Intrapartum care & labour Flashcards
What is this defining: the process of uterine contractions and cervical dilation that enables the uterus to deliver the viable foetus (>24wks), placenta and membranes?
Labour!
When is labour diagnosed?
When there are
- regular and
- increasing painful contractions
- at least every 5 mins
that brings about progressive cervical effacement & dilation
when a blood stained mucus plug is passed from the cervix this is called loss of “show”.
does this indicate labour?
no.
labour = regular and increasing painful contractions (5mins), loss of show doesnt define lanbour
NOR DOES SPONTANEOUS RUPTURE OF MEMBRANES (SROM)
although these events may happen around the same time…
When does “normal labour” occur?
at term which = 37 - 42 weeks
should have a spontaneous, smooth progression of contraction and dilation, cephalic presentation, spontaneous vaginal delivery with minimal complications for mother/baby
What are the main problems if “normal” labour doesn’t occur? (~37-42wks etc)
if pre term: baby can have Acute respiratory distress sydnrome (ARDS) and complications of prematurity
if after term: the placenta begins to die
What stage of labour does latent and established phase come under?
the first stage
What stage of labour does active and passive come under?
the 2nd stage
What is the 3rd stage of labour?
delivery of the placenta
What is the first stage of labour - the latent phase?
- painful, often irregular contractions
- the cervix is effacing (becoming shorter and softer)
- & dilation –> 3/4cm
What is the first stage of labour - established phase?
regular contractions with dilatation from 3–>10cm @1cm/hr
What is the second stage of labour - passive?
complete cervical dilation e.g. to 10 cm but no pushing
What is the second stage of labour - active?
maternal pushing using the abdominal muscles and valsalva until the baby is born!
(valsalva = a woman is instructed to take a deep breath at the beginning of the contraction, to hold her breath and push as long and hard as she can in synchrony with her contractions.)
What do prostaglandins and oxytocin do in the uterus during labour?
they increase intracellular free calcium ions e.g. help with contraction
What organ in labour does this description refer to?
- must soften, shorten, thin out (effacement) and dilate
the cervix
What organ during labour does this refer to?
- must change to an active state of regular, strong, frequent contractions
- followed by a resting phase in order to maintain placental blood flow & adequate perfusion of the foetus
The uterus!
What changes happen to the upper segment of the uterus during labour?
there is progressive uterine SMC retraction (shortening) here
–> makes the thicker, actively contracting “upper segment”
What changes happen to the lower segment of the uterus in labour?
- the lower segment = thinner and more stretched
- until eventually the cervix is “taken up” e.g. effaced into the lower segment of the uterus
- so forming a continum with the lower uterine segment
How do you describe the frequency of contractions?
- describe the frequency per 10 min interval e.g. 2 in 10
- this increases to 4-5 in 10 mins during advanced labour
- duration varies from 30-60s
[NB: contractions are involuntary]
What changes do prostaglandins, interleukins and dermatan sulphate replacement cause in the cervix during labour?
They all cause cervical softening (“ripening”) so that contractions can cause effacement/dilatation
PG’s
- increase proteolytic activity
- decrease collagen & elastin
Interleukins:
- proinflammatory change with neutrophil invasion
hydrophilic hyaluronic acid replaceing dermatan sulphate:
- increase water content of cervix
What is the name of the graphic representation of the progress of labour?
partograms
What does the alert line on a partogram show?
it is drawn at 1cm/hr from the start of active phase (e.g. where maternal pushing using abdo musc. and valsalva until the baby is born)
– would show where the labour is starting to not progress
what does the action line on a partogram show?
it is parallell to the alert line but 2-3cm to the right
if labour progresses to the right of this line = slow labour and may need intervention
what intervention can be given if labour progresses to the right of the action line on a partogram?
- rupure membranes (help descend, PG release);
- artificial oxytocin
Apart from the alert and action line what else do partograms show?
Maternal parameters:
- pulse, BP, temp, urine output
Maternal labour:
- Rate of cervical dilation
- Descent of head
- Contraction frequency & duration
Foetal:
- heart rate
- Caput & moulding of head
What observations should be done on mum and baby during labour?
Mum -
- BP, temp
- contractions,
- bladder emptying (full bladder can hinder uterine contraction and if empty = more space for baby to go through)
- vaginal examination,
Baby -
- foetal heart rate & intermittent auscultation (IA)
- every 15 mins in 1st stage,
- 5 mins in 2nd stage (>10cm)
What is a cardiotocograph (CTG)?
- it uses a pressure transducer (tocodynamoter) positioned on the abdomen at the fundus of the uterus
- or foetal scalp electrode
- to produce a foetal ECG
- it assesses the frequency of contraction and their intensity/amplitude of uterine contractions (30-60mmHG)
What do these factors to mum and baby represent?
Mum:
- Previous C section
- Labour: IOL , Oxytocin augmentation, Epidural anaesthesia
- Medical: Maternal cardiac problems, PET or HTN, Diabetes of any type
- Obs: Prolonged rupture of membranes >24hrs; Post-maturity (>42wks) / Prematurity <37wks; APH or intrapartum haemorrhage; Pyrexia; Abnormal umbilical artery Dopplers
Baby:
- Small for gestational age
- Oligohydramnios
- Abnormal lie
- Multiple pregnancy
- Meconium-stained liquor
- Abnormality heard on intermittent auscultation
the indications for electronic foetal monitoring - cardiotocograph (CTG)
What is DR C BRAVADO to do with interpreting CTG’s?
- DR - define risk - why is woman having CTG?
- C - contractions - how many per 10mins
- BRA - baseline rate - normal foetal HR = 100-160bpm
- V - variability (of HR) - reduced if there is foetal hypoxia, malformation, magnesium & prematurity OR sleeping
- A - an up spike of >15bpm for >15s = reassuring, occurs when foetus is moving
- D - decelerations = down spike of >15bmp for >15s - can be normal with contractions
- O - overall: normal vs non-reassuring vs abnormal