Mechanism and Management of Labour Flashcards
(39 cards)
How many weeks gestation is considered ‘term’?
37-42 weeks
What happens to the cervix as labour begins?
- Cervical ripening occurs at the end of pregnancy
- At term, cervix undergoes hypertrophy and an inflammatory-type reaction occurs
What are Braxton-Hicks?
Contractions that increase in frequency and amplitude as labour begins
Describe the first stage of labour
- 4cm to full dilation
- Latent Phase = painful contractions and cervical effacement
- Active Phase = regular painful contractions and cervical dilation
- Transitional Stage = towards end of 1st stage, change in behaviour (panic, fear, nausea, heavy show, shivering, urge to push)
How long is the 1st stage of labour?
Nulliparous = avg. 8h, max. 18h Multiparous = avg. 5h, max. 12h
Describe the second stage of labour
- Full dilation to delivery
- Passive Phase = begins at full dilation prior to/ in absence of involuntary expulsive effort
- Active Phase = begins when baby is visible and involves maternal effort, pH of foetal blood decreases which increases risk of foetal hypoxia
How long is the 2nd stage of labour
Nulliparous = avg. 3h Multiparous = avg. 2h
Describe the third stage of labour
- Delivery to expulsion of placenta
- Common complication = haemorrhage
- Clamping cord should be delayed for over 1 min to increase neonatal iron stores
What are the signs of placental separation?
- Gush of vaginal blood
- Lengthening of umbilical cord
- Rise in uterine fundus
Describe the management of the 3rd stage of labour
- Routine use of uterotonic drug (Syntocinon or Syntometrine)
- Controlled cord traction
- Clamping and cutting of cord
How long is the 3rd stage of labour?
Active management = 30 mins
Physiological management = 90 mins
What are the normal stages of labour?
- Descent
- Flexion
- Internal rotation of head
- Extension
- Restitution
- Internal rotation of shoulders
- Lateral flexion
What is extension?
Foetal head escapes under the symphysis pubis and crowning occurs
What is restitution?
Head is delivered and rotates slightly externally
How do the shoulders rotate internally?
Anterior shoulder rotates forwards to sit under symphysis pubis in AP position
What is lateral flexion?
Anterior shoulder slips under pubic arch and over perineum - remainder of body born by lateral flexion through 3 pelvic planes (curve of carus)
What symptoms suggest that the woman should go in for an evaluation of labour?
- Possible rupture of membranes
- Regular contractions
- Vaginal bleeding
- Severe back, abdominal or pelvic pains
What observations should be taken during labour?
- Temp = 4 hourly
- BP = 4 hourly
- Pulse = hourly
- Freq. of contractions = 1/2 hourly
- Document freq. of emptying bladder
- Urinalysis and abdominal palpation = initial assessment
When should foetal heart auscultation occur?
1st stage = intermittently after most recent contraction every 15 minutes for 60 seconds (palpate maternal pulse to differentiate HRs)
2nd Stage = intermittently after most recent contraction every 5 minutes for 60 seconds
When should continuous electrical foetal monitoring be performed?
- Meconium stained liquor
- Abnormal foetal HR
- Maternal pyrexia (increased temp/ fever)
- Fresh vaginal bleeding
- Oxytocin
- Mother requests it
What is considered an abnormal foetal heart rate?
> 160
<110
How should the midwife assess progress of labour?
- Strength and frequency of contractions
- VE every 4 hours
What are the 3 factors that influence progress?
- Power
- Passenger
- Passages
How does power influence progress of labour?
Uterine contractions
- Established labour = 4 in 10 mins
- Delivery can be achieved with less uterine activity - don’t measure progress by contractions alone
- Influenced by epidural anaesthesia, tocolytics and sedation
