Labour

Question 1

What are the roles of the different hormones involved in the initiation of labour?

Answer 1

Progesterone inhibits contractions
Oestrogen stimulates contractions
(more oestrogen : progesterone for labour)

Oxytocin initiates and sustains contractions and acts on decidual tissues to promote prostaglandin release

Question 2

What are the fetal contributions to the initiation of labour?

Answer 2

Fetal pulmonary surfactant - secreted into the amniotic fluid - stimulates prostaglandin synthesis

Fetal cortisol stimulates an increase in maternal oestrogen

Fetus causes stretch of the cervix (fergusons reflex)

Question 3

Describe the cervical changes which occur in normal labour?

Answer 3

Cervical softening and ripening

Question 4

What is Bishops score for?

Answer 4

To determine whether it is safe to induce labour

Score <5 = induction will be necessary, score >9= labour will likely occur spontaneously

Question 5

What are the 5 things involved in Bishops score?

Answer 5

Position

Consistency

Effacement

Dilatation

Station in the pelvis

Question 6

What happens in the first stage of labour?

Answer 6

Involves a latent and an active stage

latent stage: up to 4cm dilatation with mild irregular contractions

active stage: 4-10cm dilatation with slow descent of the presenting part, contractions are strong and rhythmic

Question 7

What happens in the second stage of labour?

Answer 7

From 10cm dilated to expulsion of the baby

Question 8

What happens in the third stage of labour?

Answer 8

Expulsion of the placenta and fatal membranes

Question 9

What analgesia options are available for labour?

Answer 9

Entonox

Paracetamol/ co-codamol

Diamorphine

Epidural

Remifentanyl

TENS machine

Question 10

What are the 7 cardinal movements in labour?

Answer 10

Engagement 
Descent 
Flexion 
Internal rotation 
Crowning and extension 
Restitution and external rotation 
Expulsion

Question 11

When is the fetus considered to be ‘engaged’ in labour?

Answer 11

When the widest brim of the fetal head has entered the brim of the pelvis

3/5ths = engaged (2/5ths can be palpated abdominally)

Question 12

What is crowning?

Answer 12

Appearance of the fatal head at the introitus

Question 13

Why is delayed cord clamping important?

Answer 13

Involves good blood flow to vital organs following delivery

Question 14

What volume is considered normal blood loss in labour?

Answer 14

<500mls

Question 15

What is the puerperium?

Answer 15

The period of 6 weeks after birth when there is repair and recovery of tissues and return to a non-pregnant state

Question 16

How long does blood stained discharge last following birth?

Answer 16

10-14 days

Question 17

When should labour be induced after rupture of the membranes?

Answer 17

Labour should usually be induced within 48 hours due to the risk of infections

Question 18

What is the normal frequency and duration of contractions in labour?

Answer 18

3-4 contractions in 10 minutes

Initially last 10 seconds and then increase up to about 45 seconds

Question 19

How is cord prolapse managed?

Answer 19

Urgent C-section

Question 20

What are some of the possible complications of using epidural anaesthesia for labour?

Answer 20

Hypotension

Dural puncture headache

Question 21

What are some of the possible signs of obstruction in labour?

Answer 21

Moulding

Caput

Anuria/ haematuria

Vulval oedema

Question 22

“DR BRAVADO” is a mnemonic used to help remember what to look for on a CTG. What does it stand for?

Answer 22

Dr = determine risk 
BRA = baseline heart rate 
V = variability
A = accelerations 
D = decelerations 
O = overall

Question 23

What is the normal baseline heart rate of a fetus?

Answer 23

110-150bpm

Question 24

Fatal blood sampling can be done during labour to determine hypoxia. What is the normal pH value?

Answer 24

Scalp pH >7.25 is normal

<7.2 requires immediate delivery

Question 25

What are the signs of placental separation?

Answer 25

Uterus contracts, hardens and rises

Increasing length of the umbilical cord is visible at the introitus

Gush of blood

Mother has a feeling of fullness

Question 26

What manoeuvre should be done if the babies shoulder gets stuck during delivery?

Answer 26

McRobert’s manoeuvre

Question 27

What are some of the causes of post partum haemorrhage?

Answer 27

Uterine atony (most common)

Retained products

Clotting factor deficiency

Perineal trauma

Question 28

What are some of the causes of antepartum haemorrhage?

Answer 28

Uterine rupture

Vasa praevia

Placental abruption

Placental accreata

Vasa praevia

Question 29

Which is the preferred drug for active managed of the 3rd stage of labour; syntometrine or syntocinon?

Answer 29

Syntometrine is preferred because it causes a sustained tonic contraction and reduces the risk of PPH

Question 30

Which cause of APH requires a laparotomy to remove the baby?

Answer 30

Uterine rupture

Question 31

What drug is used to prime the uterus for contractions after fetal demise?

Answer 31

Mifepristone (progesterone antagonist)

This is used in conjunction with misoprostol (synthetic prostaglandin)

Question 32

Why are mifepristone and misoprostol not commonly used to augment contractions in live pregnancies?

Answer 32

The strength and duration of the contractions they cause cannot be easily controlled and so they could cause contractions that are too frequent and thus hypoxia in a live fetus.