Dimensions of the fetal head. Small oblique size. Medium oblique size. Straight size. Large oblique size. Vertical size. Transverse size of fetal shoulders

Possibilities and abilities of the fetus And now let's see what the capabilities and abilities of the fetus are. It must be said that his sense organs and corresponding brain centers develop already by the third month of pregnancy. Vision, for example, begins to develop from the second week.

Breech presentation of the fetus While in the uterus, the fetus changes its position several times during pregnancy. IN last weeks the baby turns and takes the most convenient position for childbirth, with his head facing the exit. However, in approximately 3–5% of cases it lies with its legs down.

The power of the forbidden fruit There are foods that you do not want to eat, but you should not perceive them as “harmful.” If any product is considered harmful, it can acquire the power of the forbidden fruit. And then a mystical thing will happen, but in reality

Periods of fetal development During pregnancy, which lasts an average of 280 days, two periods of fetal development are distinguished - germinal (embryonic), lasting from the moment of fertilization of the egg to 8 weeks of pregnancy, and fetal (fetal), lasting from 8 weeks of pregnancy.

Frontal presentation of the fetus The transitional position from the anterior to the front is more common; insertion of the head is very rare. Causes of occurrence - anatomically or clinically narrow pelvis, small fetal size, shortening of the umbilical cord, decreased uterine tone and

Characteristics of the full-term fetus. Definition of maturity.

The concept of fetal maturity is determined by a number of characteristic signs of its physical development. The concept of full-term fetus is determined by the length of its stay in the uterus from the moment of conception to birth.

Full term A fetus is considered to be born after 37 weeks of gestation with a body weight of 500 g or more (on average 3500 g) and a length of 35 cm or more (on average 50-52 cm). A live, full-term baby shows great activity, moves its limbs, and makes a loud cry.

A mature fetus has a fairly developed subcutaneous fat layer, pink skin color, dense cartilage ears and nose, hair on the head is 2-3 cm long. The fluff is preserved only on the shoulder girdle in the upper back; umbilical ring located midway between the pubis and the xiphoid process. In boys, the testicles are lowered into the scrotum; in girls, the labia minora and clitoris are covered by the labia majora.

Signs of fetal maturity. The maturity of a newborn baby is judged by a combination of a number of signs.

1. The length (height) of a mature, full-term newborn is on average 50 - 52 cm (ranges from 48 to 57 cm), body weight is 3200 - 3500 g (ranges from 2600 to 5000 and above).

Length is a more constant value than body weight, so it more accurately reflects the degree of fetal maturity.

It should be noted that nowadays most children are born larger than a few decades ago. This is due to the improvement in material conditions and cultural level of the people of many countries. In accordance with this, the average body weight and height of newborns is greater than in previous years (average height 50 cm, body weight 3000 g).

The growth of the fetus is influenced by the mother's nutrition (with adequate nutrition, children are larger), the general regime of the pregnant woman, the gender of the child (the average body weight and height of boys is greater), the mother's age (in young and old children the weight of children is smaller), the number of previous births (the weight of the fetus increases during subsequent births), hereditary and other factors. Fetal growth slows down with many maternal diseases, especially severe ones. Retarded body weight and growth are associated with disturbances in the nutritional conditions and gas exchange of the fetus, intoxication, hyperthermia and other unfavorable factors that arise from maternal diseases.

Post-term babies are usually larger than full-term babies.

In case of immunological incompatibility according to the Rh factor, diabetes mellitus Often large children are born with large body weight (sometimes height), which is due to the occurrence of pathological processes.

Newborns with a length of more than 47 cm are considered mature, those with a length of 45 cm and less are considered immature. Determination of maturity or immaturity of newborns with a length in the range of 45 - 47 cm is made in each case based on a particularly careful analysis of all signs. The conclusion about the maturity of such children is made by an obstetrician and a pediatrician jointly. In the absence of data on the growth of the newborn, his body weight is taken into account, and a newborn with a body weight below 2500 g is considered immature.

A mature newborn has a convex chest, the umbilical ring is located midway between the pubis and the xiphoid process.

The skin of a mature newborn is pale pink, the subcutaneous fat layer is well developed, and there are remains of a cheese-like lubricant on the skin; there is fluff only on the shoulders and upper back; The length of the hair on the head reaches 2 cm, the nails extend beyond the fingertips.

Ear and nasal cartilages are elastic.

In boys, the testicles are lowered into the scrotum; in girls, the labia minora and clitoris are covered by the labia majora.

The movements of a mature newborn are active, the cry is loud, the eyes are closed, and he takes the breast well.

Head of a mature fetus. The study of the shape and size of the fetal head is particularly important in obstetrics. In the vast majority of births (96%), the head passes through the birth canal first, making a series of sequential movements - turns.

The head, due to its density and size, experiences the greatest difficulty when passing through the birth canal. After the birth of the head, the birth canal is usually sufficiently prepared for the advancement of the torso and limbs of the fetus. The study of the head is important for the diagnosis and prognosis of labor: the location of the sutures and fontanelles is used to judge the mechanism of labor and its course.

The head of a mature fetus has a number of features. The facial bones are firmly connected. The bones of the cranial part of the head are connected by fibrous membranes, which determine a certain mobility and displacement in relation to each other. These fibrous membranes are called sutures. Small spaces where the sutures intersect are called fontanelles. The bones in the area of ​​the fontanelles are also connected by a fibrous membrane. As the head passes through the birth canal, the sutures and fontanelles allow the bones of the skull to overlap each other. The bones of the skull bend easily. The structural features of the bones give the head plasticity; it can change shape, which is extremely important for passing through it. birth canal.

The fetal skull consists of two frontal, two parietal, two temporal and one occipital, sphenoid and ethmoid bones. In obstetrics special meaning have the following seams (Fig. 25).

The sagittal (sagittal) suture connects the right and left parietal bones; in front the seam passes into the anterior fontanelle, in the back into the posterior one.

The frontal suture is located between the frontal bones; has the same direction as the arrow-shaped seam.

The coronal suture connects frontal bones with parietal, runs perpendicular to the sagittal and frontal sutures.

The lambdoid (occipital) suture connects the occipital bone to the parietal bone.

In the area where the seams join, there are fontanelles (spaces free from bone tissue). The anterior and posterior fontanelles are of practical importance.

The anterior (large) fontanelle is located at the junction of the sagittal, frontal and coronal sutures and has a diamond shape. Four sutures extend from the anterior fontanel: anteriorly - frontal, posteriorly - sagittal, to the right and left - the corresponding sections of the coronal suture.

The posterior (small) fontanelle is a small depression in which the sagittal and lambdoid sutures converge. The posterior fontanelle is triangular in shape; Three sutures extend from the posterior fontanel: anteriorly - sagittal, to the right and left - the corresponding sections of the lambdoid suture.

It is important to know the following bumps on the fetal head: occipital, two parietal, two frontal.

Dimensions of the head of a mature fetus.

1. Straight size - from the glabella, glabella, to the occipital protuberance 12 cm. The head circumference corresponding to the straight size is 34 cm.

2. Large oblique size - from the chin to the occipital protuberance 13-13.5 cm. The head circumference corresponding to this size is 38 - 42 cm.

Small oblique size - from the suboccipital fossa to the anterior corner of the large fontanel 9.5 cm; head circumference corresponding to given size, 32 cm.

The average oblique size is from the suboccipital fossa to the border of the scalp of the forehead 10 cm. The circumference of the head corresponding to this size is 33 cm.

The sheer, or vertical, size is from the top of the crown (crown) to the sublingual area 9.5 -10 cm. The circumference of the head corresponding to this size is 32 cm.

6. transverse size - the greatest distance between the parietal tubercles is 9.25 - 9.5 cm.

7. Small transverse size - the distance between the most distant points of the coronal suture is 8 cm.

Body dimensions.

1. The size of the shoulders is the diameter of the shoulder girdle 12 cm. The circumference of the shoulder girdle is 35 cm.

2. The transverse size of the buttocks is 9 - 9.5 cm. The circumference is 28 cm.

Reasons for measuring/examining the head:

1. The head is the first to pass through the birth canal, making a series of sequential movements.

2. Yavl. voluminous and densest part.

3. The fontanelles, clearly palpable during childbirth, make it possible to clarify the nature of the insertion of the head in the small pelvis.

4. The degree of density of the bones of the skull and their mobility determines the ability of the head to compress in one direction and in the other.

the fetal head is bean-shaped. Consists of 2 parts: the face and the brain (volumetric) part. Skull - consists of 7 bones connected to each other by sutures.

SEAMS: 1. Frontal - between the 2 frontal bones. 2. Sagittal – between 2 parietal bones. 3. Lambdavid - between both parietal and occipital bones. 4. Coronoid - between both parietal and frontal bones.

fontanelles: fibrous plates at the junction of sutures. The main ones:

1. Large (front) – between rear parts both frontal and anterior parts of both parietals. Represents the connection. tk. plate, in the form of a rhombus (3O3 cm). Place of intersection of 3 seams: 1,2,4.

2. Small (rear) – has a pump function. Between the posterior parts of both parietals and the occipital bone.

Large and small fontanelle conn. arrow-shaped seam.

3. Lateral (secondary): anterolateral, posterolateral.

7 head sizes: 1) Straight - S from the bridge of the nose to the occipital protuberance. L=12 cm, d=34–35 cm.

2) Large oblique - S from the chin to the most distant point of the back of the head. L=13.5 cm, d=39–41 cm.

3) Small oblique - S from the suboccipital fossa to the middle of the large fontanel. L=9.5 cm, d=32 cm.

4) Middle oblique - S from the suboccipital fossa to the anterior corner of the large fontanelle (scalp). L=10 cm, d=33 cm.

5) Large transverse - S between the most distant points of the parietal sutures. L=9.5 cm.

6) Small transverse - between the most distant points of the coronal suture. L = 8 cm.

7) Vertical (steep) – S from the middle of the large fontanel to the hyoid bone. L=9 cm, d=32–34 cm.

Pelvis with obstetric point vision

Taz: The female pelvis is wider and shorter, wings iliac bones turned to the sides, the entrance to the small pelvis has the shape of a transverse oval, the shape of the pelvic cavity is cylindrical, the angle between the lower branches pubic bones obtuse or straight.

In obstetric practice, the small pelvis is divided into 4 sections by conventional planes, which diverge fan-shaped from pubic symphysis to the sacrum. IN clinical practice The following sizes are most commonly used female pelvis: distantia spinarum – the distance between the anterior superior iliac spines is 25–26 cm; distantia cristarum – the distance between the iliac crests is 28–29 cm; distantia trochanterica– the distance between the greater trochanters is 30–31 cm; true, or obstetric, conjugate - the distance between the posterior edge of the pubic symphysis and the promontory is 11 cm. To determine the obstetric conjugate, it is necessary from the external straight size, equal to 20–21 cm, subtract 9 cm - a distance equal to the thickness of the tissues and the spinal column.

Normal sizes pelvis Definition of true conjugates

Full external pelvic measurement:

1.Distantia spinarum is the distance between the two anterior superior iliac spines (in N = 25 – 26 cm)

2. Distantia cristarum is the distance between the most distant points of the ridges (in N = 28 – 29 cm)

3.Distantia trochanterica is the distance between two trochanters (in N = 30 – 31 cm)

4.Conjugata externa is the distance between the anterior top part pubic symphysis and suprasacral fossa (in N = 20 – 21 cm)

If all 4 sizes are N, you can deliver through the vaginal birth canal.

5.Conjugata diagonalis – S from the lower edge of the promontory to the symphysis (in N = 13 cm).

6. Conjugata vera - to determine it - 9 cm is subtracted from Conjugata externa (N = 20–9 = 11 cm).

7. Solovyov index – wrist circumference (in N = 13 – 18 cm). If the Solovyov index is less than 16 cm, then the bones of the skeleton are considered thin and Conjugata vera = Conjugata diagonalis - 1.5 cm. If the Solovyov index is 16 cm or more, then the pelvic capacity will be less (Conjugata vera = Conjugata diagonalis - 2 cm).

8. Lateral Kerner conjugate is the distance between the anterior superior and posterior superior awns of the same side (in N = 15 cm)

9.Height of the pubis – in N = 5 cm

10. Pelvic height – the distance between the ischial tuberosity and the pubic tubercle (in N = 9 cm)

11. The Michaelis rhombus is a rhombus whose vertices are the points: above - the suprasacral fossa, below - the upper edge of the gluteal fold, on the sides - the posterior superior iliac spines. Vertical size– 11 cm. Transverse size (Tridandani distance) – 10 cm.

12. Pelvic circumference – hip circumference in a non-pregnant state (at least 85 cm in N).

Objective methods for assessing fetal viability

Periods of fetal viability. From 28 to 37 weeks - the antenatal period - the period of fetal life during pregnancy.

The intranatal period is the period of life of the fetus during childbirth.

The postnatal period is divided into:

· Early – neonatal (first 7 days)

· Late – up to a month of life.

Childbirth. Premature - occurs from 28 to 37 weeks inclusive.

Urgent birth – 37 – 42 weeks.

Late birth – 43 weeks or more.

New criteria for live birth.

· Gestation period 22 – 27 weeks.

· Fruit weight 500 – 1000 g.

· Fruit length – 25 cm or more.

· There is one of the following signs: “heartbeat”, “spontaneous breathing”, “reflexes”, “pulsation of the umbilical cord”.

· If you lived 7 days of life.

Evaluation methods: 1) Non-invasive: determination of the level of α-fetoprotein. The study is carried out at 15–18 weeks. The level of fetoprotein in developmental defects is pathological. during pregnancy.

Ultrasound – 3 times – first visit ♀ – pregnancy diagnosis. 2 – at 16-

18 weeks assessment of growth rates, identifying development anomalies. 3 – 32–35 weeks. – condition, growth rate, term, position, weight of the fetus.

CTG, hysterography – continuous. simultaneous registering fetal heart rate and uterine tone.

2) Invasive: amniocentesis - puncture of amniotic fluid. The goal is cultivation, karyotyping. Chorionic biopsy – performed for karyotyping. Cordocentesis is a puncture of the fetal umbilical cord vessels to obtain its blood.

Hormonal function placenta

Placenta (P.) – “ children's place", iron internal secretion, cat. combines the function. system ♀and fetus. By the end of pregnancy, M = 500 g, d = 15–18 cm. The placenta is divided into the child's place, the maternal side, and the fetal side. Pl. – lobular organ (50–70 lobules). Ph-ii: gas exchange, endocrine function, protective, excretory. Maternal and fetal. blood flows do not communicate with each other.

Hormonal function: Pl. together with the fruit the image. single endocrine system(fetoplacental system). In Pl. implementation etc. synthesis, secretion, transformation of hormones of protein and steroid nature. Hormone production occurs in the trophoblast syncytium, decidual tissue. Pl hormones:

– placental lactogen (PL) – synthesized only in the placenta, enters the mother’s blood, maintains the function of the placenta.

– human chorionic gonadotropin(CG) – synthesized by the placenta, enters the mother’s blood, and participates in the mechanisms of fetal sex differentiation.

– prolactin – synthesis. placenta and decidular tissue. – plays a role in the image and surfactant.

From cholesterol, containing. in the mother's blood, in the placenta the image. pregnenolone and progesterone. Steroid hormones also include estrogens (estradiol, estrone, estriol). They cause hyperplasia and hypertrophy of the endometrium and myometrium.

Besides these, Pl. capable of production testosterone, CS, thyroxine, parathyroid hormone, calcitonin, serotonin, etc.

Intrapartum fetal protection

The influence of childbirth on the condition of the fetus: the fetus experiences increasing e hypoxia, hypercapnia, acidosis. Scrum accompanied. decreased uterine hemodynamics. Complicated labor aggravates intrauterine hypoxia. During childbirth, the condition of the fetus worsens in parallel with the pharmacological load, and some problems occur. not directly toxic. e-e, but indirect.

The meaning of the body position of a woman in labor: the position of pregnant women. presented on the back additional load on the cardiovascular system, and breathe. woman's system. For the outcome of labor and fetal condition, and then for n/r. The mother's position is of no small importance. The most physiological at time pushing - semi-sitting or sitting position, as well as positioning on the side. Childbirth in horizontal positive and more often accompanied. traumatization of the fetus and greater physiological blood loss.

Surgical delivery: All operations are character. traumatic for the fetus. At the same time, they help ↓ perinatal mortality. Application of A. forceps - can lead to birth trauma n/r. C-section- allows noun ↓ perinatal mortality. The timeliness of the operation is of decisive importance when it is possible to avoid protracted labor, a long anhydrous interval and the onset of fetal hypoxia. Bad influence Incorrectly chosen anesthesia and technical errors may have an impact on the fetus.

Features of care: after removal from the uterus, the baby is given the usual circle resuscitation measures, aerosol therapy is prescribed, often respiratory stimulants. and heart activities The frequency of complications reaches 10.9% (surgery during childbirth) and 1.7% (planned). The prognosis depends on the nature of A. pathology. The prognosis improves if the operation was performed as planned.

Birth trauma: a distinction is made between birth trauma, birth injuries and obstetric trauma. The first ones arose. under the doctor of physics. loads, properties. complicated giving birth The latter often more easily arose where there is an unfavorable background in the womb. development, aggravated by hypoxia during childbirth. For acute or chronic oblivion ♀, poisoning, pathological. during pregnancy, polyhydramnios, multiple pregnancies, post-term/premature pregnancy, rapid/ protracted labor, conditions are created for the occurrence of birth trauma.

Causes of intrauterine hypoxia and fetal death during childbirth: There are acute and chronic. fetal hypoxia: Chronic – 1. Maternal obstetrics (decompensated heart defects, diabetes, anemia, bronchopulmonary pathology, intoxication, infections). 2. Complications of pregnancy: late gestosis, postmaturity, polyhydramnios. 3. Fetal obstetrics: hemolytic. illness, generalization. IUI, developmental defects.

Acute – 1. Inadequate blood perfusion to the fetus from the maternal part of the placenta. 2. Placental abruption. 3. Clamping of the umbilical cord. 4. Inability to tolerate changes in oxygenation, connection. with contraction of the uterus.

Causes of fetal death during childbirth: 1. Fetal asphyxia. 2. Hemolytic. disease. 2. Birth injuries. 3. VUI. 4. Malformations of the fetus.

18. Perinatology, definitions, tasks

Perinatology (antenatal – from 28 weeks before the start of regular labor; intranatal – childbirth; postnatal – 7 days after birth). Objectives: 1. Prevention of pathology during childbirth.

2. Prevention of developmental defects.

3. Diagnosis of developmental defects.

4. Diagnosis and treatment of fetal distress.

In human intrauterine development, two periods are distinguished: embryonic and fetal. The embryonic period lasts from the moment of fertilization to 9 weeks of pregnancy, during this period the rudiments of all organs and systems are formed. The fetal period lasts from 9 weeks of pregnancy until the birth of the fetus.

During pregnancy, a mature fetus develops from a fertilized egg, capable of extrauterine existence. The maturity of a developed baby is judged by a combination of a number of signs: length, body weight, chest shape, location of the umbilical ring, condition of the skin and subcutaneous fat, condition of the ear and nasal cartilages, genitals, motor activity of the newborn.

The study of the shape and size of the fetal head is of particular importance in obstetrics. In the vast majority of births (96%), the head is the first to pass through the birth canal, making a series of sequential movements (turns).

The head, due to its density and size, experiences the greatest difficulty when passing through the birth canal. After the birth of the head, the birth canal is usually sufficiently prepared for the advancement of the torso and limbs of the fetus. The study of the head is important for the diagnosis and prognosis of labor: the location of the sutures and fontanelles is used to judge the mechanism of labor and its course.

The head of a mature fetus has a number of features. The facial bones of the fetus are firmly connected. The bones of the cranial part of the head are connected by fibrous membranes, which determine their known mobility and displacement in relation to each other. These fibrous membranes are called seams. The small spaces where seams intersect are called fontanelles. The bones in the area of ​​the fontanelles are also connected by a fibrous membrane. As the head passes through the birth canal, the sutures and fontanelles allow the bones of the skull to overlap each other. The fetal skull bones bend easily. These structural features of the bones give the fetal head plasticity, i.e. the ability to change shape, which is extremely important for its passage through the birth canal.

The fetal skull consists of two frontal, two parietal, two temporal and one occipital, main and ethmoid bones. In obstetrics, the following sutures are of particular importance:

Arrow seam(sutura sagitalis) passes between the parietal bones. In front, the seam passes into a large fontanelle, and in the back into a small fontanel.

Frontal suture(sutura frontalis) is located between the frontal bones; has the same direction as the arrow-shaped seam.

Coronal suture(sutura caronalis) connects the frontal bones with the parietal bones, runs perpendicular to the sagittal and frontal sutures.

Lambdoid(occipital) suture (sutura lambdoidea) connects the occipital bone to the parietal bones.

In the area where the sutures join, there are fontanelles (spaces free of bone tissue). The large and small fontanelles are of practical importance.

Large (anterior) fontanelle(fonticulus magnus s. anterior) is located at the junction of the sagittal, frontal and coronal sutures and has a diamond shape. Four sutures extend from the large fontanelle: anteriorly the frontal suture, posteriorly sagittal suture, and to the right and left the corresponding sections of the coronal suture.

Small (posterior) fontanel(fonticulus parvus, s posterior) is a small depression in which the sagittal and lambdoid sutures converge. The small fontanelle has a triangular shape; Three sutures extend from the small fontanel: sagittal suture anteriorly, and the corresponding sections of the lambdoid suture to the right and left.

There are four secondary fontanelles: two each on the right and left sides of the skull. Pterygoid fontanel(pterion) is located at the junction of the parietal, sphenoid, frontal and temporal bones. Star fontanel(asterion) is located at the junction of the parietal, temporal and occipital bones. These fontanelles have no special diagnostic value.

It is important to know the following bumps on the fetal head: occipital, two parietal, two frontal.

Dimensions of the head of a mature fetus:

1. Straight size(diameter fronto-occipitalis) - from the glabella to the occipital protuberance - equal to 12 cm. The circumference of the head in direct size (circumferentia fronto-occipitalis) - 34 cm.

2. Large oblique size(diameter mento-occipitalis) - from the chin to the occipital protuberance - is 13-13.5 cm. The circumference of the head according to this size (circumferentia mento-occipitalis) is 38-42 cm.

3. Small oblique size(diameter suboccipito-bregmaticus) - from the suboccipital fossa to the first corner of the large fontanel - is 9.5 cm. The circumference of the head corresponding to this size (circumferentia suboccipito-bregmatica) is 32 cm.

4. Medium oblique size(diameter suboccipitio-frontalis) – from the suboccipital fossa to the border of the scalp of the forehead – is 10 cm. The circumference of the head according to this size (circumferentia suboccipito-frontalis) is 33 cm.

5. Sheer or vertical size(diameter verticalis, s. trashelo-bregmaticus) - from the top of the crown (crown) to the sublingual region - is 9.5-10 cm. The circumference of the head corresponding to this size (cipcumferentia trashelo-bregmatica) is 32 cm.

6. Large cross size(diameter biparietalis) - the greatest distance between the parietal tubercles is 9.25-9.5 cm.

7. Small cross dimension(diameter bitemporalis) – the distance between the most distant points of the coronal suture is 8 cm.

Body dimensions:

1. Size of hangers– diameter of the shoulder girdle (diameter biacromialis) – equal to 12 cm. The circumference of the shoulder girdle is 35 cm.

2. Transverse size of the buttocks(diameter bisiliacalis) is 9-9.5 cm. Circumference is 28 cm.