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Flashcards in Normal labour** Deck (35)
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1
Q

during labour there is an interplay of which three factors

A

power - uterine contraction
passage - maternal pelvis
passenger - fetus

2
Q

progesterone does what

what happens to the levels in labour

A

keeps the uterus settles and prevents formation of gap junctions and hinders contractibility of myocytes

goes down

3
Q

oestrogen in labour

A

makes the uterus onctract

promotes prostaglandin production which produces more oestrogen

4
Q

what does oxytocin do in labour

where is it synthesised

what happens to the number of oxytocin receptors

A

initiates and sustains contractions
acts on decidual tissue to promote prostaglandin release

directly in decidual and extra embryonic metal tissues and in the placenta

increase in myometrial and decidual tissue near the end of the pregnancy

5
Q

how is labour initiated

A

change in oestrogen/progesterone ratio

fetal adrenals and pit hormones may control timing of onset of labour

myometrial stretch due to uterus getting bigger leads to excitability of myometrial fibres

mechanical stretch of cervix and stripping of metal membranes

fergusons reflex - increase oestrogen and increased prostaglandin release

6
Q

other causes that lead to labour

A

pulmonary surfactant secreted into amniotic fluid stimulates prostaglandin synthesis

increase in production metal cortisol stimulates an increase in maternal estriol

increase in my-metrical oxytocin receptors and their activation results in phospholipase C activity and subsequent increase in cytosolitic calcium and uterine contraction

7
Q

3 stages of labour consist of what

A

first - latent/active
second - cervix dilated to 10cm - delivery of baby
third stage - delivery of placenta and membranes

8
Q

latent stage

A

mild irregular uterine contractions, cervix shortens and softens, duration variable

9
Q

active phase

A

4cm on to full dilatation
slow descent of the presenting part
contractions progressively becomes more rhythmic and stronger

10
Q

second stage of the labour starts with what
how long does it take
what can happen in low risk px

A

starts with complete dilatation of the cervix (approx 10cm)

in nulliparous women considered prolonged if it exceeds 3 hours with regional analgesia or 2 hour without

in multiparous women - consider prolonged if it exceeds 2 hours with analgesia or 1 without

in low risk vaginal examinations are not always carried out to assess time for full dilatation

11
Q

what happens during the third stage of labour
time
management actions taken

A

delivery of the baby to expulsion of the placenta and fatal membranes

av duration 10 mins can be 3 min longer

spontaneous delivery of the placenta - be prepared
use of oxytocin drugs and controlled cord traction is preferred for lowering risk of post partum haemorrhage

12
Q

active management of third stage

A

syntometrine 1ml ampoule given
or
oxytocin 10 units

cord clamping and cutting
controlled cord traction
bladder emptying

13
Q

cervical softening

A

increase in hyaluronic acid gives increase in molecules among collagen fibres

decrease in bridging among collagen fibres gives decrease in firmness of cervix

14
Q

cervical ripening

A

decrease in collagen fibre alignment
decrease in collagen fibre strength
decrease in tensile strength of the cervical matrix
increase in cervical decorin

15
Q

braxton hicks contraction what

when do they start/are felt

A

tightening of the uterine muscles - thought to aid the body to help prepare for birth
can start 6 weeks into the pregnancy
not usually felt until second or third trimester

irregular, do not increase in frequency or intensity
resolve with ambulation or change in activity
relatively painless

16
Q

true labour contractions feelings

when

A

like a wave
pain starts low, rises until a peak and then ebbs away
if you touch the mothers abdomen during one it feels hard

start about 5 mins apart

17
Q

what causes true labour contractions

pain

A

oxytocin causes uterus to contract
evenly spaced
get more intense and painful over time
tighten the top part of the uterus pushing the baby down

18
Q

what do both kinds of contractions do to the cervix

A

promote thinning of the cervix

19
Q

where is the pacemaker and what direction does the wave spread
how do the waves synchronise
polarity
normal contractions have what

A

region of tubal ostia, downward direction

both ostia

upper segment contracts and retracts, lower segment and cervix stretch, dilate and relax

fundal dominance with a regular pattern and an adequate resting tone

20
Q

best type of pelvis t have

A

gynaecoid pelvis

21
Q

anthropoid pelvis

A

oval shaped inlet with large AP dm and smaller transverse dm

22
Q

android pelvis

who are more at risk of this type of pelvis

A

triangular or heart shaped inlet and is narrower from the front

african caribbean women

23
Q

what does liquor do

A

nurtures and protects fetus and facilities movement

24
Q

when does the membrane usually rupture

A

in the first stage

25
Q

abnormal position

A

breech, oblique, transverse

occipital posterior

26
Q

crowning of head - what happens

what may be required to prevent trauma to anal sphincters

A

labia are stretched to full capacity
largest dm of the fatal head is encircles by the vulval ring

episiotomy

27
Q

what are the components of the bishop score

A
position 
consistency 
effacement 
dilatation 
station in pelvis
28
Q

analgesia in labour

A
paracetamol/co codamol 
TENS
entonox
diamorphine 
epidural 
remifentanyl 
combined spinal/epidural
29
Q

blood loss normal

abnormal

A

<500mls normal

>500mls not normal

30
Q

plane of separation of placenta
mechanics of placental separation
method of separation

A

spongy layer of decidua basalis

shearing force

methew duncan marginal most common type of separation

31
Q

3 signs that indicate placental separation

how long does it take

A

uterus contracts, hardens and rises
umbilicord cord lengthens permanently
gush of blood variable in amount

5-10 mins after delivery, normal up to 30 mins

32
Q

how is homeostasis achieved

A

tonic contraction - lattice pattern of uterine muscle strangulates the blood vessels

thrombosis of the torn vessel ends - pregnancy is a hyper coaguable state

myo tamponade opposition of the anterior/posterior walls

33
Q

what is a puerperium

how long does it last

A

period of repair and recovery

6w

34
Q

what consists of puerperium

A
return of tissues to non pregnant state 
loch - vaginal discharge containing blood, mucus and endometrial castings 
rubra (fresh blood)
serosa - brownish red watery 
alba - yellow 
uterine involution 
weight reduces 
fundal height - umbilicus within pelvis in 2 weeks 
endometrium regenerates by a week 
diuresis commences 2-3 days post natally
35
Q

physio in puerperium

A

lactation initiated by placental expulsion
decrease in oestrogen and prog
prolactin is maintained
colostrum rich in immunoglobulin - long term protective effect for the baby