Normal Labour And Its Management Flashcards
Death from maternal causes is related to which preventable things and where is this most prevalent
Severe bleeding, infection and pre-eclampsia
Highest lifetime chance of dying from maternal causes is in the middle of Africa. The African continent in general has higher lifetime than the continent of Europe
Lifetime risk is greater than that of the world
How many intrapartum stillbirths per year and what % of these are preventable
1.2 million
80% of these are preventable
Risk for an African woman is 50x higher
Of the above amount 55% of the still births are from rural families in Africa and South Asia
What substances are responsible for the retention and release in the process of labour
Retention:
- progesterone ( strengthens the sphincter of internal os
cervix, adrenaline,
relaxins = produced by ovaries and placenta
and CRH = prohibits prostaglandins production
Release:
- oestrogen
- oxytocin
- ADH = acts alongside oxytocin
- cortisol = decreases progesterone secretion. Secreted by foetal adrenal cortex
- prostaglandins = increases muscle contractility and smooth muscle relaxation
- uterine distension
-CRH = increases myometrium contractility during labour
The process of labour is dependent on which 3 mechanisms
Passage (dilated enough and the type of pelvis )
Power ( frequency of contractions and pushing from the mother) also supplemented by the tone of the abdominal muscles and voluntary contraction of the abdominal wall muscles
Passenger ( what position the baby is in)
What are the 4 pelvic types
- gynecoid (pelvis is wide and round) (most common and accommodates childbirth the most)
- android (heart shaped)
- anthropoid (more oval shaped and narrower)
- platypelloid ( pelvis is flat and very wide but is shallow) (least common)
What are the 4 important properties of the uterus
Tone = resting tone in between contractions helps downward movement of foetus
Contractility = uncoordinated contractions means labour can fail to progress
Fundal dominance = wave of contraction is most dominant in fundus and moves down
Rhythmicity = usually at a rate of 4 per 10 minutes
From what week does resting tone of the uterus increase and what does it result in
From week 35
Results in Braxton hicks contractions which are usually painless and infrequent
As term approaches there will be an increase in the number of contractions and frequency especially in pre- labour
What enables uterus to return to its pre-pregnant size
Contractions will persist after birth
What is the smallest diameter of the foetal skull and how does it optimise vaginal delivery
Sub-occipital bregmatic
When the foetus has a flexed head against the chest and posterior fontanelle is visible first
What is excessive moulding
Excessive overlap of the skull bones under compression due to cephalopelvic disproportion
What occurs during the latent phase of labour
Onset of interactions at regular intervals at 3-4cm dilation with the cervix fully effaced
What changes happen to the cervix in the latent phase
Over a few days the cervix changes from a hard tubular structure to a soft membranous layer.
What is cervical effacement
Head will press against the cervix and this causes release of prostaglandins which act to soften and shorten the cervix
What characterises the first stage of labour
Regular contractions progressing from 3-4cm to fully dilated
What characterises the second stage of labour
Full dilatation until the delivery of the baby
Passive phase = where foetus descends as a result of passive contractions
Active phase = descent due to mother pushing
Cardinal movements of labour
Engagement = baby’s head engages in transverse position in mothers pelvis
Descent
Flexion
Internal rotation
Extension
External rotation = baby’s head returns to OT position
Expulsion
Characteristics of third stage of labour
From the delivery of the baby to the delivery of the placenta
What is critical about the third stage of labour
Once the placenta is delivered there are open vascular beds that can bleed torrentially
It is vital that muscle contracts around blood vessels to provide haemostasis. Without this there will be postpartum haemorrhage
= synthetic oxytocin and controlled cord contraction is offered to speed up the third stage of labour
Roles of mid wives in labour
Evaluation of maternal and foetal condition
Evaluation of the birth plan
Partogram
1-1 support
Regular bladder emptying especially when epidural is given
What is used to document the progress of labour
Partogram
On x axis is hours after admission and y axis is cm of dilation
Straight line across is the standard curve and if at any point the patients curve crosses below the standard intervention should be delivered
What can hinder dilation and how is it remedied
Pain can hinder natural dilation of cervix and this can be remedied by administering synthetic prostaglandins
Duration of labour ( monoparous vs multiparous )
Different types of analgesia used in labour
Simple oral analgesics = paracetamol
TENS = transcutaneous nerve stimulation (latent phase mostly)
Entonox = mixture of NO and oxygen
Systemic opiates = pethidine, meptid, morphine or diamorphine
Epidural
How is foetal wellbeing monitored
Craniotopography
What does craniotopography assess
- uterine muscle activity = if contractions occur too frequently it can cause hypoxia is foetus
- detect foetal heart rate
Normal is 100-160bpm
Can become tachycardic or bradycardic
Role of the obstetrician
Failure to progress to first stage - which P is it?
Failure to progress to second stage
Foetal compromise - sepsis, hypoxia
Maternal compromise - sepsis or haemorrhage
Delayed 3rd stage = to reduce risk of postpartum haemorrhage
What is the leading case of maternal mortality after birth
First = suicide (post-natal blues experienced by 50-80% of women following pregnancy)
2nd = post partum haemorrhage
Commonest direct cause is thromboembolism
Commonest indirect cause is cardiac disease
