Normal Labour

Question 1

when does labour typically occur?

Answer 1

between 37 and 42 weeks gestation

Question 2

what is labour?

Answer 2

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

Question 3

where does labour occur? and which is most common place for it to happen

Answer 3

• Consultant Led Unit
  
  • Midwife Led Unit
  • Homebirth

(96%- in hospital)

Question 4

what occurs to oestrogen: progesterone ratio in labour?

Answer 4

oestrogen increases: progesterone decreases

Question 5

role of progesterone in labour?

Answer 5

Progesterone settles the uterus and prevents it from contracting, prevents formation of gap junctions, hinders the contractibility of myocytes

during labour the oestrogen/progesterone levels change

-high levels of progesterone throughout pregnancy stops labour from being induced

Progesterone= Prevents

Question 6

role of oestrogen in labour?

Answer 6

makes the uterus contract and promotes prostaglandin production

Question 7

role of oxytocin in labour?

Answer 7

initiates and maintains uterine contraction

-Oxytocin is synthesized directly in decidual and extraembryonic fetal tissues, and in the placenta

Question 8

where is oxytocin synthesised?

Answer 8

Oxytocin is synthesized directly in decidual and extraembryonic fetal tissues, and in the placenta

Question 9

what initiates labour?

Answer 9

Change in oestrogen/progesterone ratio (progesterone decreases)
-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 10

what is Ferguson’s reflex?

Answer 10

Oxytocin stimulates contractions, this pushes baby’s head on cervix which triggers further oxytocin production

Question 11

role of pulmonary surfactant on initiation of labour?

Answer 11

Pulmonary surfactant secreted into amniotic fluid has been reported to stimulate prostaglandin synthesis

prostaglandins cause contractions

Question 12

role of foetal cortisol on initiation of labour?

Answer 12

increase of foetal cortisol, increases maternal oestrogen (increasing ostrogen: progesterone and inducing labour)

Question 13

what cervical changes are seen before inducing labour?

Answer 13

Cervical softening
Cervical reopening

Question 14

explain how cervical softening occurs?

Answer 14

increase in hyaluronic acid will decrease bridging among collagen fibres, decreasing firmness of the cervix

Question 15

explain how cervical reopening occurs?

Answer 15

changes include a decrease in collagen fibre alignment and strength, decrease in tensile strength of the cervical matrix, and an increase in cervical decorin

Excess of cervical decorin near term is capable if initiating a decorin-collagen interaction that leads to collagen fibril disruption and decreased cervical tensile strength

Question 16

What scoring system is used to decide if it’s safe to induce labour?

Answer 16

Bishops score

Question 17

how many stages of labour are there?

Answer 17

3

Question 18

what is the first stage of labour made up of?

Answer 18

Active and latent phase

Question 19

what occurs in the latent phase of labour and how long does it occur?

Answer 19

-mild irregular uterine contractions
-cervix shortens and softens
-cervix is dilated up to 3 or 4cms
-0.5cm dilatation per hour
-duration variable (may last a few days)

Question 20

how does the latent phase of a first time mother tend to differ?

Answer 20

it tends to be longer

Question 21

what is the size of the cervix at full dilatation?

Answer 21

10cms

Question 22

what occurs in the active phase of labour and how long does it occur?

Answer 22

-cervix dilated from 4cms to full dilatation (10cms)
-Slow decent of the presenting part
-Contractions progressively become more rhythmic and stronger
-1 to 2 cm dilatation per hour
-This is the stage most women need analgesia for

Question 23

what is the management for the active phase of labour?

Answer 23

-Normal progress is assed at 1-2cms per hour
-Analgesia, mobility and parity increase variability

Question 24

how dilated are women in 2nd stage of labour?

Answer 24

fully dilated (10cms) to delivery of baby

Question 25

what occurs in 2nd stage of labour?

Answer 25

delivery of baby

Question 26

when is 2nd stage of labour considered prolonged in nulliparous women?

Answer 26

Nulliparous women with analgesia >3 hours
Nulliparous women without analgesia >2 hours

Question 27

when is 2nd stage of labour considered prolonged in multiparous women?

Answer 27

Multiparous women with analgesia >2 hours
Multiparous women without analgesia >1 hour

Question 28

how long does stage 3 last on average?

Answer 28

about 10 mins

Question 29

what occurs in stage 3 of labour?

Answer 29

from delivery of baby to expulsion of placenta and fetal membranes

Question 30

when is third stage considered prolonged?

Answer 30

Passive management > 1 hour
Active management > 30 mins

Active management=
Give 10 IU of Oxytocin IM into thigh (just as anterior shoulder emerges)
IF no history of Pre-eclampsia = Ergometrine can be used (Oxytocin preferred)

Question 31

what is the active management for stage 3 of labour?

Answer 31

Give 10 IU of Oxytocin IM into thigh (just as anterior shoulder emerges)
IF no history of Pre-eclampsia = Ergometrine can be used (Oxytocin preferred)

use of oxytocic drugs and controlled cord traction is preferred for lowering risk of post partum haemorrhage

Question 32

what are Braxton hick contractions?

Answer 32

‘False labour’

Give women false sensation of real contractions

Question 33

when do braxton hicks contractions occur?

Answer 33

Can start 6 weeks into pregnancy
-usually felt in third trimester

Question 34

presentation of braxton hicks contractions?

Answer 34

-Irregular
-Do not increase in frequency or intensity
-Relatively painless
-Resolve with ambulation or change in activity

Question 35

what influences the 2nd stage of labour?

Answer 35

3 Ps
Power
Passage
Passanger

Question 36

what does power refer to in the 3 P’s?

Answer 36

the strength of the contractions

Question 37

what is a normal strength of contractions in the second stage?

Answer 37

3-4 in 10 mins

initially 10-15 seconds long but can last up to 45 seconds

they progressively become more frequent, longer lasting and more intense

Question 38

what does passage refer to in the 3 P’s?

Answer 38

this refers to the size and shape of the passageway, mainly pelvis

Question 39

what does the passanger refer to in the 3P’s?

Answer 39

the qualities of the fetus