PREGNANCY AND LABOR AT FETAL nMALPRESENTATIONS AND ABNORMAL PELVIS
Planes and Diameters of nthe Normal Pelvis
The pelvis has four nimaginary planes:
1– plane of the pelvic ninlet,
2 – plane of greatest npelvic dimensions,
3 – the plane of the nmidpelvis (least pelvic dimensions),
4 – the plane of the npelvic outlet.
Pelvic inlet is bounded nposteriorly by the promontory, laterally by the linea terminalis, and nanteriorly by the horizontal rami of the pubic bones and symphysis pubis. Four ndiameters of pelvic inlet are described: the anterposterior (11cm), the ntransverse (13cm), and two obliques (12 cm from left or right sacroiliac synchondroses to the iliopectineal eminence on the opposite side of the pelvis).
The plane of greatest npelvic dimension extends from the middle of the posterior surface of the nsymphysis pubis through the ischial bones over the middle of the acetabulum to nthe junction of second and third sacral vertebrae. Its anteroposterior and ntransverse diameters are 12,5 cm.
The midpelvis at the level nof the ischial spines is particular importance following engagement of the nfetus head in obstructed labor. The transverse diameter (interspinous) is 10,5 cm and anteroposterior is 11cm.
Pelvic outlet has two ndiameters: anteroposterior extends from the lower margin of the symphysis pubis nto the tip of the coccys (9,5cm) and transverse diameter between the inner nedges of the ischial tuberosities 11,5 cm.
The maiexternal pelvic sizes:
D. Spinarun – distance betweeanterior superior iliac spines from both sides. It has 25-26 cm.
D. nCristarum n– distance between iliac crista from both sides. It is 28-29 cm.
D. nTrochanterica – distance between trochanter majors from both sides. It has 31-32 cm.
C. Externa – distance betweemidpoint of superior surface of the symphysis pubis and suprasacralis fossa.
Michael’s’ nrhomb. It nhas 4 angles. The upper angle is located in the suprasacralis fossa. The lower nangle is situated in the apex of coccyx, and laterally angles are situated ithe posterior superior iliac spines. In the women with normal pelvis rhomb has nregular form. It vertical diameter has 11 cm, and horizontal diameter is 10 cm.
Solovjov’ nindex. It nis estimated by the circumference of radiocarpal joint. It has 14-16 cm and indicates into bones’ pelvic thickness.
The nadditional external pelvic sizes:
Lateral nconjugate n–is a distance between the anterior superior iliac spine and posterior superior niliac spine of the same iliac bone. It has 14.5-16 cm.
Oblique nconjugate n–is a distance between the right anterior superior iliac spine to the left nposterior superior iliac spine. It has 14.5-16 cm.
Anteroposterior ndiameter of the pelvic outlet is a distance between the lower par4t of symphysis npubis and apex of the coccyx. It has 9.5 cm.
Transverse ndiameter of the pelvic outlet is a distance between the posterior portions of the ishial ntuberosities. It has 11.5 cm.
The maiinternal pelvic sizes:
The widest nanteroposterior diameter of the pelvic inlet is called obstetric conjugate. nIt runs from the upper midpoint of the symphysis to the promontorium. It has 11 cm. It is one of the most important pelvic dimension.
Indirect nways of true conjugate estimation:
1. An estimate nof the obstetric conjugate is made by determining of the diagonal conjugate. nDuring a vaginal examination, the physician attempts to reach the sacral npromontory with the middle finger of the examining hand. The index finger of nthe free hand marks the point where the lower border of the pubic syphysis nimpinges on the examining hand proximal to the metacarpophalangeal joint of the nindex finger. This measurement, the diagonal conjugate, usually exceeds the nobstetric conjugate by 1.5 to 2 cm.
2. External nconjugate exceeds the obstetric conjugate by 9 cm.
3. Vertical ndimension of Michael’s’ rhomb equal obstetric conjugate.
CONTRACTED nPELVIS
Anatomically contracted pelvis is characterized by shortening of nall or one diameters of the true pelvis into 1,5 – 2 cm and more.
Clinically or functional contracted pelvis is usually defined as npelvis with normal dimensions, but vaginally delivery is impossible due to n“fetopelvic disproportion”.
The maicauses of “cephalopelvic disproportion” are fetal macrosomia, postdate npregnancy, uterine inertia, fetal malpresentation, especially fetal head nextension – sinciput vertex, brow, face anterior position.
Clinic signs of clinically contracted pelvis:
1. Head is arrested in the pelvic inlet (absence of fetal descending icomplete cervical dilation and adequate uterine contractions).
2. Uterine contractions abnormality.
3. Positive Vasten’ sign (if disproportion between fetal head and nsymphisis pubis is prominent – Vasten’ sign is positive, if disproportiobetween fetal head and symphisis pubis is absent – Vasten’ sign is negative).
4. Signs of urinary bladder compression.
5. Edema of the cervix, and vaginal walls, productions of fistulas.
When the presenting part is firmly wedged into the pelvic inlet but does nnot advance for a considerable time, portions of the birth canal lying betweeit and the pelvic wall may be subjected to excessive pressure. As a circulatiois impaired, the resulting necrosis may become manifest several days after ndelivery by the appearance of vesicovaginal, vesicocervical, or rectovaginal nfistulas.
6. Danger of uterine rupture.
When the disproportion between the head and the pelvis is so pronounced nthat engagement and descent do not occur, the lower uterine segment becomes nincreasingly stretched, and the danger of its rupture becomes imminent. In such ncases,. a pathologic contractile ring may develop and can be felt as a ntransverse or oblique ridge extending across the uterus somewhere between the nsymphysis and the umbilicus. Whenever this condition is noted, prompt cesareadelivery must be employed to terminate labor and prevent rupture of the uterus. n
7. Pushing occurs if fetal head is situated in the plane of inlet.
Management in the case of clinically contracted pelvis – only cesareasection.
Pelvic classificatioaccording to form of contractions:
1. Often occurred
· ngenerally contracted pelvis;
· nflat pelvis: simple flat pelvis, flat rachitic pelvis, ngenerally contracted flat pelvis.
Generally ncontracted pelvis is characterized by diminution of all true pelvic diameters n(anteroposterior, transverse, and oblique) into 1-2 cm. Subpubic arch is narrow. Average sizes of the pelvis are: D. spinarum – 23cm, D. cristarum – 26 cm. D. trochanterica – 29 cm, C. externa – 18 cm, C. diagonalis – 11 cm, C. vera – 9 cm.
Course of nlabor:
· nprolongation of labor;
· nconsiderable fetal head flexion thanks to which it is nelongated in the ocipitofrontal diameter (dolichocepaly);
· nposterior fontanel is situated into the axis of pelvis;
· nconsiderable molding of the fetal head. Caput succedaneum is nformed in the area of posterior fontanel;
· nwith increasing narrowing of the pubic arch, the occiput ncannot emerge directly beneath the symphysis pubis but is forced increasingly nfarther down upon the ishiopubic rami. It may play an important part in the nproduction of perineal tears.
Management nof labor. nVaginally delivery is possible.
Flat pelvis n – is nusually defined as diminution of anteroposterior diameters of true pelvis, ntransverse and oblique diameters are normal.
Simple flat npelvis is ndefined as shortening of anteroposterior diameters at all levels of true npelvis, as a result of this sacrum is inclined anteriorly to pubis.
Average sizes nof the pelvis are: D. spinarum – 26cm, D. cristarum – 29 cm. D. trochanterica – 31 cm, C. externa – 18 cm, C. diagonalis – 11 cm, C. vera – 9 cm.
Course of nlabor:
· nprolongation of labor;
· nsagittal suture of the fetal head arresting in the transverse ndiameter of the plane of inlet;
· nfetal head extension until bitemporal fetal head diameter nwould be situated in the anteroposterior diameter of the plane of inlet;
· nanterior fontanel is the leading point of the fetal head n(lowermost situated);
· nasynclitism should be presented (anterior or posterior);
· nconsiderable molding of the fetal head. Caput succedaneum is nformed in the area of anterior fontanel.
Management nof labor. Ithe case of posterior asynclitism vaginal delivery is impossible thanks to nengagement of posterior shoulder into the plane of inlet. Cesarean sectioshould be performed.
Flat nrachitic pelvis – is characterized by some peculiarities:
1. True conjugate is shortened.
2. Sidewalls tend to nconverge, as result of this D. spinarum and D. cristarum are equal.
3. Additional promontorium nmay be presented between 1 and 2 vertebrae of sacrum
4. Subpubic arch is shallow nand wide
5. Top of the sacrum is nsituated posteriorly that’s why dimensions of the pelvic outlet are normal or neven increased.
Average sizes nof the pelvis are: D. spinarum – 26cm, D. cristarum – 26 cm., D. trochanterica – 31 cm, C. externa – 17 cm, C. diagonalis – 10 cm, C. vera – 8 cm.
Course of nlabor is the nsame as in the simple flat pelvis. But thanks to normal or even increased nanteroposterior size of pelvic outlet perineal tears as result of quick second nstage labor may be presented.
Management nof labor. nVaginal delivery is possible.
Generally ncontracted flat pelvis is characterized by combination of the signs of generally ncontracted and flat pelvis.
Average sizes nof the pelvis are: D. spinarum – 24cm, D. cristarum – 25 cm., D. trochanterica – 28 cm, C. externa – 16 cm, C. diagonalis – 9 cm, C. vera – 7 cm.
Course of nlabor depends nfrom predominance of kind of pelvis contraction.
Management nof labor. Cesareasection is the method of choice.
2. Rare noccurred contracted pelvis: obliquely contracted pelvis, obliquely ndislocated pelvis, transverse contracted pelvis, osteomalacic pelvis, nfunnel-shaped pelvis, spondylolisthetic pelvis, contracted pelvis as a result nof exostosis and bone tumors. Management of labor. Cesarean sectioshould be performed in all of these types of pelvis.
Pelvic classificatioaccording to degree of contraction:
Four degrees of pelvic contractions should be distinguished:
I degree – True conjugate is 11-9 cm. Vaginal delivery is possible.
II degree – True conjugate is 9-7,5 cm. Vaginal delivery is possible.
III degree – True conjugate is 7,5 – 5,5 cm Cesarean section is performed.
IV – degree – True conjugate is 5.5 cm. Cesarean section is performed.
BREECH nPRESENTATIONS
There is a nfundamental difference between delivery in cephalic and breech presentation. nWith a cephalic presentation, once the head is delivered, typically the rest of nthe body follows without difficulty. With a breech, however, successively nlarger or, in case of the head, very much less compressible parts of the fetus nare born.
Spontaneous ncomplete expulsion of the fetus that presents as a breech, as described below, nis seldom successfully accomplished. As the rule, either cesarean section of nvaginal delivery that requires skilled participation by the obstetrician is nessential for a favorable outcome.
Etiology. Breeches are much more ncommon at the end of the second trimester of pregnancy than at or near term. nFactors other than prematurity that arrear to predispose to breech presentatioinclude uterine relaxation association with great parity, multiple fetuses, nhydramnion, hydrocephalus, anencephalus, previous breech delivery, uterine nanomalies, and tumors.
Classification. The varying relations nbetween the lower extremities and buttocks of the fetus in breech presentatioform the categories of frank breech, complete breech, incomplete breech npresentation, footling and kneeling presentation.
In frank nbreech presentation the lower extremities are flexed at the hips and extended nat the knees and thus the feet lie in close proximity to the head.
In complete nbreech presentation the lower extremities are flexed at the hips and at the nknees.
In incomplete nbreech presentation the lower extremities are flexed at the hips and at the nknees and the one or both feet lie below the breech.
In footling npresentation the feet lies lower than breech.
The kneeling npresentation is the especial form of the breech, when the fetal knees are lower nthan the breech.
Diagnosis. The diagnosis of the breech presentation may be making with the help of nexternal and internal obstetrics investigation. With the first maneuver of the external nexamination we identify the hard, round, ballottable fetal head to occupy nhe fundus of the uterus. The second maneuver indicates the back to be on one nside of the abdomen and the small parts in other. On the third maneuver the nbreech is movable above the pelvic inlet. The heart sounds of the fetus are nusually heard loudest slightly above the umbilicus.
Vaginal examination. In frank breech presentation only buttocks and its ncharacteristics components (both ischial tuberosities, the sacrum, the anus, nthe external genitalia) are usually palpable. In incomplete breech presentatiothe buttocks and the feet may be palpated. In footling the fetal feet are lower nthan buttocks.
Biomechanism nof labor in breech presentation.
I moment – the internal breech rotation. The breech nrotates and the fetal intertrochanteric diameter from one of oblique size of nthe pelvic inlet to anteteroposterior size of the pelvic outlet.
II moment – nthe lateral flexion of the body. The anterior hip is stemmed against the pubic narc. By lateral flexion of the fetal body the posterior hip is forced over the nanterior margin of the perineum. Then anterior hip is born.
III moment – the internal shoulders rotation. After nthe birth of the breech, there is the slight external rotation as a result of nthe descends and rotations of the shoulders. The shoulders rotates on the npelvic floor and diameter biacromialis occupies anteroposterior diameter of the npelvic outlet.
IV moment – the lateral flexion the body in the nthoraco-brachial part. The shoulders are born.
V moment – the internal rotation of the head. The nrotation begins when the fetal head descends from the plane of greatest pelvic ndimensions to the least pelvic dimensions (midpelvis). The rotation is complete nwhen the head reaches the pelvic floor, the sagittal suture is in the nanteroposterior diameter of the pelvic outlet and the small fontanel is under nthe symphysis.
VI moment – the flexion of the fetal head. The head nfixes with its fossa suboccipitalis to the inferior margin of symphysis pubis nand flexes. The face, forehead, vertex, and occiput are born.
The manual aids in breech presentations.
The manual aid by Tsovyanov I in frank nbreech presentations.
The aim of the manual aid: to prepare the nmaternal ways to the delivery of the head and shoulders and to keep the normal nattitude of the fetus.
In the frank breech presentation the fetus extremities nare flexed at the hips and extended at the knees and thus the feet lie in close nproximity to the head. The circumference of the thorax with the crossing on it narms and legs is larger than circumference of the head and the after-coming nhead deliveries easily.
The technique. The aid begins after the delivery of the buttocks. nThe obstetrician’s hands are applied over the buttocks, the thumbs placed othe fetus sacrum and other fingers on the legs. The doctor gently supports the nlegs to avoid its flexion. If the normal attitude of the fetus is keeping the nhead deliveries easy.
The classic manual aid on the labor in complete and nincomplete breech presentation.
The aim of the classic manual aid: to help of the shoulders and the head ndelivery.
The classic manual aid begins when the lower angular nof the anterior scapula became visible. There are 4 moments of the classic nmanual aid.
I moment – the delivery of the posterior arm. The nposterior shoulder must be delivered first. The feet are grasped in one hand nand drawn upward over the groin of the mother toward which the ventral surface nof the fetus is directed; in this manner, leverage is exerted upon the nposterior shoulder, which slides out over the perineal margin, usually followed nby the arm and hand.
II and III moment – the external trunk rotation and nthe freeing the posterior arm. The aim of this moment is the reverse of the nanterior shoulder to the sacrum and the delivery of second arm. The nobstetrician applies his hand on the lateral sides of the fetus trunk and nrotates it. The direction of the movement must be in this way: the occiput must ngo under the symphysis pubis. When the posterior shoulder and arm appears at nthe vulva the doctor put two fingers into the vagina, the fingers passed along nthe humorous until the elbow is reached. The fingers are now used to splint the narm, which is swept downward and delivered through the vulva.
IV moment – the freeing of the head. After the nshoulder are born, the head usually occupies an oblique diameter of the pelvic nwith the occiput directed anteriorly. The fetal head may then be extracted by nthe method of Mauriceau-Levret. Employing the Mauriceau-Levre maneuver to help nflex the head, the doctor’s middle finger of one hand are applied into the nfetal mouth, while the fetal body rests upon the palm of the hand and fore arm, nwhich is straddled the fetal legs. Two fingers of the operator’s other hand are nthen hooked over the fetal neck and grasping the shoulders, downward tractiois applied until the suboccipital region appears under the symphysis. The body nof the fetus is then elevated toward the mother abdomen, and the mouth, nose, nbrow and the occiput emerge over the perineum. Gentle traction should be nexerted by the fingers over the shoulders.
The manual aid by Tsovyanov II in footling npresentations.
The aim of the manual aid: To perform the footling presentation to nthe incomplete breech and to prepare the maternal ways to the delivery of the nhead and shoulders.
The doctor covers the area of the vulva with the nsterile napkin and puts up resistance to the delivery of the feet. The feet are nflexing and the footling presentation becomes incomplete breech presentation. nThan the delivery manage as in incomplete breech presentation.
The management of the breech delivery.
1. To try the minimize infant nmortality and morbidity, cesarean section is preferred.
Favorable factors for breech delivery – multiple pregnancy, nsecond fetus is in breech.
Indications nfor breech extraction:
· nThe requirement for instant vaginal delivery;
· nCases in which one is already committed to vaginal delivery nand cesarean section is not appropriate or feasible (maternal indications – npreeclampsia, hard heart and pulmonal diseases, cord prolapse; fetus nindications – acute hypoxia);
· nThe breech extraction is committed after the operation.
The nconditions for breech extraction:
· nThe cervix must be completely dilated and retracted high ithe pelvis (although the breech – especially in footling presentation – may npass the cervix without incident, the shoulders or head will surely be trapped nby incompletely dilated cervix);
· nThe uterus must be relaxed;
· nThe normal fetopelvic proportion;
· nThe rupture of membranes.
The ntechniques for breech extraction.
The ntechniques for the operation of extraction fetus on the two legs.
During total breech nextraction, the obstetrician’s entire hand should be introduced through nthe vagina and both feet of the fetus grasped. The ankles are held with the nsecond finger lying between them. The feet are then brought down the vagina, nand gentle traction applied until they appear at the vulva. Now both feet are ngrasped and pulled through the vulva. As the legs commence to emerge through nthe vulva, they should be wrapped in a sterile towel to obtain a firmer grasp, nfor the vernix caseosa renders them slippery and difficult to hold. Downward ngentle traction is then continued.
As the legs emerge, nsuccessively higher portion are grasped, first the calves and later the thighs. nWhen the breech appears at the vulva, gentle traction is applied until the nhips are delivered. As the buttocks emerge, the back of the infant usually nrotates to the anterior. The thumbs of the operator are then placed over the nsacrum and gentle downward traction is continued until the costal margins, and nthen, the scapulas become visible. The back of the infant tends to turn spontaneously toward the nside of the mother to which it originally directed. If turning does not occur, nslight rotation should be added to the traction, with the object of bringing nthe bisacromial diameter of the fetus in the antero-posterior diameter of the npelvic outlet.
There are two methods of delivery nof the shoulders: with the scapulas visible, the trunk is rotated isuch a way that the anterior shoulder and the arm appear at the vulva and caeasily be released and delivered first. The operator is shown rotating the ntrunk of the fetus counterclockwise to deliver the right shoulder and arm. The nbody of the fetus is then rotated in the reverse direction to deliver the other nshoulder and arm. If trunk rotation is unsuccessful, the posterior shoulder nmust be delivered first. The feet are grasped in one hand and drawn upward nover the groin of the mother toward which the ventral surface of the fetus is ndirected; in this manner, leverage is exerted upon the posterior shoulder, nwhich slides out over the perineal margin, usually followed by the arm and nhand. Then, by depressing the body of the fetus, the anterior shoulders emerges nbeneath the pubic arch, and the arm and hand usually follow spontaneously. nThereafter, the back tends to rotate spontaneously in the direction of the nmother’s symphysis. If upward rotation fails to occur, it is effected by manual nrotation of the body.
Delivery of the head may then be accomplished.
After the shoulders are nborn, the head usually occupies an oblique diameter of the pelvis with the chidirected posteriorly. The fetal head may then be extracted either with nforceps, which is the method preferred by many obstetricians, or by so-called nMauriceau maneuver.
Employing the Mauriceau nmaneuver to help flex the head, the operator’s index and middle finger of the nhand are applied over the maxilla, while the fetal body rests upon the palm of nthe hand and forearm, which is straddled by the fetal legs. Two fingers of the noperator’s other hand are then hooked over the fetal neck, and grasping the nshoulders, downward traction is applied until the suboccipital region appears nunder the symphysis. The body of the fetus is then elevated toward the mother’s nabdomen, and the mouth, nose, brow and eventually the occiput emerge nsuccessively over the perineum. Gentle traction should be exerted by the nfingers over the shoulders. At the same time, suprapubic pressure, nappropriately applied by an assistant.
The transverse lie is the condition when the long axis of nthe fetus is approximately perpendicular to that of the uterus. When it forms nan acute angle, an oblique lie results. An oblique lie is nusually only transitory, however, for either a longitudinal or transverse lie ncommonly results when labor supervenes. For this reason, the oblique lie is ntermed unstable lie.
An unstable nlie is one in which the presenting part alters from week to week. It may be neither a transverse or oblique lie or possibly a breech presentation. These are nrelatively uncommon events but are found in association with the following nconditions:
1. nGrand multipara. This is by far the commonest factor, due to the lax uterine nand abdominal walls, which prevent the splinting effect found in women with nlesser parity.
2. Polyhydramnios. The volume of fluid distends the uterus nand allows the fetus to swim like a goldfish in a bowl — often taking up aoblique or transverse lie.
3. nPrematurity. Here there is a relative excess of fluid to the fetus. If preterm nlabour occurs, the fetus may be found to have a transverse lie.
4. Subseptate nuterus. The septum prevents the fetus from turning in utero.
5. Pelvic ntumors such as fibroids and ovarian cysts may not only prevent the lower pole nfrom engaging, but cause it to take up a transverse lie.
6. nPlacenta praevia. This usually prevents engagement of the presenting part. nBecause of this it may present with the fetus in an oblique or transverse lie.
7. Multiple npregnancies may present with a transverse lie. If this does occur, it is more ncommon in the second twin.
Diagnosis nof the transverse and oblique lies:
1. The external ninspection shows than the abdomen is unusually wide from side to side, whereas nthe fundus of the uterus extends scarcely above the umbilicus.
2. Opalpation, with the first maneuver no fetal pole is detected in the fundus.
3. On the nsecond maneuver, a ballottable head is found in one side of uterus and the nbreech in other.
4. The third nand fourth maneuvers are negative unless labor is well advanced and the nshoulder has become impacted in the pelvis.
5. When the nfetal head is situated in the left side of the uterus the first position of the nfetus is identified. When the fetal head is situated in the right side of the nuterus the second position is recognized.
6. On vaginal nexamination, in the early stages of labor, the side of the thorax, if it can be nreached, may be recognized above the pelvic inlet. When the dilatation is nfurther advanced, the scapula and the clavicle are distinguished on opposite nsides of the thorax. Later in the labor, the shoulder becomes tightly wedged ithe pelvic canal, and a hand and arm frequently prolapse into the vagina and nthrough the vulva.
Management nof transverse and oblique lie. It is not uncommon for the fetus to have a transverse nlie until about the 32nd week of pregnancy. If the transverse lie persists nafter this time a cause should be determined. An ultrasound examination should nbe done to exclude placenta praevia, ovarian tumor or fibroid and if either of nthese conditions are present an elective cesarean section should be performed nat 38-39 weeks of gestation. The ultrasound is also used for identifying twins nand a subseptate uterus, whilst a vaginal examination will confirm a pelvic ntumor.
The main risk nof a transverse or oblique lie is in association with preterm rupture of the nmembranes and cord prolapse. When diagnosed the state of the cervix should be nchecked. If the cervix is dilated, the patient should be admitted to hospital. nIf, however, the cervix is closed and the membranes are intact the patient may nbe reviewed on a regular basis. If no easily identifiable cause is found, attempted nexternal cephalic version can be made after 34 weeks. In grand multipara npatients, the fetus will usually turn easily but will often swing back to aabnormal lie. If the abnormal lie persists or constantly reoccurs, the womashould be admitted to hospital by the 38th week. If external version is nsuccessful at this stage and the patient’s cervix is favorable then artificial nrupture of the membrane can be performed with the head held over the pelvic nbrim and an oxytocin drip commenced to augment uterine activity. If the ncephalic presentation is maintained, labor may be allowed to continue.
Management of transverse or oblique in labor – cesarean section must be nperformed.
Complications nof a transverse lie. If a mother goes into labor with a transverse or oblique lie, nseveral catastrophes may occur. Because this occurs more commonly imultiparous women and their uterine activity is often much stronger, rupture nof the uterus is more likely. When the membranes rupture there is a greatly increased ndanger of cord prolapse, prolapse of the arm- persistent transverse lie occur. nIf the fetus is alive – cesarean section immediately, if die – fetal destroying noperation.
OBSTETRICS VERSIONS
Operations for correction of abnormal lie or npresentation of fetus definite as obstetrics versions. There are two types of nobstetrics versions: external and internal podalic version.
Indications nfor obstetrics versions: fetal malpresentations (breech, transverse and oblique nlie).
Contraindications. Complicated pregnancy, multifetal pregnancy, ncongenital uterine anomalies, placenta previa, feto-pelvic disproportion.
Conditions: for the external version – 32-36 weeks, nintact membranes, normal movement of the fetus in the uterus, satisfactory nfetal and mother condition; for the internal podalic version – ncervix must be fully dilated, intact or just rupture membranes, normal movement nof the fetus in the uterus, satisfactory mother condition, absence of nfetopelvic disproportion.
The internal podalic version consists of such moments:
1. Inserting a hand into uterine cavity.
2. Finding a foot.
3. Grasping one foot.
4. Drawing foot through the cervix while exerting npressure transabdominally in the opposite direction on the upper portion of the nbody.
The version is finished when fossa poplitea of the ngrasping foot in presented in the pudendal cleft.
DEFLEXED nPRESENTATIONS
There are 3 types of fetal head extension – sinciput vertex, brow and face npresentation. n
Etiology. The causes of deflexed npresentation are manifold, there are the factors that favors extension or nprevents flexion the head. Extended position of the head occur more frequently nwhen the pelvis is contracted or fetus is very large. In multiparous women the npendulous abdomen predisposes to deflexed presentation. In exceptional ninstances, marked tumors of the fetal neck or coils of cord about the neck may ncause extension. Anencephalic fetus present by the brow or face because of nfaulty development of the cranium.
Sinciput nvertex presentatio- is a I ndegree of head extension.
Diagnosis. The diagnosis of the deflexed vertex presentation bases on the nresults of the vaginal palpation: the sagittal suture, the large and the small nfontanels on the same level. The fetal head presents with a fronto-occipital ndiameter, a leader point is the large fontanel.
The cardinal nmovements of labor in deflexed vertex presentation are:
· ndeflexion;
· ninternal rotation;
· nflexion;
· nextension;
· ninternal rotation of the fetal body and external rotation of nthe fetal head.
1. Deflexion. The sagittal suture is nin the transverse or oblique size of the pelvic inlet. The head fixes to the ninlet and some deflexed. The large fontanel becomes the leader point.
2. Internal nrotation. This movement is a manner that the occiput gradually moves nfrom its original position posteriorly towards the sacrum os. The rotation is ncomplete when the head reaches the pelvic floor; the sagittal suture is in the nanteroposterior diameter.
3. Flexioof the head. Flexion begins when the head fixes by its root of the nose n(the first fixing point) to the inferior margin of symphysis pubis. The flexiofinishes when the occiput comes to the tip of sacrum and the second fixing npoint forms.
4. Extension of the head. After internal rotatioand flexion the fetal head closely touched with the area of the occiput to the ntip of the sacrum. The head extends and deliveries.
5. Internal nrotation of the fetal trunk and external rotation of the fetal head. This moment realizes as in anterior nocciput presentation.
The brow npresentation is a II degree of extension.
With the brow npresentation, that portion of the fetal head between the orbital ridge and the nfrontal suture presents at the pelvic inlet. The fetal head thus occupies a nposition midway between full flexion (ociput) and full extension (mentum or nface). Except when the fetal head is very small or the pelvis is unusually nlarge, engagement of the fetal head and subsequent delivery cannot take nplace as long as the brow presentation persists.
Diagnosis. The diagnosis of the nbrow presentation bases on the results of the external obstetrics examinatioand vaginal palpation. The brow presentation may be recognized by abdominal npalpation when both the occiput and chin can be easily palpated. The reliable ninformation can be felt by the vaginal examination: the frontal suture, the nlarge fontanel, orbital ridges, eyes, and root of the nose. The nose and mouth ncaot be palpable.
The fetal head presents with a mento-occipital ndiameter, a leader point is the middle of the frontal suture.
The delivery nat term in brow presentation is impossible. The preterm delivery, when the nfetus is small is possible and the characteristically deforms of the head noccurred. The caput succedaneum is over the fore head and may be so extensive nthat identification of the brow by palpation is impossible.
If the labor nis possible the cardinal movements in brow presentation nare:
1. Deflexion. The frontal suture is ithe transverse size of the pelvic inlet. The head fixes to the inlet and ndeflexed. The middle of the frontal suture becomes the leading point.
2. Internal nrotation.
3. Flexioof the head.
4. Extension of the head.
5. Internal nrotation of the fetal trunk and external rotation of the fetal head.
Face npresentation – head is hyperextended so that the occiput is in contact with the fetal nback and the chin (mentum) is presenting part.
Diagnosis. By nabdominal palpation the occiput, the chin and the angle between the fetal back nand the occiput can be easily palpated. The fetal heart sound are the loudest nfrom the side of the fetal thorax. On vaginal palpation, the distinctive nfeatures of the face presentation are the mouth, nose, the malar bones, and the norbital ridges.
Face npresentation is rarely observed above the pelvic inlet. The brow generally npresents and is converted to a face presentation after further extension of the nhead during descent through the pelvis.
The ncardinal movements of labor in face posterior presentation are:
1. Deflexion. The face linea is in the ntransverse size of the pelvic inlet. Descent is brought about by the same nfactors as vertex presentation. The head presented its vertical diameter. The nchin is the leading point.
2. Internal nrotation. The object of internal rotation of the face is to bring the nchin under the symphysis. Only in this way the neck subtend the posterior nsurface of the symphysis pubis. If the chin rotates directly posteriorly, the nbirth of the head is impossible.
3. Extension of the head. After the rotation and ndescent, the chin and mouth appear at the vulva, the undersurface of the chipresses against the symphysis, and the head is delivered by flexion. The nose, neyes, brow and occiput then appeared in succession over the anterior margin of nthe perineum.
4. Internal nrotation of the fetal trunk and external rotation of the fetal head. The shoulders are born as nin vertex presentations.
In face nanterior presentation- cesarean section is performed because of risk of ncephalopelvic disproportion.
Synclitism nand asynclitism. Synclitism is a position when the sagittal suture is ithe transverse pelvic diameter. The sagittal suture lies exactly midway betweethe symphysis and promontory.
If the nsagittal suture approaches the sacral promontory, more of the anterior parietal nbone presents itself to the examining fingers and the condition is called anterior nasynclitism. If the sagittal suture lies close to the symphysis more of nthe posterior parietal bone presents and the condition is called posterior nasynclitism.
