Labour

Question 1

What are the three stages of labour?

Answer 1

1 - from beginning of true contraction to 10cm dilated
2 =- delivery of foetus
3 - delivery of membranes

Question 2

What are the different processes of labour for the foetus?

Answer 2

1. Engagement -> widest foetal head in widest pelvis.
2. Descent
3. Flexion (to OA generally)
4. Internal rotation
5. Extension (as passes below maternal symphysis)
6. Restitution and external rotation (transverse postion so shoulder AP)
7. Expulsion

Question 3

What is the role of prostaglandins in labour?

Answer 3

Local hormone
Stimulates uterine contraction
Ripening cervix before delivery
Pessaries containing Prostaglandin E2 can be used to induce labour (dinoprostone)

Question 4

What are the Braxton Hix contractions?

Answer 4

Irregular infrequent contractions of the uterus
T2 + T3
Not induce labour
Do not progress and do not become regular
Staying hydrated and relaxing can help reduce pain.

Question 5

What key process occur in the first stage of labour?

Answer 5

Cervical dilation
Cervical effacement
Show - mucus plug drops out.

Question 6

What are the three phases of the first stage of labour?

Answer 6

Latent phase - up to 3cm dilated, 0.5cm per hour, irregular contractions
Active phase -> from 3 to 7cm, 1cm per hour, regular contractions
Transition phase - up to 10cm dilated, 1cm per hour, strong and regular contractions.

Question 7

What factors influence the success of the second stage of labour?

Answer 7

Power -> strength of contractions
Passenger -> size, attitude, lie, presentations,
Passage -> pelvis shape and size

Question 8

How can the stage of descent of the foetus during labour be described?

Answer 8

In relation to the ischial spines
-5 around pelvic inlet
0 at ischial spines
+5 out

Question 9

What is active management in terms of stage 3 of the labour?

Answer 9

Assisted delivery of the placenta
Reduce risk of bleeding -> done by request, in haemorrhage or more than 60 minute delay.
However can cause N+V

Question 10

What is the method of active management for delivery of the placenta?

Answer 10

Dose of IM oxytocin -> help uterus contraction and expel placenta
Gentle traction to the umbilical cord to guide the placenta out of the uterus and vagina.

Question 11

What gestation is considered a full term birth?

Answer 11

37-40w

Question 12

What hormones are involved in labour?

Answer 12

Stretching of cervix triggers oxytocin release from hypo -> post pit.
Placenta releases prostaglandins
Positive feedback loop

Question 13

What monitoring is normally recommended during labour?

Answer 13

FHR every 15mins or continuous CTG
Contractions every 30mins
Maternal HR every 60mins
Maternal BP and temp every 4hrs
VE 4hrs for progress
Maternal urine ketones and protein every 4hrs

Question 14

What assistance may be needed for stage 2 of labour?

Answer 14

CTG -> norm for fetal HR to decrease transiently
If longer than 1hr -> forceps, ventouse or section
Episiotomy after crowning
Epidural for pain

Question 15

What are the common indications for an induction of labour?

Answer 15

Prolonged pregnancy (after term)
Prelabour premature rupture of membranes
Maternal medical problems (diabetic mother >38 weeks, pre-eclampsia, obstetric cholestasis)
Intrauterine fetal death

Question 16

What is the purpose of a Bishop score in obsetrics?

Answer 16

Assess if induction of labour will be required
<5 likely requires induction
>=8 high chance of spontaneous labour

Question 17

How do you calculate a Bishops score?

Answer 17

Question 18

What are the different methods of inducing labour?

Answer 18

Membrane sweep
Vaginal PGE2
Oral PGE1
Maternal oxytocin infusion
Amniotomy
Cervical ripening balloon

Question 19

What is the purpose of membrane sweep?

Answer 19

Finger through cervix - rotate to seperate chorionic membranes from decidua
Used alongside induction
Nulliparus at 40/41w

Question 20

How does the Bishop score influence the preferred method of induction?

Answer 20

<= 6 vaginal prostaglandins or oral misprostol -> may use balloon catheter if previous section or risk of hyperstimulation

> 6 amniotomy and IV oxytocin

Question 21

What is the main complication of induction of labour?

Answer 21

Uterine hyperstimulation
Prolonged and frequent uterine contractions
Can interrupt blood flow to intervillous space -> foetal hypoxemia and acidemia or uterine rupture

Question 22

What is the management of uterine hyperstimulation?

Answer 22

Removing vaginal prostaglands/stop oxytocin infusion
Consider tocolysis

Question 23

What are the indications for a forceps delivery?

Answer 23

Fetal distress in second stage of labour
Maternal distress in second stage of labour
Failure to progress in second stage of labour
Control of head in breech deliver

Question 24

What decision may help decide if forceps of ventouse delivery are more appropriate?

Answer 24

36 or less = forceps as lower risk of scalp damage

Question 25

What are some risks to the baby after an assisted delivery?

Answer 25

Chignon -> from ventouse, will defined, immediatelty afer birth disappears within 48hrs Cephalohaematoma -> ventouse, disappear with time, over one bone, increase in first few hours, takes longer to heal Caput succedaneum -> oedema of presenting part due to pressure on cervix (can be in SVD), crosses suture lines, at birth Bruise from forceps Small cuts on scalp - 1 in 10 Jaundice -> blood breakdown if bruised.

Question 26

What are the two different types of c-section?

Answer 26

Lower segment - 99% Classic -> longitudinal incision in the upper segment of the uterus

Question 27

What are the different indications for a c-section?

Answer 27

Absolute cephalopelvic disproportion Placenta praevia 3/4 Pre-eclampsia Post-maturity IUGR Fetal distress in lanour/prolapsed cord Failure to progress Malpresentation Placental abruption - only if fetal distress Vaginal infection Cervical cancer

Question 28

What are the different categories of c sections?

Answer 28

C1 - immediate threat to life e.g uterine rupture, cord prolapse, fetal hypoxia or persistent bradycardia -> 30 mins C2 - compromise than is not immediately life-threatening -> 75 mins C3 - delivery required but mother and baby are stable C4 - elective.

Question 29

What are the serious risk of having a c-section?

Answer 29

Emergency hysterctomy Further surery if products retainined ITU admission VTE Blaader/ureteric injury Death (1 in 12,000)

Question 30

How can having a c-section affect future pregnancies?

Answer 30

Inc risk of uterine rupture Inc risk of antepartum stillbirth (one extra for 3,000) Inc risk placenta praevia and accreta More likely to need a c-section in the future

Question 31

What are some frequent risks from a c-section?

Answer 31

Wound and abdominal discomfort for few months Readmission to hospital -> haemorrhage, infection (wound, endometritis, UTI) Fetal lacerations

Question 32

What is the rate of success for a vaginal delivery after a c-section?

Answer 32

If >37w and only one previous c-section 75% will have success vaginal delivery Contraindicated if classic c-section scar or previous uterine rupture.

Question 33

When is labour considered prolonged (dystocia)?

Answer 33

More than 20hrs for nulliparis 14hrs for multigravida

Question 34

What are some common causes of prolonged labour?

Answer 34

Slow cervical dilation +/- descent Cephalopelvic disproportion Fetal malpresentation Macrosomia Anomalies in birth canal Inefficient uterine contractions

Question 35

What are some of the risks of a prolonged labour?

Answer 35

Maternal exhaustion Postpartum haemorrhage or infection Fetal distress/hypoxia/acidosis

Question 36

In the UK what is the diagnostic criteria for prolonged labour in the first stage?

Answer 36

Latent -> 20hrs in nullparius, 14 in multi Active -> less than 2cm in 4 hrs or no change over 4hrs

Question 37

In the UK what is the diagnostic criteria for prolonged labour in the second stage?

Answer 37

Nulliparus -> more than 3hrs with reginal anaesthesia or 2hrs without Multiparus -> 2 hrs in regional anaesthesia or 1hr without

Question 38

What forms the initial assessment and management of prolonged labour?

Answer 38

1. maternal and foetal monitoring - CTG 2. Evaluate -> cervical dilation, presenting part, contractions and amniotic fluid status 3. US if needed -> malpresentation or malposition

Question 39

What are the potential management options for prolonged labour?

Answer 39

ARM IV oxytocin Pain - NO, epidural

Question 40

What surgical management can be considered for a prolonged labour?

Answer 40

Ventous or forceps -> particularly if fully dilated C-section -> if vaginal not safe

Question 41

What is the purpose of ergometrine in labour?

Answer 41

Used during third stage of labour Help stimualtes uterine contractions to prevent PPH Should not be given before the baby is delivered.

Question 42

What is a tocolytic? Give an example.

Answer 42

Drug to suppressure uterine activity and delay the onset of labour For example: Nifedipine -> a CCB -> can also reduce blood pressure. Terbutaline -> beta-2-adrenergic antagonist

Question 43

What simple analgesia can be used in early labour?

Answer 43

Paracetamol Codeine may be added for an additional effect NSAIDS are avoided

Question 44

What is the purpose of entonox as pain relief during labour?

Answer 44

50% nitrous oxide and 50% oxygen Used during contractions for short term pain relief Taken at start of contraction Cautions: lightheadedness, nausea or sleepiness

Question 45

What opioids can be used as pain relief during labour?

Answer 45

Pethidine and diamorphine IM injections Can help with anxiety and distress Cautions: if too close to labour can cause resp distress and difficult first feed in neonate.

Question 46

What is the purpose of patient controlled analgesia during labour?

Answer 46

Remifentanil -> short acting opiod Bolus IV -> patient release at start of contraction Requires anaesthetics and available of naloxone for resp depression and atropine for bradycardia if needed.

Question 47

What is the reasoning/mechanism of an epidural during labour?

Answer 47

Catheter into the epidrual space Local anaesthetic given -> fentanyl mixed with levobupivacaine or bupivacaine. Diffuse into the surrounding tissue and the spinal cord.

Question 48

What are the adverse effects of an epidural?

Answer 48

Headache after insertion Hypotension Motor weakness in the legs Nerve damage Prolonged second stage Increased probability of instrumental delivery.

Question 49

What are some red flags that epidural administration have gone wrong?

Answer 49

Develop significant motor weakness such as unable to straight leg raise. Suggests catheter might be in the subarachnoid space (within the spinal cord).