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
During labour there are many changes to the cervix
- Cervical dilatation
- Cervical effacement - thinning of the cervix
- Cervical consistency - softening of the cervix
- Cervical position - becomes more anterior
What causes the cervical softening? - an aicd causes the eventual breakdown among collagen fibre bridging
There is an increase in hyaluronic acid which will cause an increase among the molecules among collagen fibres - this will cause an increase in the breakdown of collagen fibre bridging - causes softening of the cervix and cervical effacement
What are the contractions known as that can start at six weeks but aren’t usually felt till second or third trimester?
These are Braxton Hick’s contractions
What is thought to be the purpose of Braxton-Hick’s contractions?
Braxton-Hick’s contractiosn - thought to be the tightening of the uterine muscles to prep the body for childbirth - no cervical dilation
How do true labour contractions feel?
How does the abdomen feel during a true labour contraction?
How long do they last when they first begin?
True labour contractions feel like a wave - pain starts low and rises until it peaks and then ebbs away
Abdomen feels hard during a contracion and at first contractions last between 5-10 minutes (usually)
Braxton-Hicks contractions are sometimes called “false labour” because they give the woman a false sensation that she is having real contractions. Although they can thin the cervix, the opening of the uterus, they won’t ultimately lead to delivery.
Are braxton hicks contractions painful?
Do the contractions increase in intensiy or frequency like true labour contractions
Braxton-Hick’s contractions are not meant to be painful
The contractions do not increase in intensity or frequency
True labour is when the contractions are evenly spaced (for example, five minutes apart), and the time between them gets shorter and shorter (three minutes apart, then two minutes, then one).
As the time between contractions decreases, what happens to the length of time of the contraction?
WHat is the main hormone that stimulates contractions? Where is it produced from?
As the time between contractions are decreasing, the length of time of the contraction is also increasing
The main hormone that stimulates contractions is oxyctoin released from the posterior pituitary gland
Real contractions will also get more intense and painful over time.
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
Contractions start infrequently and may be noticed at 10-15 minute intervals
The always get longer and more intense feeling
There is accompanied cervical changes , softening, effacement and dilatation
What is cervical softening known as for the bishop’s score?
WHat is cervical effacement?
Cervical softening is the cervical consistency change (firm, middle, soft)
Cervical effacement is the cervix becoming thinner as the second stage of labour nears
Braxton Hicks Contractions vs Labour contractions
- Frequent and painful?
- Resolve with a change in position?
- Begin at 6 weeks?
- Abdomen is hard during contraction?
- Frequent and painful- True Labour contraction
- Resolve with a change in position - Braxton-Hicks Contractions
- Begin at 6 weeks - Braxton-Hicks Contractions
- Abdomen is hard during contraction - True Labour Contractions
Uterine muscle: smooth muscle (myocyte) in connective tissue (collagen and elastin)
Where is the uterus muscle density highest?
What are the main types of collagen fibres in the cervix?
Uterine muscle density is highest at the fundus
Main collagen fibres in the cervix are types 1,2,3,4
Contraction and retraction leads to shortening of the muscle fibres
Propels baby down birth canal and exerts pressure on the cervix
What is the pacemaker region of contraction said to be?
This is said to be the tubal ostia - abdominal ostia - contractions waves start low in intensity and spread in a downwards direction
The intensity of the contraction is measured by putting your hand on the abdomen and seeing how long it remains hard for
Contractions begin lasting for 10-15 seocnds, what is the max length of the contraction?
How many contractions in 10 minutes is seen as normal?
Contraction duration(intensity) should increase to a max of 45 seconds
Normal for up to 3-4 contractions in 10 minutes
Progressively more intense, frequent and longer lasting
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)
There is a relationship between the clinical state of the cervix and onset of labour.
The cervix can be characterized by evaluating five parameters.
What are these five parameters? (same parameters as in the bishop’s scoring system)
We need to assess all factors during a vaginal examination in labour
- Cervical Effacement
- Cervical Dilatation
- Cervical Consistency (firmness)
- Cervical Position
- Level of presenting part - station
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
How often should vaginal examinations be carried out in normal labour?
How often should dilation of cervix be assessed during labour?
Vaginal examinations should be carried out 4 hourly
Dilation of the cervix should be assessed hourly - normal for a 1-2cm icnrease in dilation every hour
There are different types of pelvis
Which is the pelvis most suitable female pelvic shape?
Gynaecoid pelvis - the most suitable female pelvis shape
What is the normal lie of the pelvis?
Longitudinal lie is the normal lie of the pelvis - lei relates the longitudinal axis of the foetus to the longitudinal axis of the mother
What position should the head engage in? (the head is engaged when only 2/5ths can be felt above the pubic symphysis)
What is the normal type of presentation?
What is the normal presenting part?
What position is the foetal head when exiting the pelvic?
Normal type of presentation - cephalic
Normal presenting part - vertex
Normal position the head engages in is occipito-transverse
Foetal head exits the pelvis in an occupitoanterior position
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
The baby engages in the occipito-transverse psoition, what happens inside the pelvis before the baby exits in the occipitoanterior ?
What happens after exit from the pelvis?
Baby internally rotates and flexes its chin and then exits the pelvus
The babies head then goes into extension and then delivery to the anterior shoulder
Birth crowning, which is when your baby’s head starts to emerge bit by bit during each contraction, occurs during the second stage of labor.
What may be carried out to prevent an anal sphincter tear in mothers when crowning begins?
A mediolateral episiotomy
The third stage of labour is delivery of the palcenta
For this to occur the placenta must separate from the uterus
What are the three signs that the placenta has separated from the uterus known as?
The three signs:
- Uterus contracts, hardens and rises
- There is a rush of blood - various amounts
- The umbilical cord also lengthens permanently
When is the placenta usually used after delivery?
The placenta should be delivered within 5-10 minutes
Up to 30 minutes is considered normal
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)
The placenta separates from the uterus through the spongy layer of the decidua basalis
What are the three signs that placental separation has occured again?
Uterus contracts, hardens and rises
The umbilical cord lengthens permanently
There is a rush of blood - due to retroplacental haemorrhage - this helps mechanically shear the placenta from the spongy decidua basalis
What drugs can be given for active management of the third stage of preganancy again?
Syntometrine or oxytocin 10 units
Active management decreases the risk of post partum haemorrhage
What is it known as when the placenta does not separate from the uterine lining?
This is known as placenta accreta
There are different analgesic options for a pregnant mother
- Paracetamol/ Co-codamol
- TENS
- Entonox
- Diamorphine
- Epidural
- Remifentanyl
- Combined spinal/epidural
What is entonox?
Entoxnox is medical nitrous oxide and oxygen mixture - commonly known as laughing gas
What is a normal blood loss after pregnancy?
What volume is abnormal?
What volume is of significant worry?
Normal blood loss volume is less than 500mls
Abnormal is greater than 500mls
Significant worry is greater than 1500mls
Any blood loss prior to delivery apart from “show” is abnormal and requires referral to consultant unit
After a woman gives birth, womb muscles contract, why should this help?
What happens if the womb muscles do not contract hard enough?
The womb muscles contract clamping down on blood vessels which helps to reduce bleeding during delivery of the placenta
If the muscles do not contract well enough, this can lead to increased bleeding during placental delivery - PPH
How does haemostasis work after pregnancy?
The uterine muscle strangualtes the blood vessels
Also thrombosis of the blood vessels ends as pregnancy is a hyper-coaguable state
Puerperium is Period of repair and recovery
Return of tissues to non-pregnant state in 6 weeks
What is the Vaginal discharge containing blood, mucus and endometrial castings known as?
This is the lochia - also known as the postpartum period
How long does the lochia blood stained discharge last for?
The lochia usually lasts for 10-14 days after pregnancy but can last longer
The bleeding starts off as bright red and then over the next few days it changes colour and becomes browner as your womb heals and returns to its pre-pregnancy size.
The bleeding should have stopped altogether by the time your baby is about six weeks old.
What colour is the blood known as:
- Rubra?
- Serosa?
- Alba?
Rubra -this is the bright red fresh blood in first few days
Serosa - the brownish red blood
Alba - the old yellow blood
Involution is the process by which the uterus is transformed from pregnant to non-pregnant state. It is a physiological process occurring after parturition; the hypertrophy of the uterus has to be undone since it does not need to house the fetus anymore.
What does the weight of the uterus during pregnancy reduce from to?
The weight of the uterus reduces from 1000grams to 50-100grams
The fundal height of the pelvis returns from umbilicus to pelvis in what time period during uterine involution?
The fundal height of the uterus should be from umbilicus to pelvis within 2 weeks during uterine involution
Physiological diuresis commences 2-3 days postnatally
Lactation is initiated by placental expulsion
What hormones decrease at delivery?
What hormone produces beast milk?
What hormone cause smooth muscle contraction to eject milk from the nipple?
Oestrogen and progesterone decrease at delivery
Meaning prolactin can cause the production of milk
Oxytocin causes smooth muslce contraction to eject milk from the nipple
