Загрузил Bobojon Kurbaniyazov

02. Female pelvis. Fetus as object of delivery

Female pelvis. Fetus as the object of labor.
Obstetric terminology
doc. Stelmakh O.Y.
Female pelvis
Birth canal is divided into bone and soft parts to
bone belongs small pelvis and to soft - cervix, vagina,
muscle-fascial system of the pelvic floor.
Bone part of the pelvis
Female pelvis with obstetric considerations are divided into two
sections: the large and
small pelvis. The boundary between them passes through an
unmarked line (linea innominata). Large pelvis bounded on the
sides of the iliac wings,
back - the spine. Small pelvis formed in front
branches of the pubic bones and symphysis on each side - Part
constitute acetabular and ischial bones, behind the sacrum and coccyx.
During childbirth small pelvis as dense bone tunnel limits and
determines the size, shape and direction of the birth canal,
which fetus
passes, and has to adapt by changing their own configuration.
The main dimensions of the pelvis
Of all the methods of the pelvis
examination is essential it
Most internal pelvic sizes available for
measurement, so
usually measured by its external
dimensions and evaluate them about
Measurement of pelvic spend by
Usually measured four basic
dimensions of the pelvis: three
transverse and one direct.
The main dimensions of the pelvis
Distantia spinarum - the distance between
the upper anterior iliac spine bones. This
size is 25-26 cm;
Distantia cristarum - the distance between
the most distant points of wings iliac
bone. On average it is 28 cm
Distantia trochanterica - the distance
between the trochanter major of hip
bones. This size is 31 cm
The main dimensions of the pelvis
external conjugate – external
size of pelvis. End of
pelviometr set on
middle of the upper margin of
symphysis, the other end is
over the sacral fossa
contained between fifth
lumbar vertebra and the
beginning of the first sacral
vertebra. External conjugate
is 20 cm
The planes of the pelvis and their
In obstetric practice are important dimensions
of the pelvis, from
which depends on the course and outcomes
for both mother and fetus. But most sizes
pelvis can not be measured directly.
Great pelvis for childbirth substantial does not
matter, but in its
size may indirectly informates about the form
and size of the pelvis.
Pelvic cavity is the space between the walls,
which the top and bottom limited inlet and
outlet planes of the pelvis. It looks like a
cylinder. In pelvic cavity are four planes:inlet,
greatest dimention,
narrow part (midpelvis) and outlet.
The planes of the pelvis and their
The plane of the inlet of
a small pelvis bounded
behind promontory of
sacral bone, laterally
- arcuate lines iliac bone,
antioriorly- upper
margin of the pubic bone
and symphysis.
Small pelvis. The planes and the size of
the pelvis
At the pelvic inlet there are 4
sizes: antirior-postirior, transvers
and two oblique. Direct size distance from sacral promontory to
the point that most appear on the
inner surface of the upper margin
of the pubic symphysis - is true or
obstetric conjugate (conjugata
vera), which is 11 cm away from
promontory the to the middle of
the upper part of symphysis
anatomical conjugate to 0.3-0.5
cm greater than the obstetric .
Small pelvis. The planes and the size of
the pelvis
Dimensions plane of the pelvic inlet 1 –
antirior-posterior size, 2 - transverse
size, 3 - left oblique size, 4 - right
oblique size
The transverse size of the distance
between the inniminata lines is 13 cm
Two oblique, right and left, which have
12 cm Right oblique size goes from the
right iliac-sacral junction to the left
eminentia iliopubis. Left oblique sizefrom the left iliacsacrum junction to the
right eminentia iliopubis.
Small pelvis. The planes and the size of
the pelvis
Plane of widest part of the
pelvic cavity has the
following limits:
front - a middle inner
surface of the pubic
symphysis, laterally - mid
acetabulum hollow, back the place II and III sacral
vertebrae. Direct and
transverse dimensions of
the plane are equal to
12,5 cm
Small pelvis. The planes and the size of
the pelvis
The plane of the narrow part
of the pelvic cavity is limited
to the lower edge of the
front pubic symphysis,
laterally – ishial spine
behind - sacro-coccygeal
joints. Direct size is 11-11,5
cm transvers - 10.5 cm
Small pelvis. The planes and the size of
the pelvis
Plane of pelvic outlet has the
following borders: anteriorlylower margin of the pubic
symphysis, laterally –tuber
ischii, posteriorly- the tip of the
coccyx. Direct size - 9.5 cm,
and the transvers - 11.5 cm
The line connecting the centers
of all direct sizes of pelvis,
called the main axis of the
Measuring the size of the pelvis
Diagonal conjugate measured during
vaginal examination from the lower
margin of pubis to promontory. Normally,
this distance is 12,5-13 cm for the
determination of the real conjugates of
bias should be deducted 1.5-2 cm
Index Soloviev - average circumference
of wrist is 14 cm
Rhombus of Michaelis - upper angle
contained hollow under the spinous
processes of the 5 lumbar vertebrae
Lateral angles correspond posteriorsuperior iliac spine, lower- top sacrum. In
women with a normal pelvis it has the
correct form, approaching the square, its
dimensions are 10.11 cm, height of the
upper triangle 3-3.5 cm
Fetus as the object of labor
From all parts of the mature fetus most interesting
head, because of the following reasons: 1) head
has the big circumference and dense part of
thefetus, which can withstand the greatest
resistance from the birth canal and puts most
pressure on them that determines the outcome of
labor, 2) depending on the density and mobility of
the cranial bones is greatly damage the birth
canal of the mother and the fetus, and 3) the
head of the fetus has a large number of cognitive
items, which helps in diagnosing insertion and
promotion in the bones of the pelvis.
At the head of the fetus can distinguish two parts
(Fig. 1): a relatively small front: lower jaw (1),
maxilla (2) and very voluminous - brain. The latter
consists of seven bones: two frontal (3), two
parietal(4), one occipital (5), two temporal (6).
Fetus as the object of labor
Sutures and fontanelles skull
newborn (seen from above):
1 - frontal suture, 2 - coronal suture
3 - sagittal (sagittal) suture 4 occipital suture, 5 - Small fontanel 6
- large fontanel
All bony parts are interconnected
fibrous membranes, allowing the
process of childbirth crossbones go
one after another, thus reducing the
size of the head
Fetus as the object of labor
These fibrous membrane called
sutures There are the following joints:
1) frontal sutura (sutura frontalis); 2)
coronal suture (sutura coronaria),
connecting on each side of the frontal
and parietal bones, and 3) sagittal
(sagittal) suture (sutura sagittalis),
combining two parietal bone, 4) or
lyambdoid occipital suture (sutura
lambdoidea), connecting occipital
bone with the parietal, 5) temporal
suture (sutura temporalis),
connecting on each side of the
parietal temporal bone (mostly).
Fetus as the object of labor
Fibrous membrane at the
intersections of joints called
fontanelles. There are two main
fontanel and two pairs of
secondary. The main fontanelles
include large and small fontanel
Large fontanel (fonticulus magnus
s. Bregmaticus) located at the
intersection of coronary, windshield
and sagital suture and a diamond
shape. Acute angle of the diamond
sent to the forehead, and - back. It
is easily determined by finger.
Small (5) fontanel is located at the
intersection sagital and occipital
sutures. Unlike large, small
fontanel poorly defined because it
is already ripe fetus filled bone.
Fetus as the object of labor
At the head term fetus can distinguish the
following dimensions and perimeter :
1. vertical size (diameter sublinguobregmatica) distance from the hyoid bone
to the middle of the large fontanel, is
equal to 9.5 cm on the contours of the
head, measured through these points
vertical size, (circumferentia sublinguobregmatica) - 32 cm
2. Large oblique size (diameter mentooccipitalis) - from the chin to the farthest
point of the neck, length - 13 cm from the
perimeter (circumferentia mentooccipitalis) - 41 cm
Fetus as the object of labor
8. Direct size (diameter fronto-occipitalis) - from
the nose to the occipital hill, length - 12 cm by
34 cm contours of equal
7. Average oblique size (diameter suboccipitofrontalis) - from suboccipital fossa to the
anterior border of the scalp, length of 10 cm,
and contours (circumferentia suboccipitofrontalis) - 33 cm
6. Small oblique size (diameter suboccipitobregmatica) - from the middle suboccipital
fossa large fontanel, length - 9.5 cm, and
circumference suboccipito-bregmatica - 32 cm
Fetus as the object of labor
7. Small transverse size (diameter
bitemporalis) - the distance between the
most distant points of the coronal
suture, - 8 cm
8. Large transverse size (diameter
biparietalis) - the distance between the
parietal bones, length - 9.5 cm
Circumferences of shoulders is
34cm (12cm), circumferences of
pelvic part is 28cm (9,5cm).
Fetus as the object of labor
The transverse size of the buttocks
(distantia bisiliacalis) length and 9.5 cm in
perimeter: an incomplete presentation
buttocks - 32 cm , with full foot previa - 28
cm , with full presentation buttocks - 34 cm
11. Contours (in cm) newborn body in full
foot presentation: shoulder with handles
(34) buttocks (28).
12. Contours (in cm) newborn body in
complete breech presentation: shoulder
(34); buttocks with legs (34).
Obstetric terminology
definitions of "fetal lie,
"position", "view",
Accurate knowledge of the
position of the fetus in the
uterus, is of great importance
for practical obstetrics. It is
achieved by the examination
of women in late pregnancy,
when you can set fetus
habitus, its lie , presentation,
position and variety.
Obstetric terminology
Attitude of fetus (habitus) - is the ratio
of the limbs of the fetus and the head
to his body. In the most favorable
habitus - curved spine, resulting in
back arched outwards, head bent, chin
close to the chest. The legs are flexed
at the hip and knee joints, intersect
and pinned to the lower abdomen.
Handles are flexed at the elbows and
intersect on his chest.
Obstetric terminology
Fetal lie (situs) - is the ratio of the axis
of the fetus to the axis of the uterus. The
axis of the fetus - a line that passes
through the neck and buttocks. Can
meet the following options for the of the
fetus lie :
fetal axis coincides with the uterus longitudinal lie (situs longitudinalis) occurs in 99% of cases;
fetal axis intersects the uterus transverse (situs transversus) or oblique
fetal lie (situs obliguus).
Obstetric terminology
Position of the fetus (positio) - is the
ratio of the fetus back to the left (I
position 2/3 cases) or right (second
position, 1/3 of cases) the uterine wall.
In transverse position of the fetus
position is determined by the placement
Type of position (visus) - the ratio of the
fetus back to the front or back wall of
the uterus. In the front form the back of
the fetus is facing the front wall of the
uterus, at the back of the form - to the
back wall of the uterus.
Fetal presentation (presentatio) - is the
ratio of the lowest placed a large part of
the fetus to enter the pelvis (main or
Fetal head station
-2 (fixed to pelvic inlet)
-1(small segment of fetal
head in pelvic inlet)
0 (large segment of fetal
head in pelvic inlet)
+1 (fetal head in plane of
greatest dimension)
+2 (fetal head in plane of
least dimension)
+3 (fetal head in the
pelvic outlet
Anamnesis women
When taking history clarifies the following issues: 1)
Passport part: last name, first name, age,
pregnancy, occupation, address, phone, and 2)
carried diseases: childhood, adulthood, pregnancy,
and 3) family history, and 4) working and living
conditions, and 5) special history: menstrual, sexual,
reproductive and secretory functions, 6) the
occurrence of pregnancy.
Overview pregnant
During the general examination pay attention
to height, body structure, completeness,
condition of skin, shape of the abdomen,
development of breasts and nipples, pubic
hair growth
External measurement
In order to have an idea about the
size of the fetus, measure the size of
the abdomen measuring tape: sight
abdoman. In the supine position at
the navel at the end of pregnancy,
this woman is 110 cm and the height
stoyanyya uterus above the pubis 37 cm to determine the mass of fetal
abdominal perimeter must be
multiplied by the height of standing
uterus (110 cm x 37 cm = 4070 g).
External examination
External examination -LeopoldLevitsky manuvers:
The first external method
Obstetrician sits to the right of the
pregnant woman, facing her. Palmar
surface of the hand puts the fundus of
the uterus, is trying to bring together
the nail phalanges. This reception
determine the height of standing and
form the uterus (normal, saddle, twohorned), the part of fetus that is at its
fundus .
The second external method..
The doctor pulls the two arms of
the uterus on the side wall of the
abdomen and one by one, then
another, then another hand,
carries palpation. If it finds one
side smooth, wide, curved surface
- back (left - the first position to
the right - the second position),
which is facing forward (front
view) or back (posterior view.
The third external method .
Obstetrician palm and thumb and
other four fingers of his right hand
covers and squeezes the fetus
placed above the entrance to a
smallpelvis, attempts to displace it
to the right or left side, verifying
the presence or absence of
symptoms ballotment. If above the
pubic joints palpated soft and
broad, it can be suspected breech
presentation, and if solid and
rounded -cefalic .
Fourth external method is performed as
follows: Obstetrician stands face to legs
bent at the knees pregnant tips and
palmar surfaces of the fingers of both
hands gently and gradually slides along
the side of the head down, gets
between her and the plane door in a
small bowl and returns back up,
checking the results. In transverse
position of the fetus peredlezhascha
part on the pubic joints not palpable
and fingers freely agree among
themselves high above the vagina.
When cephalic this method allows to
determine the place of accommodation.
If peredlezhascha part above the
entrance to the small pelvis, the fingers
of both hands freely converge under it,
and when returning back - apart
Vaginal examination
Vaginal examination is required in the
following cases: the first - at the time of
admission to the hospital pregnant, the
second - after the discharge of amniotic fluid
or early labor activity and the third - when
changing obstetric situation; fourth - early in
the second stage of labor
Vaginal examination provides information
on the status of the genital tract before birth,
there exostosis, bone tumors, deformities of
the pelvis, dynamic opening of the cervix,
the presence of amniotic mamrane, the
mechanism of insertion and passage of the
birth canal presenting part.
Estimation of diagonal conjugate
Ultrasonic dating of the pregnancy and
an ultrasonic fetal survey to detect gross
abnormalities have been recommended
in some clinics as a routine part of early
prenatal care. Routine ultrasonography
is most cost – effective in patients in
whom the date of the last menstrual
period is uncertain and in patients with a
family history of congenital anomalies.
Considerable individualization should be
exercised in making the decision to order
this evaluation. If ultrasonography is
performed, it is most informative between
11-13 and18-20 weeks.
Auscultation. In cephalic presentation,
the point of maximal intensity of fetal
heart sounds is usually midway between
the maternal umbilicus and the
anterior-superior spine of her ilium.