Stages of Labour

Question 1

what happens before labour starts?

Answer 1

Braxton hicks contractions
plug of mucous and blood falls out (bloody show) and/or amniotic sac ruptures (waters breaking) - triggers onset of true labour contractions

Question 2

what happens in true labour contractions

Answer 2

pull on thick tissue of the cervix causing it to efface (get thinner) and dilate to allow foetus to exit via cervix
originate in pacemaker of tubal ostia in uterus
synchronised waves spread downwards from ostia
become more intense and get longer as they progress

Question 3

normal foetal position at onset of labour?

Answer 3

longitudinal
cephalic presentation
occipito-anterior
flexed head

Question 4

change in ration of which hormones trigger labour?

Answer 4

oestrogen:progesterone

more oestrogen

Question 5

how is oestrogen involved in labour?

Answer 5

contracts the uterus
promotes prostaglandin production
facilitates gap junction formation in myometrium

Question 6

how is progesterone involved in labour?

Answer 6

keeps uterus settles
prevents gap junction formation in myometrium
hinders contractions

Question 7

what other things help initiate labour?

Answer 7

fergusons reflex
increase in oxytocin receptors
secretion of surfactant and foetal cortisol by foetus
increase in hyaluronic acid

Question 8

what is fergusons reflex?

Answer 8

neuroendocrine reflex where pressure exerted on cervix and vaginal walls sustains uterine contractions

Question 9

effect of oxytocin on labour?

Answer 9

initiates and sustains uterine contractions
acts on decidual tissue to promote prostaglandin release, phospholipiase C activity and increase in cytosolic calcium promoting uterine contractility

Question 10

effects of surfactant on labour?

Answer 10

stimulates prostaglandin synthesis

Question 11

effects of cortisol on labour?

Answer 11

stimulates increase in maternal oestrogen

Question 12

effects of hyaluronic acid?

Answer 12

decreases firmness of cervix

Question 13

latent phase of stage 1 labour?

Answer 13

can last a few days
beginning > 3/4cm dilated
mild irregular contractions
shortening and softening of cervix

Question 14

active phase of stage 1 labour?

Answer 14

4>10cm dilation (full dilation)
contractions become rhythmic and stronger
slow descent of the presenting part of the foetus

Question 15

what happens in stage 2 of labour?

Answer 15

delivery of baby

Question 16

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Answer 16

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Question 17

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Answer 17

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Question 18

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Answer 18

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Question 19

what are the 7 cardinal movements of labour?

Answer 19

engagement (3/5 head entered pelvis)
descent
flexion
internal rotation
crowning and extension
external rotation
expulsion

Question 20

normal discharge following delivery?

Answer 20

1st = lochia (blood mucous and endometrial castings)

rubra (fresh red blood) = for 3-4 days

serosa (brown-red, watery) = 4-14 days

alba (yellow discharge) = 10-20 days

Question 21

shouldn’t have blood following delivery after how many days?

Answer 21

14 days

Question 22

normal blood loss in labour?

Answer 22

<500ml

Question 23

what stops bleeding after delivery?

Answer 23

hypercoagulable state in pregnancy
contractions strangulate pregnancy
myo-tamponade opposition of anterior/posterior walls

Question 24

how does the body change in puerperium?

Answer 24

fundal height reduces to normal within 2 weeks
weight of uterus drops from 1000g to 50-100g
endometrium regenerates by end of week 1 (but not at placental site)
physiological diuresis commences week 2-3 post natal