Mechanisms Of Labour Flashcards
- How would you introduce self? Max 3
- Name/student midwife
- Confirm patient name
- Explain what will be doing today
- Gain consent
- Wash hands
WHO - 5 moments of hand hygiene
- 7 steps of hand washing
Use gel if hands visibly clean
- Discuss the approach you will be taking to deliver antenatal education? Max 3
Assets based approach
-find out what patient knows
- correct errors
- fill gaps
Demonstrate using doll and pelvis
- Definition of mechanisms of labour? 2 max
Widest diameter of foetus successfully negotiates widest part of pelvis - birth of baby.
- Describe basic anatomy of pelvis? 4 max
- 2 part - false and true pelvis
- False pelvis- brim and above (flared) - no interest to midwifery
- True pelvis is brim and below
- brim , cavity and outlet - vital to birth - It’s a bony girdle
- size and shape influences Labour (large baby causes probs)
- Pelvis brim- describe the anatomy and diameters. 8 landmarks
9 max
Brim- Sacrum and sacral promontory (vertebrae) at back - not circular (ovoid in shape)
Symphysis pubis at front
1. Sacral promontory
2. Sacral alla (wing)
3. Sacroiliac joint
4. Iliopectineal line -not visible
5. Iliopectineal eminence
6. Superior ramus
7. Upper border of pubic bone
8. Symphysis pubis
Diameters - anteroposterior 11cm
R and l oblique 12cm
Transverse 13cm
- Describe pelvis cavity and diameters. Max 7
- Inner part
- Almost circular
- Shallower at front - bordered by symphysis pubis
- Deeper at back - bordered by sacrum
- Finishes at coccyx
- Diameters all the same
A, o and t all 12cm - Sacrum forms curve of Carus and baby needs to negotiate this.
- Describe pelvis outlet and the diameters. 7 max
- Partially bound by ligaments
- Diamond shape
- Formed by coccyx/lower symphysis pubis and ligaments.
- Last part baby negotiates before birth
5 A 13 o 12 and t 11
Describe and demonstrate?
Descent. Max 11
- Engagement
- Prim from 36 wks - good tone
- Braxton hicks pushes through foetus and pushes baby down towards pelvic brim
- Parous - starts to happen around onset of Labour
- Foetus descends towards pelvis brim and when widest part of feral head had entered pelvis - engaged
- From antenatal exam fetal head is engaged from 3/5 or less in abdomen.-early in prim later in Parous.
Flexion. Max 5
- Happens due to good contractions and fetal descent
2.foetus is encouraged to descend - Contractions cause he uterus to push down on the foetus through occipital - fetal axis pressure
- When foetus pushed down it meets resistance of pelvis floor
- This causes foetus to tuck chin to chest-smaller diameters
- Foetus then negotiates it way through the pelvis brim
- Labour progresses
Increased Flexion makes presenting part smaller - easier to negotiate through pelvis.
Internal rotation. Max 6
- Flexion causing the foetus occipital to hit pelvic floor (gutter shape) causes resisitance high causes the foetus to internally rotate from Transverse to an anterior position (longest part)
- It’s happens during established labour and is usually completed by 2nd stage.
- Continued descent of foetus in a rocking motion causes visualisation of presenting part in the vuvla.
Crowning. Max 4
1.due to continued descent crowning occurs
2. Crowning- largest diameter of fetal head successfully negotiates through the narrowest part of maternal pelvis and passed through vulva.
3. When passed through vulva rocking motion stops and head stays there.- ring of fire occurs at this stage.
4. Midwife can help soothe this.
Extension. Max 6
- Head is born via extension
- Neck will pivot on sub-Punic arch
3.baby’s forehead sweeps perineum and head is born - Nose and chin born and then gradually whole head will be born
- Neck extends upwards against pubic arch- extension
Restitution. Max 4
When the head and neck are born they are twisted form body and therefore they need to realign- restitution
If any enters pelvis is a right occipital anterior position-head and neck need to realign.
This is done via internal rotation
Head and neck realign towards maternal right and turn about 1/8th of a circle.
External rotation of the head and internal rotation of shoulders. Max 9
After restitution next couple of strong contractions expect external rotation of the head and the internal rotation of the shoulders which happens at the same time.
Shoulders rotate to try get to the widest diameter of the pelvic outlet from T(11cm) to AP (13cm)
Head will turn round to face maternal thigh-similar to restitution- if started on right hand side then head willl turn towards maternal thigh in that direction and visa versa.
Lateral Flexion. Max 11
At this stage baby is nearly born- if midwife was sing hands on approach to assist with birth she would help the final stage which is lateral Flexion.
Baby follows curve of Carey’s the shape of the sacrum-midwife would use either a chin occipital grip or she would hold the side of the baby’s head
She would hold and pull downwards until the anterior shoulder pops out and visible at vuvla-slips under pubic arch
She will then use an upward motion-posterior shoulder slips against perinum
Midwife will then deliver the baby up onto abdomen.
Skin to skin-golden hour.
