Labour

Front 1

What is the definition of true labour?

Back 1

false labour pains become more coordinated and regular or "show" is seen or cervix is at least 2cm

Front 2

How do you determine head station?

Back 2

= level of lwest fetal bony part (head or breech) in relation to imaginary line across ischial spines (-5 = more proximal, 0 - at ischial spines (engaged) +5 more distal)
Antepartum - how many fifths of the head are felt - Ifyou think you're at the widest part of the head it is 3/5

Front 3

What are the different types of rupture of membranes?

Back 3

Rupture of membranes
Premature - at least 1 hr prior to onset of labour
Prolonged premature - > 18 hours elapse between rupture of membranes and onset of labour
preterm - ROM occurring before 37 weeks gestation
Preterm premature - ROM before 37 weeks AND prior to onset of labour

Front 4

What investigations should be done to confirm rupture of membranes?

Back 4

Sterile speculum exam - pooling of fluid in the posterior fornix, may observe fluid leaking out of cervix on cough
Amniotic fluid turns nitrazine paper blue (alkaline; vaginal - acidic)
ferning (high salt in amniotic fluid evaporates, looks like ferns under microscope)
US to rule out fetal abnormalities - oligohydramnios is indicative of ROM

Front 5

Describe the 1st stage of labour?

Back 5

1
Latent:
- uterine contrasctions typically infrequent and irregular
- slow cervix dilation (usually 3-4cm) and effacement
- usually ROM at end of latent phase
Active phase
- rapid cervical dilation to full dilatation
- should increase by 0.5-1cm/hr for nulliparous woman
- painful, regular contractions, q2min, lasting 45-60 secs
- contractions strongest at fundus, weakest at lower segment
- unwise to push at this stage even if pt feels like it

Front 6

Describe the 2nd stage of labour?

Back 6

from full dilatation to delivery of the baby
Mother feels a desire to bear down and push with each contraction
Uterine contractions @ 2-5mins

Front 7

Describe the 3rd stage of labour?

Back 7

From birth of baby to placenta expulsion
Separation usually complete within 5 minutes but can last up to 30mins before intervention is indicated
2 methods - expectant or active
Active - give IM 10 IU Syntocin) when anterior shoulder is delivered or within 1-2 mins of the birth of the baby

Front 8

Describe the 4th stage of labour?

Back 8

First postpartum hour
Monitor vital signs and bleeding
repair lacerations
ensure uterus is contracted (palpate uterus and monitor uterine bleeding)

Front 9

What are the 4 signs of placental separation?

Back 9

Gush of blood
lengthening of the cord
uterus becomes globular
fundus rises

Front 10

Describe the cardinal movements of the fetus during delivery

Back 10

Engagement, descent, flexion (allows smallest diameter to present to the pelvis)
Internal rotation (to OA ideally)
Extension of the head as vertex passes public symphysis it extends to deliver
Restitution (external rotation) once the head is through the vagina to allow delivery of shoulders, anterior then posterior shoulder

Front 11

Describe the role of CTG?

Back 11

Cardiotocography
Doppler device which measures fetal heart rate
Establishes a baseline and shows variation in the HR during labour
Can be lost during contraction as the fetal position changes

Front 12

When should a fetal scalp electrode be used? How does it work?

Back 12

used if repetitive decels or difficulty in tracing externally with a doppler
Senses potential differences caused by depolarisation of fetal heart
More sensitive
CI: HIV, hepatiis, fetal thrombocytopenia

Front 13

What is a normal fetal HR?

Back 13

110-160
Any bradycardia below 90bpm for more than 2 mins is of concern and requires immediate action

Front 14

What are the reassuring aspects of a foetal trace?

Back 14

Baseline between 110-160
Beat to beat variability > 5bpm between contractions
At least 2 accelerations of at least 15 bpm over the baseline for at least 15 seconds every 10 mins
No form of deceleration (drop in bpm by 15 beats for more than 15 secs) is reassuring

Front 15

What is an early deceleration?

Back 15

Uniform shape with onset early in contraction and returns to baseline by end of contraction
Normal vagal response to head compression
Benign usually seen with cervical dilation of 4-7 cm

Front 16

What are variable decelerations?

Back 16

Variable in shape, onset, and duration
Most common type
Due to cord compression or forceful pushing with contractions
Benign unless repetitive, with slow recovery or when associated with other abnormalities of FHR

Front 17

What are late decelerations?

Back 17

Uniform shape with onset late in contraction, lowest depth after peak of contraction, return to baseline after end of contraction
must see 3 in a row with all the same shape to define a late deceleration
Due to fetal hypoxia, and acidemia, maternal hypotension or uterine hypertonus
usually an ominous sign of uteroplacental insufficiency

Front 18

What suggests a severe variable deceleration?

Back 18

Deceleration to < 60bpm
> 60bpm beflow baseline
> 60 s in duration with slow return to baseline

Front 19

When should foetal scalp blood sampling be used?

Back 19

Indicated when non-reassuring fetal hear rate is suggested by clinical parameters inc. heavy meconium, mod to severe abnormal FHR patterns

Front 20

What is a normal fetal pH
Which pH indicates fetal acidosis

Back 20

> 7.25
< 7.2 - acidosis - delivery indicated

Front 21

Describe the different types of pain relief used in childbirth?

Back 21

Nitrous oxide and oxygen (50:50); Give in an Entonox machine; Enhances GABA-A receptors, induces dopamine and antagonises NMDA receptors
Epidural (fentanyl and LA); most effective way of relieving pain; L3/L4 space; SE: dizziness, shivering, may increase duration of 2nd stage and increase operative deliveries, severe headache (dural tap)
Pudendal block - gives perineal anaesthesia - commonly used in forceps and vacuum delivery
Spinal - similar to epidural - bolus, one time dose - more common in c/s - SE: decreased sysetmic resistance --> hypotension --> decreased placental perfusion --> fetal bradycardia - can get maternal resp depression if drug affects diaphragm
GA - used in emergency C/S - risk of maternal aspiration, hypoxia to fetus and mother

Front 22

Describe the 4 degrees of perineal tears

Back 22

1. damage to the fourchette and vaginal mucosa and the underlining mm are exposed
2. the posterior vaginal wall and the perineal mm are torn but the anal sphincter is intact
3. the anal sphincter is torn but the rectal mucosa is intact
4. the anal canal is opened and the tear may spread to the rectum

Front 23

What is inducation of labour and how is it achieved?

Back 23

Is an intervention designed to artificially initiate uterine contractions resulting in progressive effacement and dilatation of the cervix and birth of the baby
1. Cervidil to ripen cervix
2. AROM
3. Syntocinon - to start contractions

Front 24

List the indications for induction of labour

Back 24

Gestation of at least 41 weeks
Evidence of fetal compromise (fetal growth restriction and/or non-reassuring fetal surveillance)
maternal medical conditions (diabetes, renal disease, hypertension, sig pulm disease, antiphospholipid syndrome etc)
pre-pabour rupture of membranes
chorioamnionitits
gestational diabetes with complications
multiple pregnancy
abruption
macrosomia (big baby)
fetal death in utero
Bishop score!

Front 25

What are the components of the bishop score

Back 25

Position (posterior, mid, anterior)
Consistency (firm, medium soft)
Effacement (0-80)
Dilatation
Station of the fetal head

Front 26

What does a bishop socre of < 5 mean?

Back 26

Chance of successful vaginal delivery can be only 50% with induction - need to give prostaglandin gel, pessary (cervidil) of misoprostol to "ripen" the cervix

Front 27

Describe the methods for cervical ripening?

Back 27

1. Intravaginal prostaglandin (Prostin gel): - long and closed cervix with no ROM
2. Intravaginal PGE2 (Cervidil) - long and closed cervix, may use if ROM
3. Misoprostol: synthetic methylated PGE1 (not commonly used)
4. Foley catheter placement - to mechanically dilate the cervix

Front 28

What does a bishop score > 7 indicate?

Back 28

A favourable cervix

Front 29

Describe the methods for induction of labour

Back 29

Amniotomy = artificial ROM to stimulate PG synthesis and secretion
Oxytocin (Syntocinon) -

Front 30

Potential complications for Oxytocin to induce labour

Back 30

hyperstimulation/tetanic contraction (may cause fetal distress or rupture of uterus)
uterine mm fatigue, uterine atony (may result in PPH)
vasopressin-like action causing anti-diuresis

Front 31

What is augmentation of labour

Back 31

Oxytocin to promote adequate contractions when spontaneous contractions are inadeuqate and cervical dilatation or descent of fetus fails to occur
To increase the rate of progress of spontaneous labour

Front 32

Risks of induction of labour

Back 32

Cord prolapse
uterine rupture
PPH
requiring an epidural
requiring an operative vaginal birth
requiring a caesarean section

Front 33

CI to induction

Back 33

Previous C/S
Previous uterine surgery
If you can't monitor patient
Placenta praevia or vasa praevia, cord presentation
fetal distress, malpresentation, preterm fetus without lung maturity

Front 34

Define the terms presentation and position

Back 34

Presentation: the part of the fetus lying over the pelvic inlet; the presenting body of the fetus
Position: the relationship of a given point on the presenting part of the fetus to a designated point of the maternal pelvis

Front 35

Describe the conditions which can prolong labour or delay labour?

Back 35

Prolonged labour > 48 hours
Fault of the power: (leading cause)
contractions (hypotonic, incoordinate), inadequate maternal expulsive efforts
Fault of the passenger
Abnormal position (e.g., OP), size of fetus, shoulder dystocia(after delivery of the head, the anterior shoulder cannot pass below the pubic symphysis)
Fault of the Pelvis:
reduced brim of pelvis; shape of sacrum; poor relaxation of pelvic ligaments
Psyche: hormones released in response to stress can bring about dystocia

Front 36

Describe the disorders that are involved in abnormal progression of labour (dystocia)

Back 36

Arrest disorder (arrest of dilatation or descent)
(Dilatation progress does not occur for > 2 hours in a patient who has entered the active phase
no progress in station for > 1 hr during 2nd stage)
Rx: if CPD ruled out - IV oxytocin and amniotomy can be attempted
Protraction disorder
( slope of cervical dilatation is < 1.2cm/h in primigravidas or < 1.5cm/hr in mulitgravidas; rate of descent of < 1cm/h in primigravidas or 2cm/hr in multigravidas)
Rx: oxytocin augmentation if contractions are inadequate +/- amniotomy
Prolonged latent phase
> 20 hrs in primigravidas or > 14 hrs in multigravidas during which labour has not progressed to the active phase
Most often due to false labour - rest and/or sedation
Rx: If labour is certain - oxytocin augmentation

Front 37

Describe the indications for use of an operative vaginal delivery (forceps or vacuum extraction)

Back 37

Fetal
- non-reassuring fetal status
- consider if 2nd stage is prolonged as this may be due to poor contractions or failure of fetal head to rotate
Maternal
- need to avoid voluntary expulsive effort (cardiac/cerebrovascular disease)
exhaustion, lack of cooperation and excessive analgesia may impair pushing effort

Front 38

Conditions necessary for use of forceps

Back 38

Full dilatation of cervix
Ruptured membranes
Engaged head at +2 station
knowledge of fetal position
No evidence of CPD
Adequate anaesthesia
Empty bladder

Front 39

Complications of forceps use

Back 39

Maternal:
anaesthesia risk; lacerations; injury to bladder, uterus, bone, pelvic nerve damage, PPH, infections
Fetal:
fractures, facial nerve palsy, trauma to face/scalp, intracerebral haemorrhage, cephalohaematoma, cord compression

Front 40

Complications of vacuum use for fetus

Back 40

subglial haemorrhage
subaponeurotic haemorrhage
soft tissue trauma
retinal haemorrhage

Front 41

Forceps vs vacuum?

Back 41

Forceps = higher rates of maternal trauma (perineal and vaginal lacerations), facial palsies
Vacuum = higher rates of neonatal injury ( cephalohaematomas, shoulder dystocia)
Rates of complications between 2 are not significant

Front 42

Describe the indications for a C/S

Back 42

Maternal:
obstruction, active herpetic lesion on vulva, invasive cervical cancer, previous uterine surgery or C/S, underlying maternal illness (eclampsia, HELLP syndrome, heart disease)
Maternal-fetal:
failure to progress, placental abruption or praevia
fetal: NRFHR, malpresentation (e.g., breech, transverse lie), cord prolapse, congenital anomalies

Front 43

Describe interventions to facilitate the delivery of the placenta

Back 43

1. Administration of uterotonic agents - oxytocin IM 10U with the birth of the anterior shoulder or within 2 mins of the birth of the baby
2. Controlled cord traction - clamp the cord within 2-3 mins of administration of an oxytocic
3. Uterine massage to make sure it is well contracted
4. As the placenta emerges gently turn it until the membranes are twisted

Front 44

Why are steroids given to Mum's with PPROM

Back 44

RDS
Decrease mortality
IVH
NEC

Front 45

When are steroids given to Mum's with PPROM

Back 45

2 doses
0 and 24 hours

Front 46

Why are antibiotics given to Mum's with PPROM
Which ones are given

Back 46

Decrease the frequency of maternal and fetal infections and delay the onset of labour
Give Erythromycin
If GBS +ve give penicillin or clindamycin (if pen allergy)

Front 47

What is the main tocolytic used in Australia?
What are some other examples

Back 47

Nifidipine - main one
Also: Mg Sulfate, B2 agonists, NSAIDs

Front 48

Describe the investigations used to determine ROM

Back 48

Visualise fluid coming out of cervical os
Nitrazine - test pH of vaginal fluid - amniotic 7-7.3; vaginal 3.8-4
Fern - glass slide - delicate ferning pattern cf. cervical mucous - thick and wide aborisation
US - low amniotic fluid volume