Labour and Delivery 2

Question 1

What are the mechanical factors of labour? PPP

Answer 1

Powers
Passage
Passenger

Question 2

Which women have poor uterine activity?

Answer 2

nulliparous women and induced labours

Question 3

How often does the uterus contract during labour?

Answer 3

45-60 secs every 2-3 mins

Question 4

What allows distention of the cervix?

Answer 4

cervical dilation is prerequisite for delivery

dependent on contracts, pressure of fetal head on the cervix and ability of the cervix to soften and allow distension

Question 5

What are the factors affecting passenger descent?

Answer 5

attitude - degree of flexion of head on the neck
ideal - maximal flexion, vertex presentation
any extension results in larger diameter
brow presentation/face presentation if extended

Question 6

What is the ideal position of the fetal head?

Answer 6

ideal = OA

OP/OT more difficult, OT needs assistance

Question 7

How does the size of the head adapt during delivery?

Answer 7

moulding of the bones of head reduces diameters of head

Question 8

what is ‘show’?

Answer 8

pink/white mucus plug from cervix and/or rupture of membranes

Question 9

Describe the descent of the head into the pelvis

Answer 9

head enters the pelvis in the OT position
head descends and flexes as the cervix dilates
head rotates 90 degrees so that the face is facing sacrum and enters the OA position

Question 10

What are the two parts of the second stage?

Answer 10

passive stage - full dilation until head reaches pelvic floor and woman experiences desire to push

active stage - mother pushing, pressure of head on pelvic floor produces irresistible desire to bear down

Question 11

What happens to the head position after it has been delivered?

Answer 11

head rotates 90 degrees to adopt transverse position in which it entered the pelvis

anterior should delivery under the symphysis pubis

Question 12

What is the most common cause of slow progress in labour?

Answer 12

inefficient uterine activity

Question 13

How is inefficient uterine activity managed?

Answer 13

common in nulliparous women and in induced labour
support and mobility
if persisitent slow progress - ARM and then oxytocin

Question 14

What is hyperactive uterine action?

Answer 14

excessively strong/frequent/prolonged contractions
fetal distress as diminished blood flow
rapid labour

Question 15

What causes hyperactive uterine action?

Answer 15

placental abruption
with too much oxytocin
S/E of prostaglandin administration to induce labour

treatment depends on cause - can do C section

Question 16

Why should oxytocin be used with caution in nulliparous women?

Answer 16

uterus more prone to rupture

Question 17

What happens when babies present in OP position?

Answer 17

common disorder of rotation
labour often more painful - backache and early desire to push
if progress into labour normally no action needed as many foetuses rotate to OA spontaneously or deliver OP

Question 18

When is intervention needed in an OP presentation?

Answer 18

if labour slow - augmentation used

if prolonged active second stage, instrumental delivery usually achievable with rotation to OA

Question 19

How is OT presentation managed?

Answer 19

normal rotation incomplete, if vaginal delivery not achieved after 1hr of pushing then significant
rotation with traction needed for delivery to occur (usually ventouse)

Question 20

What is a brow presentation?

Answer 20

rare
complete extension of fetal head results in face being presenting part
fetal compromise more common

Question 21

What is face presentation?

Answer 21

complete extension of head results in face being the presenting part
fetal compromise more common
if chin posterior then c-section is needed

Question 22

What are the different pelvic variants?

Answer 22

gynaecoid - ideal (50-80%)
anthropoid - narrow inlet, transverse diameter less than AP (20%)
android - heart shaped inlet, funnelling shape to mid pelvis (5%)
platypelloid - oval shaped inlet persists within mid-pelvis (10%)

Question 23

What are the different methods of induction and augmentation of labour?

Answer 23

vaginal prostaglandin E2
amniotomy +/- oxytocin
natural induction - passing finger through cervix and stripping between membranes + lower segment of the uterus

Question 24

What are the indications for induction of labour?

Answer 24

prolonged pregnancy
prelabour term SROM
IUGR
Pre-eclampsia or diabetes in mother

Question 25

What are the contraindications to induction of labour?

Answer 25

acute fetal distress
where elective C-section is indicated
possible previous lower segment C-section

Question 26

What are the potential complications of induction/augmentation of labour?

Answer 26

C-section 
Other interventions in labour 
Longer labour 
Hyperstimulation 
PPH

Question 27

What does augmentation mean?

Answer 27

artificially strengthening of contractions in established labour

use in slow progress in nulliparous women