Mechanism and Management of Labour Flashcards Preview

Scientific Basis of Midwifery > Mechanism and Management of Labour > Flashcards

Flashcards in Mechanism and Management of Labour Deck (39)
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1
Q

How many weeks gestation is considered ‘term’?

A

37-42 weeks

2
Q

What happens to the cervix as labour begins?

A
  • Cervical ripening occurs at the end of pregnancy

- At term, cervix undergoes hypertrophy and an inflammatory-type reaction occurs

3
Q

What are Braxton-Hicks?

A

Contractions that increase in frequency and amplitude as labour begins

4
Q

Describe the first stage of labour

A
  • 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)
5
Q

How long is the 1st stage of labour?

A
Nulliparous = avg. 8h, max. 18h
Multiparous = avg. 5h, max. 12h
6
Q

Describe the second stage of labour

A
  • 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
7
Q

How long is the 2nd stage of labour

A
Nulliparous = avg. 3h
Multiparous = avg. 2h
8
Q

Describe the third stage of labour

A
  • Delivery to expulsion of placenta
  • Common complication = haemorrhage
  • Clamping cord should be delayed for over 1 min to increase neonatal iron stores
9
Q

What are the signs of placental separation?

A
  • Gush of vaginal blood
  • Lengthening of umbilical cord
  • Rise in uterine fundus
10
Q

Describe the management of the 3rd stage of labour

A
  • Routine use of uterotonic drug (Syntocinon or Syntometrine)
  • Controlled cord traction
  • Clamping and cutting of cord
11
Q

How long is the 3rd stage of labour?

A

Active management = 30 mins

Physiological management = 90 mins

12
Q

What are the normal stages of labour?

A
  1. Descent
  2. Flexion
  3. Internal rotation of head
  4. Extension
  5. Restitution
  6. Internal rotation of shoulders
  7. Lateral flexion
13
Q

What is extension?

A

Foetal head escapes under the symphysis pubis and crowning occurs

14
Q

What is restitution?

A

Head is delivered and rotates slightly externally

15
Q

How do the shoulders rotate internally?

A

Anterior shoulder rotates forwards to sit under symphysis pubis in AP position

16
Q

What is lateral flexion?

A

Anterior shoulder slips under pubic arch and over perineum - remainder of body born by lateral flexion through 3 pelvic planes (curve of carus)

17
Q

What symptoms suggest that the woman should go in for an evaluation of labour?

A
  • Possible rupture of membranes
  • Regular contractions
  • Vaginal bleeding
  • Severe back, abdominal or pelvic pains
18
Q

What observations should be taken during labour?

A
  • 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
19
Q

When should foetal heart auscultation occur?

A

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

20
Q

When should continuous electrical foetal monitoring be performed?

A
  • Meconium stained liquor
  • Abnormal foetal HR
  • Maternal pyrexia (increased temp/ fever)
  • Fresh vaginal bleeding
  • Oxytocin
  • Mother requests it
21
Q

What is considered an abnormal foetal heart rate?

A

> 160

<110

22
Q

How should the midwife assess progress of labour?

A
  • Strength and frequency of contractions

- VE every 4 hours

23
Q

What are the 3 factors that influence progress?

A
  1. Power
  2. Passenger
  3. Passages
24
Q

How does power influence progress of labour?

A

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
25
Q

How do contractions affect heart rate?

A

More than 5 contractions in 10 mins = contractions compromise uteroplacental circulation = not enough oxygen = hyperstimulation = tachysystole

26
Q

How does the passenger influence progress of labour?

A
  • Progress influenced by foetal size and position
  • Abdominal palpation required to access descent of presenting part
  • Cervical assessment provides information about station of presenting part in relation to ischial spines
27
Q

How do the passages influence progress of labour?

A
  • Abnormality may cause delay
  • Cephalopelvic disproportion = occurs with normal proportions of pelvis vs. macrosomic foetal head
  • Rigid perineum may cause delay (may require episiotomy)
28
Q

What are the NICE guidelines for delayed 1st stage of labour?

A
  • Cervical dilation <2cm in 4 hours for 1st labours
  • Cervical dilation <2cm in 4 hours or slowing progress for 2nd and subsequent labours
  • Descent and rotation of head
  • Changes in strength, duration and frequency of uterine contractions
29
Q

Describe the interventions that should occur in delay of labour in 1st stage

A
  • Support, hydration and effective pain relief
  • Amniotomy if membranes are intact 2 hrs after VE
  • Oxytocin if delay confirmed 2 hours after VE in nulliparoud
  • Multiparous = full examination by obstetrician if delay 2 hours after VE
  • If oxytocin required, transfer women to high risk care and cEFM
30
Q

Describe the interventions that should occur in delay of labour in 2nd stage

A
  • Intervene after 1 hour delay (4h nulli, 3h multi)
  • Amniotomy if membranes are intact
  • Consider further pain relief
  • Examination by obstetrician required if delay is diagnosed
  • Review every 15-30 mins
  • Consider instrumental delivery/ CS
  • NICE do not recommend use of oxytocin at this stage
31
Q

Describe the interventions that should occur in delay of labour in 3rd stage

A
  • Delay = >30 mins (active) or >90 mins (physiological)
  • If physiological delay, commence active management
  • If placenta not delivered for further 30 mins, or earlier if there’s bleeding, make assessment and give appropriate analgesia to remove placenta manually
32
Q

How is 1 to 1 support beneficial?

A
  • Reduction in pain relief requirements
  • Less operative intervention
  • Improved birth experience
33
Q

What is a TENS machine and when should it be used?

A
  • Trans-cutaneous nerve stimulation

- Latent phase only

34
Q

What temperature should a water birth be?

A

37 degrees C

35
Q

What are the 2 main types of opiates used in labour?

A
  • Pethidine

- Diamorphine

36
Q

What effect do opiates/ epidural analgesia have on labour?

A
  • Latent phase may be slowed by them

- They have little/ no effect in active phase

37
Q

What negative effects can opiates have on the body?

A
  • Drowsiness, nausea and vomiting
  • Short-term respiratory depression
  • BF interference
38
Q

What negative effects can an epidural have?

A
  • Slowed 2nd stage

- Increased incidence of operative delivery

39
Q

What is the preferred posture in labour

A
  • Provide ample space
  • Birth pools, mats, cushions, rocking chair, gym balls
  • Discourage supine/ semi-supine position in 2nd stage; associated with delayed instrumental delivery
  • Squatting increases pelvic diameter by 8mm
  • Changing positioning may help labour progress