. It is formed by the sphincter muscle of urethra (m. sphincter urethrae internum) and the deep transverse muscle of perineum (m. transversus perinei pro­fundus).

The internal layer of the pelvic floor muscles is named the pelvic diaphragm. This is the strong binate elevator muscle of anus (m. leva­tor ani), which consists of muscle bundles: pubococcygeal (m. pubo-coccygeus) and iliococcygeal (m. iliococcygeus). The coccygeal muscle (m. coccygeus) is rudimentary and attaches to the lower vertebrae of sacral and pelvic bones.


Morphologic features of the fetal head and body

Mature fetal head structure. On the fetal head there are sutures (frontal, sagittal, coronal, lambda) and fontanels (large, small, and two lateral on each side).

The frontal suture is situated between the frontal bones, the sagit­tal suture — between the parietal bones, the coronal suture — between both frontal and both parietal bones, the lambda suture — between two parietal and the occipital bone.

The large fontanel (anterior) is located between the posterior parts of both frontal and anterior parts of both parietal bones; it is a rhomboid connective tissue plate. The small fontanel (posterior) is triangular and is located between the posterior parts of both parietal bones and the occipital one.

The large and small fontanels are joined with the sagittal suture.

The lateral fontanels are situated: anterior — between the frontal, temporal and cuneiform bones, posterior — between the temporal, pa­rietal and occipital bones. They are closed in a mature fetus.

The fetal head has the following dimensions and corresponding circumferences:

  • the straight dimension {d. frontooccipitalis) is measured from the bridge of nose to the most protrudent point of occiput, makes 12 cm; the circumferencia frontooccipitalis makes 35 cm;

  • the large oblique dimension (d. mentooccipitalis) is measured from the chin to the most distant point of occiput, makes 13.5 cm. The corresponding circumference makes 41 cm;

  • the small oblique dimension (d. suboccipito-bregmaticus) is measured from the suboccipital fossa to the middle of large fontanel, makes 9.5 cm. The corresponding circumference makes 32 cm;

---the middle oblique dimension (d. suboccipito-frontalis) is mea­sured from the occipital fossa to the margin of the pilar part of fore­head, makes 10 cm. The corresponding circumference makes 33 cm;

---the vertical dimension (d. sublinguabregmaticus) is measured from the middle of large fontanel to the hyoid bone, makes 9.5 cm; The corresponding circumference makes 33 cm;

  • the large transversal dimension (d. parietalis) is measured be­tween the most distant points of parietal protuberances, makes 9.5 cm;

  • the small transversal dimension (d. parietalis) is measured be­tween the most distant points of coronal suture, makes 8 cm;

  • the diameter of the pelvic area (d. interotrochanterica) makes 9.5 cm. The corresponding circumference makes 28 cm;

  • the diameter of the shoulder girdle (d. biacromalis) makes 12 cm. The corresponding circumference makes 35 cm.



Mature and full-term fetus signs

Fetal maturity signs:

1. mature fetus' height is more than 47 cm;

2. mature fetus' weight is more than 2,500 g;

3. the umbilical ring is located in the middle between the uterus and the xiphoid process;

4. the skin is pink, healthy, developed. Vernix caseosa is found only in the inguinal and axillary folds;

5. the fingernails cover the ends of finger bones;

6. the hair on the head is 2 cm long;

7. the cartilages of nose and ears are tight;

8. in boys the testicles are in the scrotum; in girls the large lips of pudendum cover the clitoris and small lips of pudendum.

The fetus is considered full-term if it is born in the period from the 37th to the 41st week of pregnancy inclusive. Most often there is perfect coincidence between fetal maturity and its being full-term. Still, sometimes a child is born before the term being absolutely ma­ture by its development. At unfavorable conditions of intrauterine development a full-term child may have signs of immaturity.


^ Early pregnancy diagnostics

Early pregnancy is diagnosed by a combination of signs, data of gyne­cologic examination, instrument and laboratory methods of investi­gation.

Pregnancy signs are divided into three groups.

1. Doubtful signs are various subjective sensations and objec­
tively detected changes in the organism except for the changes in the
internal genital organs:

  1. subjective phenomena — nausea, vomiting, loss or increase oi appetite, gustatory caprices (addiction to salty or sour food, chalk, etc.), changes of olfactory sensations (aversion to the smell of meat products, tobacco smoke, etc.), slight fatigability, sleepiness;

  2. objective phenomena — pigmentation of the face skin, white line, external genital organs, increased pigmentation of the nipples and the skin around them.

2. Probable signs are objective signs detected in the genital or­
gans, mammary glands, and also with the help of immune response to
pregnancy. These are characteristic of pregnancy, though sometimes
may arise because of other reasons. The signs include cessation of
menstruation at the childbearing age, mammary glands enlargement,
and nipple discharge of milk or colostrum.

Probable signs also include gynecological examination data: in­spection of the external genital organs, examination of the neck of uterus with the help of specula, bimanual gynecological examination. Softening and cyanosis of the vestibule of vagina, vagina itself, and the neck of uterus may be observed; enlargement and softening of the uterus, change in its form; increase of the contractile capacity of uter­us (short-term hardening of the softened uterus).

During the examination of the gravid uterus the most important signs are the following:

a) the Genter's sign: vaginal examination during early pregnancy shows a cristate protuberance on the anterior surface of uterus, directly on its midline; the protuberance does not spread either to the fundus, or its posterior surface, or the neck;

  1. the Hegar's sign: vaginal examination shows softening in the region of isthmus, as a result the fingers of the external and internal hands easily meet in this place. The neck is felt as a more dense body ;

  2. the Piskachek's sign: vaginal examination shows that the con­tours of the fundus of uterus and the regions of its angles appear to be irregular. The angle corresponding to the place of egg implantation protrudes much more than the opposite one. The whole uterus ap­pears to be asymmetric

  3. the Snegirev's sign: during vaginal examination the gravid uter­us begins contracting under the fingers and becomes denser as a result of mechanical irritation.

Probable signs include immune responses to pregnancy, which are based on HCG detection in the urine or blood plasma. HCG is pro­duced by the trophoblast, then by the chorion, placenta. This hor­mone consists of alpha- and beta-subunits. Production begins from the 7th—8th day after fertilization, therefore laboratory diagnostics is possible after this term. Since the method has a threshold of sensitivi­ty, one should take morning urine for the investigation — it has the highest concentration of the hormone. Detection of beta-HCG in the plasma is more reliable. It should be emphasized that though HCG is produced by trophoblast, the reaction is referred to probable signs, because at such pathological state as chorioepithelioma positive reac­tions to HCG are also observed. Besides, after abortion reactions re­main positive during 7—10 days, and at pathological states (tropho­blast diseases) — during 2—4 months. The lower threshold of sensi­tivity of the method is 5 IU/L.

3. True signs of pregnancy are conclusive proofs of pregnancy in the examined woman. All the signs of this group are objective and originate from the fetus. They include the signs shown by intravagi-nal ultrasound investigation. Other true signs reveal beginning from the 20th week of pregnancy and do not belong to the signs of early pregnancy; they are: fetal movement detected manually or during auscultation (not the movement felt by the pregnant woman); aus­cultation of fetal heart tones; palpation of fetal parts (the head, legs, buttocks, arms); detecting fetal heartbeats by means of cardiotoco-graphy. It should be noted that application of the color impulsive Doppler is forbidden till the end of the crucial period of organogene­sis. This is connected with the fact that the usage of modern Doppler technologies at transvaginal echographies if pregnancy term is less than 10 weeks has a potential threat of teratogenic thermal effect as a result of embryo heating.

Currently the standard of early pregnancy diagnostics is the com­bination of two methods:

a). detecting beta-HCG in the urine or blood plasma;

b). transvaginal ultrasound investigation.

The uterus dimensions during the first 3 months of pregnancy, when it is still in the small pelvis cavity, are detected by means of bi­manual gynecological examination, further at abdominal palpation — by the height of uterine fundus standing.

The accuracy of pregnancy term determination depends on the early visit of the woman to the antenatal clinic. It is recommended to conduct the primary examination of the woman by two specialists-obstetricians. Taking into account the difficulty of detecting the term of fertilization, pregnancy is diagnosed with a week interval (for ex­ample: pregnancy of 8—9 weeks). Pregnancy term is detected more reliably on the basis of measuring the parameters of the embryo and fetus by the method of ultrasound investigation.

^ Late pregnancy diagnostics

The methods of late pregnancy investigation include: general exami­nation of the pregnant or parturient woman, external measuring of the uterus and pelvis of the woman, external and internal obstetric examination; auscultation of fetal heartbeats, auxiliary instrument and apparatus methods of investigating the fetal condition (see the chapter Fetal Condition Imaging and Assessment).

Anamnestic data — pregnancy term calculation in weeks with the help of the pregnancy table from the date of the last menstruation and from the date of the first fetal movement (in para I the first fetal movement is usually felt beginning from 20 weeks of pregnancy, in para II — from 18 weeks). To calculate the term of delivery by the date of the last menstruation one has to count 3 months off it and add 7 days to the obtained date.

Results of objective examination — the height of uterine fundus standing over the womb at measuring with a measuring tape in rela­tion to a standard gravidogram, external obstetric examination (the Leopold's maneuver), auscultation of fetal heartbeats (beginning from 20 weeks), the data of ultrasound fetometry.

^ Fetus Attitude in the Uterine Cavity (fetus position, the type of position, presentation)

Attitude of fetus is the relation of small fetal parts and head to the body. At normal attitude the spine is bent to the abdominal surface, the head is pulled to the chest, the arms are bent in the elbow joints and folded on the chest, the legs are bent in the knee and hip joints, pulled to the stomach.

Fetal lie is the relation of the longitudinal axis of fetus to the longi­tudinal axis of uterus. There are differentiated the following fetal lies:

--- longitudinal — the longitudinal axis of fetus and the longitudi­nal axis of uterus coincide;

--- transversal — the longitudinal axis of fetus crosses the longitu­dinal axis of uterus;

  • oblique — the longitudinal axis of fetus crosses the longitudi­nal axis of uterus at a sharp angle.

Fetus position is the relation of the fetal back to the right and left sides of uterus. Two positions are differentiated:

  • the first — the fetal back is turned to the left;

  • the second — the fetal back is turned to the right.

At transversal and oblique lie the position is detected by head lo­cation: the head is on the left of the maternal stomach midline — the first position, on the right — the second.

The type of position relation of the fetal back to the anterior or posterior uterine wall. There are two types:

--- anterior — the fetal back is turned to the front;

--- posterior — the fetal back is turned backwards.
Presentation is the relation of a big fetal part (the head or pelvis) to the inlet of small pelvis. There are differentiated cephalic and pel­vic presentations.

A presenting part is the part of fetus, which is located closer to the inlet and is the first to go through the maternal passages. At the bent fetal head the most low located part is the occiput. Such presentation is called vertex and is observed most often.

Considerably less frequently the head is unbent. Depending on the level of unbending the presenting part may be the crown (sincipi­tal presentation), forehead (brow presentation), or face (face presen­tation).

At pelvic presentation the most low located part might be the but­tocks (breech presentation) or feet (foot presentation).

The major segment of fetal head is understood as the largest cir­cumference of the head, with which it goes through the planes of small pelvis depending on its fitting. At vertex presentation, when the head is fitted into the pelvis in bent position, the largest circumfer­ence is the one corresponding to the circumference of the small oblique size. At extended fitting of the head the major segment will be different (depending on the degree of deflexion).

The minor segment of fetal head is considered by convention the part of the head smaller than the major segment, with which the head goes through the smaller pelvis planes.

^ EXTERNAL OBSTETRIC EXAMINATION MANEUVERS (THE LEOPOLD'S MANEUVERS)

The first maneuver. The purpose is to detect the standing of the fundus of uterus and the part of fetus located close to the fundus of uterus. To do this, the doctor stands on the right of the pregnant woman, facing her, puts both palms on the fundus of uterus, detects the height of its standing over the womb and the part of fetus located close to the fundus of uterus.

The second maneuver. The purpose is to detect the position and position type of the fetus. Both palms are removed from the fundus of uterus and in turn palpate the parts of fetus directed to the lateral uterine walls. The back and small parts of fetus are found. At irregular position the head is adjacent to one of the lateral uterine walls.

The third maneuver. The purpose is to detect the character of the presenting part of fetus (presentation). With one hand, usually the right one, which is lying slightly above the pubis, the presenting part of fetus is covered, after what cautious movements are made with this hand to the right and to the left. At cephalic presentation a dense, spheric part is detected, which has well-defined contours. If the fetal head is not yet fitted into the area of brim, it easily moves between the thumb and the rest of fingers. At pelvic presentation a volumi­nous soft part is detected, it is not spheric and can not move.

The fourth maneuver. The purpose is to detect the level of pre­senting part standing (of the head in particular) relative to the area of brim and to the degree of its fitting. The doctor stands on the left, with the face to the lower extremities of the pregnant woman, puts both hands with palms down on the lateral parts of the lower uterine segment and palpates accessible parts of the presenting part of fetus, trying to get with the fingertips between the pre­senting part and lateral parts of the area of brim.


^ MEASURING THE ABDOMEN CIRCUMFERENCE AND THE HEIGHT OF UTERINE FUNDUS STANDING

Abdomen circumference (AC) is measured with ameasuring tape, which goes through the navel in front and through the middle of lum­bar area from behind.

The height of uterine fundus standing (HUFS) is measured with a measuring tape from the upper margin of symphysis to the most pro­truding point of the fundus of uterus. The results of HUFS measuring are compared with a standard gravidogram (normally by the 30lh week of pregnancy HUFS increase makes 0.7—1.9 cm a week; at 30—36 weeks — 0.6—1.2 cm a week; at 36 and more — 0.1—0.4 cm. If case monitoring shows lagging of dimensions by 2 cm or absence of increase during 2—3 weeks, it gives ground to suspect fetal growth inhibition).


^ CALCULATING THE FORESEEABLE FETAL BODY WEIGHT

The foreseeable fetal body weight (FBW) is approximately calcu­lated by the following formula:

FBW = AC x HUFS. More reliably fetal body weight is estimated by ultrasonic fetometry.


Auscultation of heartbeats

CTG structure and analysis:

  1. Basal fetal HR is a mean of instantaneous values of fetal HR nonregistering accelerations and decelerations. BHR is calculated in intervals in 10 min. Normal fetal BHR (normocardia) is the frequency from 110tol70bpm.

  2. HR variability is a complex parameter of fetal cardiac function. It can be assessed by the width of CTG record (HR amplitude) and by oscillations frequency.

Record width (amplitude) is measured between the absolute maxi­mum and minimum of all oscillations nonregistering accelerations and decelerations, i.e. the amount of deflection from the basal rhythm (Fig. 32).

In the given example the amplitude will make 150-135 = = 15(bpm).

There are differentiated 4 variants of amplitude:

  • monotonic — with deflections from the basal rhythm up to 5 bpm;

  • flattened (extremely wave-like, with deflections from 5 to 9 bpm);

  • wave-like — from 10 to 25 bpm;

— pulsating (saltatory rhythm) — more than 25 bpm.
Oscillations frequency is their quantity per minute.

By frequency there are differentiated low (less than 3 per min), medium (3—6 per min), and high frequency (more than 6 per min) oscillations.

By the character of origination accelerations and decelerations may be sporadic, periodical, and regular, by duration — typical and prolonged.

Sporadic — appear in response to fetal movements, are not regular.

Regular — are registered in approximately equal intervals of time and are connected with fetal movements.

Periodical — are connected with fetal vital activity, e.g. accelera­tions and decelerations arising after a labor pain or caused by umbili­cal cord compression.

Typical accelerations and decelerations last more than 15 sec, but not longer than 2 min.

Accelerations and decelerations are prolonged if basal rhythm change lasts more than 2 min.

  1. Accelerations are temporary BHR changes characterised by BHR increase during more than 15 sec (weak HR changes from 10 to 30 bpm, medium — 30—60 bpm, considerable — more than 60 bpm; Fig. 34).

  2. Decelerations — temporary BHR changes characterised by BHR decrease.

4.1. Spontaneous decelerations (dip 0). Short-term decelera­tions, last not more than 30 sec, the amplitude of 30—40 beats from the basal level. These changes have no practical meaning. De­celerations of this type may be sporadic, regular, and periodical.

4.2. Early decelerations (dip I) are periodical, i.e. are detected only if the uterus is active. Deceleration duration and amplitude correspond to the duration and intensity of parodynia.

4.3. Late decelerations (dip II) are periodical, i.e. also con­nected with parodynia, but arise later (up to 30 sec after begin­ning) and reach their high after the maximum uterine tension.

4.4. Variable decelerations (dip III) are also referred to periodical. This is a stable form of HR reduction, a combination of dip I and dip II. They are characterised by unsteady time of emer­gence relative to labor pains, different duration and form. During delivery fetal condition is assessed by the W. Fisher's scale (1976).

At normal fetal condition CTG is characterized by: BHR within 110—170 bpm (normocardia), variability (record width) — 10— 25 bpm with oscillation frequency of 3—6 cycles per min (undulating type), presence of HR accelerations and no decelerations.

Non-stress test (NST) is assessment of fetal cardiac function re­activity with the help of CTG during pregnancy in response to spon­taneous movements. The pregnant woman is in comfortable position during CTG.

NST may be reactive (norm) when during 20 min there are 2 or more accelerations of fetal heartbeats by. more than 15 bpm and last­ing not less than 15 sec connected with fetal movements. The test is areactive if there are less than 2 accelerations of fetal heartbeats by less than 15 bpm, lasting less than 15 sec, connected with fetal move­ments during 40 min of monitoring.

Stress test is assessment of fetal cardiac function reactivity by means of CTG during pregnancy in response to functional tests: oxy­tocin introduction, breath-holding, physical load of the mother, nip­ples stimulation, thermal irritation of the belly skin, or acoustic stimu­lation. This method has low predictive value concerning the fetus and a very high frequency of error-positive results.

Biophysical fetal profile (BFP) is a change of biophysical indices controlled by the central nervous system at fetal hypoxia.

Biophysical indices include: frequency of fetal respiratory move­ments, fetal motion activity, fetal tone, fetal cardiac function reacti­vity and NST, amniotic fluid volume, placenta maturity (Table 3).

Modified BFP combines NST with amniotic fluid index.

Amniotic fluid index is a total of maximal recesses with fluid in 4 quadrants of the uterine cavity: 0—5 cm — evident oligohydram­nios, 5.1—8 cm — moderate oligohydramnios, 8.1 — 18 cm — normal index, more than 18 cm — hydramnion.

Each index is assessed in points from 0 (pathology) to 2 (norm), then the total of points of all biophysical parameters is analyzed. Thus, BFP is found.

BFP is detected beginning from 30 weeks of pregnancy.

Indications to BFP:

1. Areactive NST of the fetus at CTG recording.

2. Syndrome of fetal development delay.

3. Chronic fetoplacental insufficiency.

4. A high degree of risk in the pregnant woman at some extra­genital pathology.


^ V. Organizational structure of lesson:

Organizational moments-2%;

Topic motivation -3%;

Checking the initial level of knowledge -20%;

Independent work of students under supervision of a lecturer -35%;

Checking the final level of knowledge -20%;

The rating of students` knowledge -15%;

Lecturer`s summary/conclusion, home task-5%.


^ VI. Methodical support:

The place of practical training: department of pathology pregnant, gynecology department, intensive care department, low operating, classroom.

Visual aids: tables, slides, results of laboratory examinations, case histories of pregnant women with early and late gestosis, a set of tools for abortion.


Checking questions for the assessment of the final level of knowledge

  1. The structure of female pelvis, its changes before delivery.

  2. The names of (four) bones that constitute the female pelvis.

  3. The boundaries and planes of the small pelvis, their form and dimensions.

  4. The main external and internal female pelvis dimensions.

  5. Additional measurements of the pelvis.

  6. Methods of true conjugate determination.

  7. Muscles of superficial (external) layer of the pelvic floor.

  8. Muscles of middle layer of the pelvic floor.

  9. Muscles of internal layer of the pelvic floor.

  10. Function of urogenical diaphragm.

  11. Osteocranum structure of the newborn.

  12. Configuration of sutures and fontanels of fetus head, notion of head configuration.

  13. Dimensions of a head, shoulders, buttocks of a full-term newborn.

  14. Mass and length of a full-term newborn.

  15. Parameters of a full-term and mature fetus.


Case studies for the assessment of the final level of knowledge

On pelvimetry there is noted that the diagonal conjugate equals 12.5 cm and carpus circumference is 15 cm.

  • How to determine true conjugate?

Which suture can be determined on the presenting part during internal examination if under the pubic it is conjugated with a triangular shape fontanel and at sacrum – with rhomb-shaped fontanel? Reproduce this situation on the phantom.

Which suture can be determined on the presenting part if in front under the pubic it is conjugated with a hornlike fontanel and at sacrum – with a triangular shape fontanel? Reproduce this situation on the phantom.

The newborn boy weighs 2, 500 grams, 45 cm long.

  • Is it a full term infant?

  • What are the other necessary signs of this?

On measuring the main pelvis dimensions there was noted that the interspinal distance Distantia spinarum equals 26 cm, intercrista one Distantia cristarum equals 28 cm, intertrochanteric Distantia trochanterica one is equal 31 cm, external conjugate is 20 cm. On internal examination the promontory was not approached.

  • Are there any indications for additional measurements of the pelvis?

On pelvimetry there is noted that the diagonal conjugate equals 12 cm. The circumference of the radiocar­pal articulation is 14 cm.

  • What is true conjugate equal to?

On pelvimetry there is noted that the diagonal conjugate equals 12.5 cm and carpus circumference is 15 cm.

  • What is true conjugate equal to?

True conjugate equals 10.5 cm

On measuring the main pelvis dimensions there is noted that the interspinal distance Distantia spinarum equals 24 cm, intercrista one Distantia cristarum equals 25 cm, intertrochanteric one Distantia tro-chanterica is equal 29 cm. External conjugate is 20 cm. On internal examination there is noted that the diagonal conjugate equals 12 cm.


  • Are there any indications for additional pelvic measurements?

On measuring the main pelvis dimensions there is noted that the interspinal distance^ Distantia spinarum equals 26 cm, intercrista one Distantia cristarum equals 28 cm, intertrochanteric one Distantia tro-chanterica is equal 31 cm, external conjugate is 20 cm. On internal examination the promontory was not approached.

  • Are there any indications for additional pelvic measurements?

^ There are no indications for additional pelvic measurements.

Which suture can be determined on the presenting part on internal examination if in front it is conjugated with a triangular shape fontanel and at the back – with a rhomb-shaped fontanel? Reproduce this situation on the phantom, when the small fontanel is under the pubic and the big one is at the sacrum bone.

^ One can determine saggital suture

The newborn boy weighs 2, 500 grams, 45 cm long.

  • Is it a full term infant?

  • What are the other signs necessary to be taken into consideration for answering this question?

The infant is immature. For diagnostic adjustments one should consider the following signs: the position of umbilical ring, skin coloration, presence and amount of lubricant, length of nails, hair, and consistency of nose and ear cartilage, the condition of external genitals.


Test questions for the assessment of final level of knowledge

On pelvimetry it is found out that the diagonal conjugate equals 12 cm. The circumference of the radio carpal articulation is 14 cm.

  • What is true conjugate equal to?

A.10.5 cm

B.10 cm

C. 11 cm

D. 9.5 cm

On the presenting head one can palpate the triangular shape conjunctive tissue plate where three sutures come together.

  • Which fontanel is being palpated?

A. Big fontanel

B. Side front fontanel

C. Small fontanel

D. Side back fontanel

Methodical support:


The place of practical training: classroom, delivery room, compartment of pregnant pathology, children’s compartment.


Visual aids: tables, model of pelvis, centimeter tape, pelviometr, case studies and test questios.


Appoved at the chair meeting from “___” _____________________ 200__ year,

minutes № ___ .


Revised at the chair meeting from “___” _____________________ 200__year,

minutes № ___

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