Normal Labour And Puerperium

Question 1

What is labour?

Answer 1

a physiological process during which the foetus, membranes, umbilical cord and placenta are expelled from the uterus

Question 2

What factors are responsible for initiation of labour?

Answer 2

• Change in estrogen/progesterone ratio
• Fetal adrenals and pituitary hormones may control timing of the onset of labour
• Myometrial stretch increases excitability of myometrial fibres
• Mechanical stretch of cervix and fetal of membranes
• Ferguson’s reflex

Question 3

What is Fergusons reflex?

Answer 3

a neuroendocrine reflex in which the foetal distension of the cervix stimulates a series of neuroendocrine responses, leading to oxytocin production

Question 4

What hormonal factors influence onset of labour?

Answer 4

• Progesterone keeps the uterus settled - prevents formation of gap junctions, hinders the contractibility of myocytes
• Oestrogen makes the uterus contract and promotes prostaglandin production
• Oxytocin initiates and sustains contraction, acts on decidual tissue to promote prostaglandin release
  
  • Oxytocin is synthesized directly in decidual and extraembryonic fetal tissues, and in the placenta

Question 5

Other causes of labour onset?

Answer 5

• Pulmonary surfactant secreted into amniotic fluid has been reported to stimulate prostaglandin synthesis
• Increase in production of foetal cortisol stimulates an increase in maternal estriol
• Increase in myometrial oxytocin receptors and their activation results in phospholipase C activity and subsequent increase in cytosolitic calcium and uterine contractility

Question 6

What cervical changes occur during labour?

Answer 6

• Cervical softening - increase in hyaluronic acid will decrease bridging among collagen fibres, decreasing firmness of the cervix
• Cervical ripening - changes include a decrease in collagen fibre alignment and strength, decrease in tensile strenght of the cervical matrix, and an increase in cervical decorin

Question 7

What are the stages of labour?

Answer 7

First stage (consists of latent and active phases)
Second stage
Third stage

Question 8

Latent phase of first stage of labour?

Answer 8

• mild irregular uterine contractions, cervix shortens and softens, duration variable
  
  • May last a few days

Question 9

Active phase of first stage of labour?

Answer 9

• 4cms onwards to full dilatation
  
  • Slow decent of the presenting part
  • Contractions progressviely become more rhythmic and stronger
  • Normal progress is assessed at 1-2cms per hour

Question 10

Second stage of labour?

Answer 10

• Starts with complete dilatation of the cervix fully dilated (10cms) to delivery of the baby
• In nulliparous (never given birth) women it is considered prolonged if it exceeds 3 hours if there is regional analgesia, or 2 hours without.
• In multiparous women it is considered prolonged if it exceeds 2 hours with regional analgesia or 1 hour without.
• In low risk care vaginal examinations are not always carried out to assess time of full dilatation

Question 11

Third stage of labour?

Answer 11

• Delivery of the baby to expulsion of the placenta and fetal membranes, takes ~10 mins.
• After 1 hour, preparation made for surgical removal either by regional analgesia or under GA
• Expectant management - spontaneous delivery of the placenta.
• Active management - use of oxytocic drugs and controlled cord traction is preferred for lowering risk of post partum haemorrhage.

Question 12

What influences contractions in labour

Answer 12

• Uterine muscle - smooth muscle in connective tissue, density highest at the fundus
• Pacemaker - region of tubal ostia, wave spreads in a downward direction
• Synchronisation of contraction waves from both ostia
• Polarity: upper segment contracts and retracts, lower segment and cervic stretch, dilate and relax
• Normal contractions have a fundal dominance with a regular pattern and adequate ‘resting tone’

Question 13

What is tubal Ostia?

Answer 13

a translucent membrane lying at the junction between the intramural segment of the fallopian tube and the uterine cavity.

Question 14

What is puerperium?

Answer 14

• Period of repair and recovery ~ 6 weeks involving return of tissues to non-pregnant state
• Bloodstained discharge lasts 10-14 days following birth

Question 15

Clinical features of labour?

Answer 15

Brixton hicks contractions
True labour contractions
Signs of the third stage

Question 16

Another name for braxton hicks contractions?

Answer 16

“False labour”

Question 17

Features of braxton hick contraction?

Answer 17

• ‘False labour’
• Tightening of the uterine muscles, thought to aid the body to prepare for birth
• Can start 6 weeks into pregnancy but more usually felt in the third trimester
• Irregular, do not increase in frequency or intensity
• Resolve with ambulation or change in activity
• Relatively painless

Question 18

Features of true labour contractions?

Answer 18

• Happen under the influence of the release of oxytocin, which stimulates the uterus to contract
• True labour is when the timing of the contractions become evently spaced, and the time between them gets shorter and shorter
• Real contractions will get more intense and painful over time

Question 19

Features of third stage?

Answer 19

• Expulsion of placenta usually 5-10 minutes after delivery, considered normal up to 30 minutes
• Uterus contracts, hardens and rises
• Umbilical cord lengthens permanently
• Frequently a gush of blood variable in amount
• Placenta and membranes appear at introitus

Question 20

Investigations used for labour?

Answer 20

Bishops score
Partogram

Question 21

What is bishop score used for?

Answer 21

used to determine whether if it is safe to induce labour

Question 22

Components of bishop score?

Answer 22

Position, consistency, effacement, dilation, station in pelvis

Question 23

What is a Partogram?

Answer 23

a graphic record of key data (maternal and fetal) contained onto one sheet, used to assess progress of labour i.e. cervical dilatation, fetal heart rate

Question 24

Non-pharmacological analgesic methods for labour?

Answer 24

• Exercise/movement
• Heat e.g. warm bath, heat pack
• TENs stimulation
• Acupuncture
• Hypnosis
• Massage

Question 25

Another name for “gas and air”

Answer 25

Nitrous oxide or entonox

Question 26

3 types of analgesic for labour?

Answer 26

Simple analgesics
Opiate analgesics
Epidural analgesics

Question 27

Example of simple analgesia?

Answer 27

Paracetamol

Question 28

Opiate analgesic examples?

Answer 28

• Oral codeine phosphate
• IV/IM Diamorphine

Question 29

Features of epidural analgesic?

Answer 29

• Does not impair uterine activity
• Associated with a longer second stage of labour
• Does not increase chance of caesarean birth but there is a slightly increased chance of an operative birth
• Complications: hypotension, dural puncture, headache, high block, atonic bladder

Question 30

What is pudendal nerve block?

Answer 30

An injection of medication close to your pudendal nerve in your pelvic region to provide temporary pain relief. Some injections provide prolonged pain relief.

Question 31

What areas does the pudendal nerve innervate?

Answer 31

Your pudendal nerve runs from the back of your pelvis to all the muscles and skin in your genital area, including the anus, vagina and vulva, and penis.

It’s a part of your peripheral nervous system.

Question 32

Pudendal nerve block relieves contraction pain. true/false?

Answer 32

False

Used to relieve pain during the second (pushing) stage of labour. A pudendal block can be given through the vaginal wall and into the pudendal nerve in the pelvis.

Whilst the perineal region is numbed, this does not relieve the pain of contractions.

Question 33

What is the importance of skin to skin contact for mother and baby?

Answer 33

Early placing of the naked baby on the mother’s chest (SSC) helps keep babies warm and calm and considered to improve other aspects of a baby’s transition to life outsidethe womb

Question 34

What is involved in the active management of third stage of labour?

Answer 34

Includes prophylactic administration of syntometerine (ergometrine maleate and oxytocin) or oxytocin

Question 35

What factors affect the passage of the baby?

Answer 35

Types of female pelvis
Bony outlet of pelvis
Cervical assessment
Foetal position

Question 36

What are the 4 types of female pelvis?

Answer 36

Gynaecoid (most suitable pelvic shape)
Platypelloid
Android
Anthropoid

Question 37

Why is gynaecoid pelvis the most suitable pelvic shape?

Answer 37

The wide, open shape give the baby plenty of room during delivery.

This is suitable compared to the android pelvis since the narrower shape of the android pelvis can make labor difficult because the baby might move more slowly through the birth canal. Some women may require C-section

Question 38

What is the consequence of immediate clamping of the umbilical cord?

Answer 38

Can reduce the red blood cell the infant receives at birth by more than 50%.

This can cause potential long and short-term neonatal problems.

Question 39

What are the 7 cardinal movements of labour?

Answer 39

Engagement
Descent
Flexion
Internal Rotation
Extension
Restitution and external rotation
Expulsion