Physiology and Stages of Labour

Question 1

Describe stage 1 of labour.

Answer 1

Cervical dilatation occurs in preparation for passage of the fetus (becomes active at 4cm)

Question 2

Describe stage 2 of labour.

Answer 2

Commences when dilatation achieves its full capacity (10cm)

Ends with the delivery of the baby

Question 3

Describe stage 3 of labour.

Answer 3

Delivery of placenta and fetal membranes, normally lasts under 10 mins

Question 4

How many contractions normally occur in 10 mins?

Answer 4

3-5

Question 5

What is the attitude?

Answer 5

the degree of flexion/extension of fetal head

Question 6

When is the fetal head optimally flexed?

Answer 6

smallest possible diameter arrives at the pelvic inlet

Question 7

3 Ps?

Answer 7

power
passage
passenger

Question 8

Which hormone keeps the uterus settled, and prevents formation of gap junctions?

Answer 8

progesterone

Question 9

Which hormone makes the uterus contract, promoting prostaglandin production?

Answer 9

estrogen

Question 10

What initiations and sustains contractions?

Answer 10

oxytocin

Question 11

What ratio change initiates labour?

Answer 11

progesterone:oestrogen

Question 12

What happens to fetal cortisol in labour?

Answer 12

increases

Question 13

Active management of stage 3?

Answer 13

give prophylactic oxytocin

Question 14

Why is the clinician’s hand used to control delivery?

Answer 14

prevents precipitous expulsion, which could cause intracranial haemorrhage

Question 15

What should be done to the umbilical cord?

Answer 15

should be double clamped and cut

Question 16

What should also be recorded at stage 3?

Answer 16

no of blood vessels of umbilical cord

Question 17

What are Braxton Hicks contractions?

Answer 17

no true labour - can start as early as 6 weeks into pregnancy, not usually felt until 2nd/3rd trimester.

Question 18

Are BH contractions regular?

Answer 18

no, and no not increase in frequency or intensity

Question 19

How are true labour contractions described?

Answer 19

waves

Question 20

What is released to cause true labour contractions

Answer 20

oxytocin

Question 21

What happens to cervix as contractions occur?

Answer 21

thinning

Question 22

What is the highest density area of the uterine muscle?

Answer 22

fundus

Question 23

How is haemostasis achieved?

Answer 23

• tonic contraction (lattice pattern of uterine muscle strangulates blood vessels)
• thrombosis of torn vessel ends
• myo-tamponade opposition of anterior/posterior walls

Question 24

Is pregnancy a hyper coagulable state?

Answer 24

yeah

Question 25

What is puerperium?

Answer 25

period of repair and recovery

Question 26

What may occur during the 6 weeks of puerpium?

Answer 26

Lochia - vaginal discharge containing blood, mucus and endometrial castings

Question 27

When does the endometrium regenerate by?

Answer 27

end of a week (except placental site)

Question 28

What initiates lactation?

Answer 28

placental expulsion

Question 29

What happens to oestrogen, progesterone and prolactin?

Answer 29

oes and prog decrease, prolactin is maintained