Week 4 - B - Normal Labour And Peuperium - Bishops Scale, Labour Stages, Placental Separation Flashcards
What is the physiological process during which the fetus, membranes, umbilical cord and placenta are expelled from the uterus. known as?
This is labour
What is the puerperium?
This is the 6weeks after childbirth during which the mother’s organs to their original non-pregnant condition
During Labour there is an interplay of three key factors. These three fators can affect delivery of the baby and are also known as as the three Ps
WHat are they?
- Power - uterine contractions
- Passage - maternal pelvis
- Passenger - size of the foetus
What hormone, present to maintain the lining of the endometrium, prevents the uterus from contracting?
What is the other hormone whose levels rise with the first hormone throughout pregnancy and then drop once delivery of the baby has happened? It stimulates uterine contraction
Progesterone keeps the uterus settled
Oestrogen makes the uterus contract
What hormones does oestrogen stimualte the production of to stimulate uterine contractions?
WHat is the main hormone that is present for initiating and stimulating uterine contractions?
Oestorgen stimulates the production of prostoglandins which increase uterine contractions
Oxytocin is the main hormone of uteirne contractions
Oxytocin acts on decidual tissue to promote prostaglandin release
What is the decidual tissue?
The decidual tissue is the endometrium
What is the name given to the neuroendocrine reflex comprising the self-sustaining cycle of uterine contractions initiated by pressure at the cervix or vaginal walls?
What causes the pressure at the cervix or vaginal walls?
When there is pressure, what hormone does this cause an increase in the release of?
This is the Ferguson Reflex
Increasing pressure at the cervix or vaginal walls due to the baby being delivered causes an increase in the release of oxytocin from the posterior pituitary gland
Pulmonary surfactant secreted into amniotic fluid has been reported to stimulate prostaglandin synthesis (remember prostoglandin synthesis stimulates uterine contractions)
What is the role of the pulmonary surfactant in the lungs?
The role of the pulmonary surfactant in the lungs is to reduce the alveolar surface tension - keeps the alveoli from collapsing
WHat is the Law of LaPlace? Used to calculate the pressure acting inwards on the alveoli
P = 2T / r
Pressure is directly proportional to the surface tension of the alveoli
Pressure is inversely proportional to the radius of the alveoli (smaller radius, larger pressure)
What is the scoring system used by midwifes and obstetricians to indicate whether it is safe to induce pregnancy?
This is the Bishop’s scoring system
What are the five elements of Bishop’s scoring system?
- Cervical dilatation
- Position of cervix
- Consistency of cervix
- Effacement
- Station
What does a score of 5 or less on the Bishops score indicate?
What does a score of 9 or more indicate?
A score of 5 or less suggests that labour is unlikely to start without induction.
A score of 9 or more indicates that labour will most likely commence spontaneously.
Bishop score remains the best and simplest method available to determine if it is safe to induce labour.
Even though a score of 5 or less indicates the use for induction, will it e successful?
Low scores make the likelihood of successful induction unlikely
A score of 0,1,2 or 3 can be given as Bishop’s scoring for each of the sections - apart from cervical consistency and cervical positon (can only be given 0,1or2)
- What is meant by cervical consistency?
- What is meant by cervical position?
- What is meant by cervical effacement?
- What is meant by cervical dilatation?
- Cervical consistency - how firm or soft the cervix is (softer is easier for dilatation of the cervix)
- Cervical position - the position of the cervix changes with menstrual cycles and also tends to become more anterior (nearer the opening of the vagina) as labour becomes closer.
- Cervical effacement - Effacement translates to how ‘thin’ the cervix is. - the cervix will become very thin as labour approaches
- Cervical dilataation - how dilated the cervix is
Why is it that a more anterior sitting cervix is given a greater score than posterior on Bishop’s score?
What is meant by foetal station?
As the cervix becomes more anterior as labour becomes closer - it is given a bigger score as this means it reduces the likelihood of requiring labour induction
Foetal station - the station of the foetus in relevance to the distance of the foetal head from the ischail spines of the pelvis
Run through the different aspects of Bishop’s score again?
Which aspects count for 3 points max and which for 2 points max?
2 points max -
- Cervical position
- Cervical consistency (firm, medium, soft)
3 points max
- Cervical Dilatation
- Foetal station
- Cervical effacement (how thin is the cervix)
There are 3 stages of labour
What is a summary of each stage?
First stage
- Cervix dilates up to 10cm (fully dilated)
Second stage
- Cervix is fully dilated - delivery of the foetus
Third stage
- Expulsion of the membranes and placenta
The first stage of labour is divided into latent and active phase
What is the difference in dilatation for these phases?
- Latent phase - cervix is up to 3-4cms dilated
- Active phase - cervix is 4 to 10cm dilated (Active phase 4cms onwards to full dilatation)
Latent phase of labour is the dilatation of the cervix up to 3-4 cms – can last a couple days
Occassionaly there are latent phases which they actually induce as it has last 4/5 days
Describe the type of uterine contractions that take place here?
Mild irregular uterine contractions take place here
The cervix also shortens (thins- cervical effacement) and softens in this phace (cervical consistency)
Active phase 4cms onwards to full dilatation,
Slow decent of the presenting part
Describe the uterine contractions in this phase?
What is normal progress of dilatation in the active phase of the first stage of labour?
The uterine contractions in the active phase become more rhythmic (regular) and stronger
1-2cms increased dilation per hour in this phase (0.5cm/hour is satisfactory)
When does the second stage of labour begin?
Why is the baby said to be able to be delivered when the cervix is dilated to 10 cm?
The second stage of labour begins when the cervix is fully dilated - 10cm until delivery of the baby
The baby passes through the cervix (this is where the pelvic inlet will be i believe) in a transverse direction and therefore occipitoanterior diameter of foetus will need to match with diameter of cervix - as diameter of cervix is 10cm and OA diameter is 9.5cm - the head can pass through
What is considered prolonged second stage of labour in nullparous and multiparous women? Both using and not using analgesia
WHat does nullaprous mean?
In nulliparous women, second stage is considered prolonged if it exceeds 3 hours if there is regional analgesia, or 2 hours without
In Multiparous women, the second stage considered prolonged if it exceeds 2 hours with regional analgesia or 1 hour without
A nullparous women is one who has never had a child
Normal labour occurs after 37 weeks gestation and results in spontaneous vaginal delivery of the baby how long after the onset of regular spontaneous contractions?
What stage of labour do regular spontaneous contractions begin?
Normal labour occurs after 37 weeks gestation and results in spontaneous vaginal delivery of the baby within 24 hours after the onset of regular spontaneous contractions
It is the active (established) phase of the first stage of labour when contractions become regular and spontaneous
The third stage of labour is the expulsion of the placenta and membranes
How long should this take?
Up to how long is considered normal?
When is preparation for removal under general anaesthetic made?
This stage should take around 10 minutes
Up to 30 minutes is considered normal
Preparation for removal under general anaesthetic is made after 1 hour
Expectant management- spontaneous delivery of the placenta
Active management: use of oxytocic drugs and controlled cord traction
Why is active management for the third stage of pregnancy sometimes preferred?
It is preferred as it lowers the risk of post-partum haemorrhage
How much blood loss is post partum haemorrhage defined as?
Blood loss greater than 500mls in the first 24 hours after delivery
What does active management of the third stage of labour include?
- Includes prophylactic administration of Syntometerine or Oxytocin 10 units
- Cord clamping and cutting
- Controlled cord traction
- Bladder emptying
Contractions tighten the top part of your uterus pushing the baby downward into the birth canal in preparation for delivery.
What is the positive feedback reflex of the uterine contractions known as?
What does contractions also promote for the cervix?
This is known as the Ferguson Reflex
Contractions also promote thinning of the cervix
Engagement of the foetal head is measured by measuring the abdominal fifths of the foetus
Ie how many fingers width above the pubic symphysis can you feel of thd foetal head
When is the head said to be engaged?
Foetal head is said to be engaged when only 2fingers are palpable (2/5ths)
What are the four fontanelles?
What are the sutures of the feotal skull?
What is the anterior fontanelle known as once its closed? WHen does it close?
Anterior fontaelle, posterior, sphenoid (anterolateral), mastoid (posterolateral)
The frontal suture, saggital, coronal suture, lamboidal suture, squamous suture
The anterior fontanell closes by 18 months and then is known as bregma
There is differnent timing for the rupture of the membranes
What is it known as when the foetus is born completely inside the amniotic sac?
This is an en-caul birth
When the placenta separates in the third stage of layer, what layer of the uterus is it separating from?
The palcenta separates from the decidua basalis (spongy endometrial layer)
