Normal labour

Question 1

How is labour defined?

Answer 1

1.The onset of increasingly regular and painful contractions
–Increasing to every 3-5 every 10 mins
2.Cervical dilatation

Question 2

What are the 3 stages of labour?

Answer 2

1st stage = from onset of labour to cervical dilatation to 10cm
2nd stage = delivery of baby (passive + active stages)
3rd stage = delivery of placenta

Question 3

What is the myometrium and what is its role?

Answer 3

-Muscular wall of the uterus, facilitating expansion during pregnancy and contractions during delivery
-IN PREGNANCY = remains quiescent to accommodate growth and development, stretching increases muscle contractibility
-IN LABOUR = strong contractions are synchronised by oestrogen signalling to cells to form a synchronised wave

Question 4

What changes does the cervix undergo during labour?

Answer 4

-Decrease in collagen content
-Increase in water content
-Enables to cervix to soften, efface and dilate

Question 5

What role do hormones play in labour?

Answer 5

-Increased OESTROGEN concentrations stimulates the release of PROSTAGLANDINS and formation of OXYTOCIN RECEPTORS
-Makes the myometrium more sensitive to oxytocin
-Both prostaglandins and oxytocin are strong myometrial stimulants and help with cervical ripening

Question 6

STAGE 2: How does the head change orientation during delivery?

Answer 6

1. Head enters pelvis / engages with the cervix in OCCIPITO-LATERAL POSITION
2. Head delivered in OCCIPITO-ANTERIOR position

Question 7

STAGE 2: How are the head and shoulders delivered?

Answer 7

1. Head is delivered in occipito-anterior position with complete neck extension
2. Restitution - head returns to occipto-lateral / transverse position
3. Anterior shoulder is delivered (head directed posteriorly)
4. Posterior shoulder is delivered (head directed anteriorly)

Question 8

STAGE 1: What do the different layers of muscles in the uterus do?

Answer 8

INNER HORIZONTAL = facilitate cervical dilatation and thinning by contracting upwards
OUTER VERTICAL = contract and shorten to expel the baby

Question 9

What are the 2 phases of the 1st stage of labour?

Answer 9

LATENT = painful contractions and some cervical changes including effacement and elation –>4cm
ACTIVE / ESTABLISHED = regular contractions and cervical dilatation from 4 –> 10cm

Question 10

What are the 2 phases of the 2nd stage of labour?

Answer 10

PASSIVE = full cervical dilatation prior to involuntary expulsive contractions
ACTIVE = expulsive contractions / active maternal effort

Question 11

How long should the 1st and 2nd stages of labour take?

Answer 11

1st stage = 5-12h (8-18 if nulliparous)
2nd stage = within 2 hours (3 if nulliparous)

Question 12

What is lochia?

Answer 12

-Vaginal discharge containing blood, mucus and uterine tissue
-Can continue for 6 weeks after childbirth

Question 13

How are women supported during labour?

Answer 13

-1:1 midwife care
-Maternal monitoring:
–Contractions (frequency, strength, length)
–Vaginal loss (heavy bleeding, meconium)
–Vital signs (infection, high BP, shock)
-Foetal monitoring:
–Low risk = doppler auscultation every 15 mins
–High risk = continuous CTG monitoring

Question 14

What is meconium and what is it a sign of?

Answer 14

-Effectively baby’s faeces
-Sign of foetal distress
-Classified as significant if it stains the liquor a dark green colour and is thick and tenacious
(-Non-signficant = thin, yellow)

Question 15

What can cause MSL during pregnancy or labour?

Answer 15

OBSTETRIC FACTORS = prolonged labour, post-term birth, IUGR, low weight babies, oligohydramnios
MEDICAL = anaemia, cholestasis
MATERNAL = drug use, high maternal age

Question 16

What outcomes are associated with MSL?

Answer 16

Associated with increased risk of:
-Respiratory distress
-Neonatal resuscitation
-Low APGAR scores
-Neonatal sepsis