1.3 - Occiptio-posterior Fetal Position In Labour - exam

Question 1

Identify and explain the physiology and characteristics of occipito-posterior position of the fetus

Answer 1

Occiput transverse (OT) position is a type of fetal cephalic malposition in which the sagittal suture and fontanels align 0 to <15 degrees from the transverse plane of the maternal pelvis

Question 2

Describe the midwifery management strategies to support a spontaneous vaginal birth when the fetus adopts an occipito-posterior position

Answer 2

• encourage the woman to adopt positions utilising thigh flexion which increases the pelvic diameter
• promotes foetal rotation to the OA position
• the larger diamond shaped fontanelle is anterior in the pelvis the fetus is in the OP position

Question 3

Using these resources explain the physiology of occipito-posterior (OP) position of the fetus

Answer 3

• Common malposition of the fetus
• LOP ROP and direct OP
• fetal head is not fully flexed
• occiput diamerer is 11.5 cm
• pelvis shape
• painful labour
• back ache
• pressure on the maternal spine
• pain gateway

Question 4

Describe the common characteristics which are displayed in an OP labour

Answer 4

• deflection of the fetal head
• +/- fetal head swelling
• maternal cervix oedema
• assisted delivery
• maternal back pain
• longer labour

Question 5

Describe the midwifery management and potential maternal positions which can optomise a vaginal birth

Answer 5

• on all fours
• hip flexion to increase pelvic diameter
• doesn’t
• lying on fetal spine side
• upward forward position
• tens, WFI,

Question 6

Describe key elements of assisted birth including indication, method and the role of the midwife in supporting the woman

Answer 6

• inefficient uterine action resulting in a long labour
• contracts varies in strength and
• uneven pressure on the pelvic floor resulting in inadequate uterine activity
• early rupture of membrane
• earlier urge to push
• focused breathing
• on all floors
• ambulate
• midwifery support
  
  • hydrated and nutrition well tolerated
  • rest position
  • maternal exhaustion
  • empty bladder frequently

Question 7

Describe the indication and method for assisted birth

Answer 7

• deflexed head
• unable to descend
• would more likely lead to forceps or c-section due to maternal and fetal exhaustion

Question 8

Describe the midwifery role during assisted birth

Answer 8

• pelvic shape
  *

Question 9

Why is it important to lower the caesarean section rate in Australia and globally?

Question 10

What is the evidence around increased intervention during labour and birth?

Answer 10

• evidences indicates that there is an increased intervention during labour & birth
• even for low risk women
• start with an intervention usually ends in a intervention
  *

Question 11

Mechanism of long internal rotation of a right OP Position

Answer 11

• Lie - longitudinal
• Attitude - of head is deflexed
• Presentation -vertex
• Position - is right occipitoposterior
• Denomination - is occiput
• Presenting part - is the middle to anterior are of the left paretal bone

Question 12

The movements - long anterior rotation

Answer 12

Descent and flexion:

• there is continued descent with flexion during the first stage of labour.
• The presenting diameter of occipitofrontal (11.5) is converted to suboccipitofrontal (10cm)

Internal rotation of the head:

• The occiput reaches the pelvic floor first and rotates forwards along the right side of the pelvis 3/8 th of a circle to lie under the symphysis pubis
• the anteroposterior diameter of the head now lies in the anteroposterior diameter of the pelvis
• the shoulders follow and rotate 2/8 ths of a circle
• the occiput escapes from beneath the subpubic arch

Restitution:

• restitution is a movement made by the head after it have been deliver which brings it into correct alignment with the shoulders.
• this will be 1/8th of a circle towards the side of the occiput.

Internal rotation of the shoulders:

• the anterior shoulder is the first to reach the pelvic floor and rotates towards to lie under the symphysis pubis.
• this movement is accompanied by external rotation of the head 1/8th of a circle more in the direction of resitution
• the occiput now lies laterally turned towards the woman’s thigh

Lateral flexion:

• the anterior shoulder is usually born first and slips under the pubic arch and the posterior should passes over the perineum
• the remainder of the body is born by lateral flexion
• (most common outcome for 65% births)

Question 13

• Identify the difference in fetal attitude with an OP fetal position

Question 14

Mechanism of labour

Answer 14

• As with all mechanisms of labour
• three pertinent points to remember
• descent and flexion will occur throughout
• the part that meets the resistance of the pelvic floor first
• that part will rotate around to the anterior
• will rest under the symphysis pubis
• what has rested under the symphysis pubis must be born firST

Question 15

ROP

Answer 15

• ROP
• Shoulder in the LOP
• occiput will be at the right sacroiliac joint
• the fetal
• ROP position of the pelvis
• Fetal head being in the right oblique of the pelvis
• fetal shoulders in the left oblique of the pelvis
• Occiput pointing to the right sacroiliac joint
• now as labor progresses descent and flexion occur throughout
• the Occiput reaches the resistance of the pelvic floor because complete flexion has occurred
• commence the long anterior rotation to the occipito anterior position
• roatation around to the AP diameter of the pelvis this is done in 2 steps the baby undertakes a short rotation of 45 degrees into the transverse diameter of the pelvis
• at this point the fetal shoulders are still in the left oblique diameter of the pelvis the second part is when the fetal head then undertakes a 90 degree turn from the transverse diameter of the pelvis into the AP diameter the pelvis and at the same time there is internal rotation of the shoulder’s from the left oblique into the right oblique diameter of the pelvis there is a twist in the baby’s neck and then the mechanism
• Labor then follows as normal crowning will occur because the Oxford is the path that is under the symphysis pubis so crowning occurs once the Oxford has escaped or been birthed from under the symphysis pubis and then extension occurs sweeping the since put face and chin over the perineum and the head is born then restitution occurs moves back to 45 degrees back into the left oblique diameter of the pelvis the next step in the mechanism is the internal rotation of the shoulder’s where the shoulders now move from the right oblique into the anterior posterior diameter and this is manifest by the head going into the transverse diameter then the body is born by lateral flexion the anterior shoulder sweeps under the symphysis pubis then the posterior and the body is born by lateral flexion and placed onto the mother’s abdomen this is an alternative outcome to a uh for a baby that presents in the occipital posterior position

Question 16

• Describe the 2 potential mechanisms of an OP position which result in a vaginal birth

Answer 16

This is an alternative outcome to a OP for a baby that presents in the occipital posterior position whereby the flexion is not complete and thus in support becomes a leading part and it’s a sensor put that meets the resistance of the pelvic floor and rotates and comes to rest under the symphysis pubis which means the occiput is now in the posterior aspect of the pelvis at this point the fetal shoulders are still in the left oblique again with the steps of the mechanism whatever is out of the symphysis pubis must be born first so The sinicupt support is born up to the glabella or the eyebrows and once that has escaped murder The Simpsons pubis then gentle flection is applied to the sensor put to allow the escape of the occiput over the perineum once that has occurred the fetal head is grasped and then by extension the face and chin sweep our from under the symphysis pubis and the head is born restitution takes the form of the baby rotating back 45 degrees to the right to its original position of right occipito posterior the shoulders are still in the left oblique then internal rotation of the shoulders occurs and this is manifest by the external rotation of the head into the transverse the anterior shoulder is now under the symphysis pubis and he’s born the posterior shoulder sweeps the perineum and then the baby’s body is born and swept over onto the mothers abdomen

Question 17

• Describe the third potential outcome which does not result in a vaginal birth

Answer 17

Outcome to a baby who presents in the occipital posterior position in this outcome the baby’s head does not completely flex so flexion is incomplete the Occiput does meet the resistance of the pelvic floor and does commence the short anterior rotation into the transverse diameter of the pelvis because flexion is complete it is the occipital frontal diameter of 11.5 centimeters that meets the diameter between the issue spines of 11 and therefore further rotation cannot continue because the diameters are differ at this point the fetal head may become caught on the issue or spines and intervention may be required either in the form of manual rotation and instrumental birthday the forceps or vacuum or in some cases it may require an emergency cesarean section um if this happens um they if a baby is born by forceps it’s manually rotated around to the anterior and the mechanisms of birth follower as normal