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Flashcards in Normal Labour and Puperium Deck (60):
1

What is labour?

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

2

What is labour associated with?

Regular, painful uterine contractions with increasing frequency, intensity and duration
Biochemical changes in cervical tissue allowing cervical effacement and cervical dilatation resulting in delivery of the fetus and expulsion of the placenta

3

What are the 3 key factors in labour?

Power: uterine contration
Passage: maternal pelvis
Passenger: fetus

4

What is the role of progesterone in labour?

Keeps uterus settled
Prevents the formation of gap junctions
Hinders the contractibility of myocytes

5

What is the role of oestrogen in labour?

Makes uterus contract
Promotes prostaglandin production

6

What is the role of oxytocin in labour?

Initiates and sustains contractions
Acts on decidual tissue to promote prostaglandin release

7

Where is oxytocin synthesised?

Directly in decidual and extraembryonic fetal tissues and in the placenta
The number of oxytocin receptors increases in myometrial and decidual tissues near end of pregnancy

8

What occurs in the initiation of labour?

Degree of uncertainty
Change in the estrogen/progesterone ratio
Fetal adrenals and pituitary hormones may control the timing of the onset of labour
Myometrial stretch increases excitability of myometrial fibres
Mechanical stretch of cervix and stripping of fetal membranes
Fergusons Reflex

9

What are some other known causes of possible labour initiation?

Pulmonary surfactant secreted into amniotic fluid- reported to stimulate prostaglandin synthesis
Increase in production of fetal 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

10

What occurs in the latent phase of the first stage of labour?

Mild irregular uterine contractions, cervix shortens and softens, duration variable of up to a few days. 3-4cm dilatation

11

What occurs in the active phase of the first stage of labour?

4cm onwards to full dilatation
Slow descent of presenting part
Contractions progressively become more rhythmic and stronger

12

What happens in the second stage of labour?

Complete dilatation of cervix (10cm) to delivery of baby
Nulliparous women considered prolonged if it exceeds 3 hours if regional anaesthesia, 2 hours without
Multiparous: 2 hours with ra, 1 without
In low risk care vaginal exam not always carried out

13

What happens in the third stage of labour?

Delivery of baby to expulsion of placenta and fetal membranes
Average duration 10 minutes, can be 3 or longer
After 1 hour prep made for removal under GA
Active management: use of oxytocic drugs and controlled cord traction is preferred for lowering risk of post partum haemorrhage

14

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

Prophylactic administration of Syntometerine: 1ml ampoule containing 500mg ergometrine maleate and 5IU oxytocin OR oxytocin 10 units
Cord clamping + cutting
Controlled cord traction
Bladder emptying

15

What cervical softening occur in labour?

Cervical softening:
Increase in hyaluronic acid gives increase in molecules among collagen fibres
The decrease in bridging among collagen fibres gives decrease in firmness of cervix.

16

What cervical ripening occurs in labour?

Cervical ripening:
Decrease in collagen fibre alignment
Decrease in collagen fibre strength
Decrease in tensile strength of the cervical matrix
Increase in cervical decorin (dermatan sulphate proteoglycan 2)

17

What are Braxton Hicks contractions?

Tightening of uterine muscle, thought to aid the body prepare for birth
Can start 6 weeks in, usually not felt until 2nd or 3rd trimester
Irregular
Can thin the cervix, but won't lead to delivery

18

What is a true labour contraction?

Wave
Pain starts low, rises until it peaks, and finally ebbs away. Mothers abdomen will be hard during contraction
Start about 5 minutes apart

19

How do Braxton Hicks contractions resolve?

Ambulation or change in activity

20

What do contractions do to your uterus and cervix?

Tighten top part of uterus pushing baby downward into birth canal
Promotes thinning of cervix

21

Describe contraction timing

Start infrequently and may be noticed at 10-15 minute intervals
Get longer and more intense feeling

22

What accompanies contractions?

Cervical changes, softening, effacement and dilatation

23

Describe the uterine muscle

Smooth muscle (myocyte) in connective tissue (collagen and elastin)
Density highest at fundus

24

Describe cervical tissue

Collagen tissue mainly (types 1,2,3,4), smooth muscle, elastin
Held together by connective tissue ground substance

25

Where is the pacemaker of the uterus and cervix?

Region of tubal ostia
Wave spreads in a downward direction

26

Do both ostia synchronise?

Yes

27

Describe the polarity of contractions

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

28

Describe the intensity of contractions?

Degree of uterine systole
Max in second stage
Grades: mild, moderate, strong

29

What is the frequency and duration of contractions?

Normal up to 3-4 in 10 minutes
Allows time for resting tone
Initially 10-15 secs, max 45

30

What is an anthropoid pelvis?

There is an oval shaped inlet with large anterio-posterior diameter and comparatively smaller transverse diameter

31

What is an android pelvis?

Android shaped pelvis has triangular or heart-shaped inlet and is narrower from the front. African-Caribbean women are more at risk of having an android shaped pelvis

32

What is the most suitable female pelvic shape?

Gynaecoid pelvis

33

What is the liquor?

Nurtures and protects fetus and facilitates movement

34

What is the normal position during labour?

Longitudinal lie
Cephalic presentation
Presenting with vertex
OA- head engages occipito-transverse
Flexed head

35

What are the stages of delivery?

Engagement
Descent
Flexion
Internal Rotation
Crowning and extension
Restitution and external rotation
Expulsion, anterior shoulder first

36

How often should vaginal examinations be carried out during labour?

Approximately every 4 hours
Should not be carried out inappropriately just for information

37

What is crowning?

Appearance of a large segment of fetal head at the introitus

38

How stretched will labia be during crowning/

To full capacity

39

What is the largest diameter of the fetal head encircled by during crowning?

Vulval ring

40

What parameters can be used to characterise the cervix during labour?

Effacement
Dilatation
Firmness
Position
Level of the presenting part

41

What are the 5 elements of the Bishop score?

Position
Consistency
Effacement
Dilatation
Station in Pelvis

42

What is the Bishop score?

Best and simplest method available to determine if it is safe to induce labour

43

What are some analgesia options during labour?

Paracetamol/ Co-codamol
TENS
Entonox
Diamorphine
Epidural
Remifentanyl
Combined spinal/epidural

44

What is a normal blood loss in pregnancy?

Volume of less than 500ml

45

What is an abnormal blood loss in pregnancy?

Volume greater than 500ml
More significant if greater than 1500ml
At blood loss prior to delivery apart from 'show' is abnormal, and requires consultant unit referral

46

What is the plane of placental separation?

Spongy layer of decidua basalis

47

What are the methods of placental separation?

Matthew Duncan: marginal, the most common type of separation
Schultz: separation from central aspect

48

What 3 signs indicate placental separation?

Uterus contracts, hardens and rises
Umbilical cord lengthens permanently
Gush of blood variable in amount

49

When does expulsion of the placenta normally occur?

5-10 mins after delivery
Normal is up to 30 mins

50

How is haemostasis achieved in placental separation?

Tonic contraction: lattice pattern of uterine muscle strangulates the blood vessels
Thrombosis of the torn vessel: pregnancy is hyper-coagulable state

51

What is puerperium?

Period of repair and recovery to non-pregnant stae

52

How long does puerperium last?

6 weeks

53

What is lochia?

Vaginal discharge containing blood, mucus and endometrial castings
Rubra (fresh red)
Serosa (brownish red, watery)
Alba (yellow)

54

What happens to the uterine weight in uerperium?

~1000g reduces to 50-100g

55

What fundal height change occurs in puerperium?

Goes from umbilicus to within pelvis in 2 weeks

56

How long does the endometrium take to regenerate following pregnancy?

End of a week (except placental site)

57

What structures regress but never go back to pre-pregnancy state?

Cervix
Vagina
Perineum

58

When does diuresis commence postnatally?

2-3 days

59

What is lactation initiated by?

Placental expulsion

60

What hormonal changes occur in puerperium to influence lactation?

Decrease in oestrogen and progesterone
Prolactin is maintained