Labour (stages; CTGs) Flashcards
What is the definition of labour? [1]
Onset of regular, painful contractions AND
Cervical changes (dilatation, effacement, softening)
The length of the first stage of labour varies widely:
First labour: an average of around [] hours may be expected, rarely would it last longer than 18 hours.
Subsequent labour: may last around [] hours on average and rarely longer than 12 hours.
The length of the first stage of labour varies widely:
First labour: an average of around 8 hours may be expected, rarely would it last longer than 18 hours.
Subsequent labour: may last around 5 hours on average and rarely longer than 12 hours.
The length of the second stage varies widely:
Nulliparous (no previous births): normally will last less than [] hours
Multiparous (more than one previous birth): normally will last less than [] hours
Length
The length of the second stage varies widely:
Nulliparous (no previous births): normally will last less than 3 hours
Multiparous (more than one previous birth): normally will last less than 2 hours
What are the three stages of labour? [3]
- The first stage is from the onset of labour (true contractions) until 10cm cervical dilatation.
- The second stage is from 10cm cervical dilatation to delivery of the baby.
- The third stage is from delivery of the baby to delivery of the placenta.
What are prostaglandins key in preganancy? [1]
What is the clinical significance of them? [1]
Prostaglandins act like local hormones, triggering specific effects in local tissues:
- They play a crucial role in menstruation and labour by stimulating contraction of the uterine muscles.
- They also have a role in the ripening of the cervix before delivery.
One key prostaglandin to be aware of is prostaglandin E2. Pessaries containing prostaglandin E2 (dinoprostone) can be used to induce labour.
What are Braxton-Hicks contractions? [1]
Braxton-Hicks contractions are occasional irregular contractions of the uterus.
These are NOT true contractions, and they do not indicate the onset of labour.
They do not progress or become regular. Staying hydrated and relaxing can help reduce Braxton-Hicks contractions
What are the signs of labour? [4]
Abdominal pains – regular, initial frequency 2-3 in 10 minutes
Passage of show – mucous plug, brownish or blood stained (not always)
Water leak (often) – but typically waters should break in labour
Others (nausea, vomiting, general malaise…)
Describe what is meant by cervical efficacement [2]
Cervix gets thinner and dilates and opens up
Describe in detail the first stage of labour
Include the different phases of the first stage of labour [3]
First stage: from the onset of labour until the cervix is fully dilated to 10cm
It involves cervical dilation (opening up) and effacement (getting thinner from front to back)
The “show” refers to the mucus plug in the cervix, that prevents bacteria from entering the uterus during pregnancy, falling out and creating space for the baby to pass through.
Phases of the first stage:
Latent phase:
- From 0 to 3cm dilation of the cervix.
- This progresses at around 0.5cm per hour. There are irregular contractions.
Active phase::
- From 3cm to 7cm dilation of the cervix.
- This progresses at around 1cm per hour, and there are regular contractions.
Transition phase:
- From 7cm to 10cm dilation of the cervix.
- This progresses at around 1cm per hour, and there are strong and regular contractions.
NICE guidelines on intrapartum care (2017) refer to the latent first stage and established first stage.
What is the difference between them? [1]
The latent first stage is when there are both:
* Painful contractions
* Changes to the cervix, with effacement and dilation up to 4cm
The established first stage of labour is when there are both:
* Regular, painful contractions
* Dilatation of the cervix from 4cm onwards
Describe the second stage of labour [+]
The second stage of labour lasts from 10cm dilatation of the cervix to delivery of the baby.
The success of the second stage depends on “the three Ps”: power, passenger and passage.
1. Power:
- the strength of the uterine contractions.
2. Passenger: the four descriptive qualities of the fetus:
- Size: particularly the size of the head as this is the largest part.
- Attitude: the posture of the fetus. For example, how the back is rounded and how the head and limbs are flexed.
- Lie: the position of the fetus in relation to the mother’s body: Longitudinal lie – the fetus is straight up and down; Transverse lie – the fetus is straight side to side; Oblique lie– the fetus is at an angle.
- Presentation: the part of the fetus closest to the cervix: Cephalic (head first); Shoulder presentation (shoulder first); Breech presentation (legs first)
3. Passage: the size and shape of the passageway, mainly the pelvis.
What is descent with regards to labour? [1]
Obstetricians describe the position of the baby’s head in relation to the mother’s ischial spines during the descent phase. Descent is measured in centimetres, from:
* -5: when the baby is high up at around the pelvic inlet
* 0: when the head is at the ischial spines (this is when the head is “engaged”)
* +5: when the fetal head has descended further out
E.g could be +2
For how long would you wait before considering ventouse or forceps? [1]
Wait 1hr
Describe what happens in the third stage of labour
The third stage of labour is from the completed birth of the baby to the delivery of the placenta.
- Physiological management is where the placenta is delivered by maternal effort without medications or cord traction.
- Active management of the third stage is where the midwife or doctor assist in delivery of the placenta
What would indicate active management of the placenta? [2]
What drug is used for active management? [1]
What feeling is associated with active management? [1]
Haemorrhage, or more than a 60-minute delay in delivery of the placenta, should prompt active management.
Active management involves giving a dose of intramuscular oxytocin to help the uterus contract and expel the placenta.
Active management can be associated with nausea and vomiting.
Describe the monitoring given in labour for the fetus [1] and mother [5]
Fetus:
* FHR monitored every 15min (or continuously via CTG)
Maternal:
* Maternal pulse rate assessed every 60min
* Maternal BP and temp should be checked every 4 hours
* VE should be offered every 4 hours to check progression of labour
* Maternal urine should be checked for ketones and protein every 4 hours
* Contractions assessed every 30min
What is the name for this device? [1]
Pinard stethoscope - for fetal HR
A partogram is used to monitor the active phase of the first stage of labour.
Describe what you would measure on the partogram and what it would indicate if these were atypical [+]
A tool for monitoring maternal and foetal wellbeing during the active phase of labour, and a decision-making aid when abnormalities are detected
Fetal HR
- Normal is 110-160
- Maternal pulse, BP, temperature (raised if chorioamnionitis, UTI, group B streptococcal infection) and urianalysis (protein = pre-eclampsia/liquor contamination; glucose = diabetes; ketones = starvation; blood = UTI/obstructed labour)
Contractions:
- Frequency per 10 mins: 2nd stage of labour aim is 1min contractions in 10 mins, 3-5 strong)
- Strength
- Regularity
Cervical dilatation:
- PV exam performed every 4hrs: aim is 1cm/hr primiparous, 2cm/hr multiparous
- Alert line: 1cm/2hrs if primiparous or 1cm/hr if multiparous
Head descent:
- PV exam every 4 hrs
- Assess: Fifths palpable per abdomen; station of presenting part (measured in relation to ischial spine); position (orientation of fetal head - feel for fontanelles/sutures); moulding (extent of overlapping fetal skull bones); caput: swelling of presenting part
Liquor:
- Noted every hour
- Assess if intact: clear (membrane rupture), bloody (placental abruption) or meconium present (fetal distress)
What can caused reduced variability in CTGs? [6]
Fetal sleeping: this should last no longer than 40 minutes (this is the most common cause)
Fetal acidosis (due to hypoxia): more likely if **late decelerations **are also present
Fetal tachycardia
Drugs: opiates, benzodiazepines, methyldopa and magnesium sulphate
Prematurity: variability is reduced at earlier gestation (< 28 weeks)
Congenital heart abnormalities
Describe the difference in causes between early, late and prolonged decelerations [3]
Early decelerations start when the uterine contraction begins and recover when uterine contraction stops
- This is due to increased fetal intracranial pressure causing increased vagal tone.
- It therefore quickly resolves once the uterine contraction ends and intracranial pressure reduces
- considered to be physiological and not pathological.
Late decelerations
- begin at the peak of the uterine contraction and recover after the contraction ends
- This type of deceleration indicates there is insufficient blood flow to the uterus and placenta. As a result, blood flow to the fetus is significantly reduced causing fetal hypoxia and acidosis.
Prolonged deceleration:
* A prolonged deceleration is defined as a deceleration that lasts more than 2 minutes:
* If it lasts between 2-3 minutes it is classed as non-reassuring.
If it lasts longer than 3 minutes it is immediately classed as abnormal.
The accelerations before and after a variable deceleration are known as the [] of deceleration. What do they indicate? [1]
The accelerations before and after a variable deceleration are known as the shoulders of deceleration
- Their presence indicates the fetus is not yet hypoxic and is adapting to the reduced blood flow.
- Variable decelerations without the shoulders are more worrying, as it suggests the fetus is becoming hypoxic.
What does a sinusoidal CTG patten indicate? [3]
A sinusoidal pattern usually indicates one or more of the following:
* Severe fetal hypoxia
* Severe fetal anaemia
* Fetal/maternal haemorrhage
What are the 4 Ps that are the main components of labour process? [4]
Facotors that influence each other during childbirth
Pysche
Power
Passage
Passenger
What is the normal cephalic presentation for a fetus? [1]
In normal (flexed) presentation the presenting diameter is suboccipito-bregmatic, measuring on average 9.5 cm.
FYI
Describe the different positions of the baby’s head during labour (and which ones are problematic) [4]
Occipito-anterior (OA):
- optimal position
- baby is head down with his or her face looking at spine
occipito-posterior (OP):
- baby is head down, facing naval
Occiput Transverse (OT) - R or L
- This is when the baby is lying at a right angle across the parent’s abdomen.
Breech
- Breech is when the baby is lying bottom down in the womb.
How can you determine which position the baby is during birth by feeling its head? [1]
Look at the fontanelles to determine position
- Posterior is triangular; hard;
- Anterior is a diamond; soft
- Therefore if the posterior further up: OA
Can feel the sagitalle suture (long one) - follow along until other suture. If theres 3 its posterior; if 4 and anterior is soft
What are the different mechanisms involved in labour? [7]
Engagement
Descent
Flexion
Internal rotation
Descent
Delivery by extension
External rotation (restitution)
