Obstetrics - Intrapartum

Question 1

Pelvic inlet and outlet

Answer 1

Inlet (symphysis pubis, ileopectineal line, sacrum) - wider transvers
Outlet (lower symphysis pubis, ramus of pubic bone, ischial tuberosity, sacral ligament) - wider antero-posteriorly

Question 2

First stage of labour, 2 stages of this

Answer 2

From diagnosis (regular contractions bringing about cervical change) to full dilatation
1 - Latent - effacement and dilatation up to 3-4cm 3-8HRS
2 - Active - full dilatation 2-6HRS

Question 3

Second stage of labour, 2 stages of this

Answer 3

From full dilatation to delivery
1 - Passive - head high in pelvis, no maternal urge to push
2 - Active - maternal urge to push due to descending fetal head

Question 4

Third stage of labour

Answer 4

From delivery of fetus to delivery of placenta

Question 5

Active management of 3rd stage

Answer 5

IM oxytocin as anterior shoulder delivered
Early clamping and cutting
Controlled cord traction

Question 6

Passive/physiological management of 3rd stage

Answer 6

Delivered by maternal effort

Question 7

Mechanism of labour (8)

Answer 7

1 - engagement
2 - descent
3 - flexion - head flexes as descends into mid-cavity
4 - internal rotation - guided to rotate anteriorly by levator ani muscles
5 - extension - crowning
6 - restitution - as occiput escapes vulva, head aligns with shoulders
7 - external rotation - shoulders rotate into AP plane
8 - anterior shoulder delivered

Question 8

What constitutes abnormal labour (5)

Answer 8

Poor progress
Malpresentation
Uterine scar
Multiple gestation
Induction

Question 9

Define poor progress in 1st stage labour

Question 10

Causes of poor progress in 1st stage labour

Answer 10

Dysfunctional uterine activity
Cephalopelvic disproportion
Malpresentation
Abnormality of birth canal

Question 11

Define poor progress in 2nd stage labour

Answer 11

Birth not taken place within 3 hours of active second stage (pushing)

Question 12

Causes of poor progress in 2nd stage labour

Answer 12

Secondary uterine inertia

Narrow mid-pelvis

Question 13

Indications for induction (8)

Answer 13

Prolonged pregnancy
PROM
Fetal growth restriction
Pre-eclampsia
Deteriorating maternal illness
Unexplained haemorrhage
Diabetes
Intrahepatic cholestasis of pregnancy

Question 14

Contraindications to induction (5)

Answer 14

Placenta praevia
Severe foetal compromise
Breech
Prematurity
High parity

Question 15

Before offering induction…

Answer 15

offer membrane sweep

Question 16

Assessing suitability for induction

Answer 16

Bishop’s score (based on position of cervix, consistency of cervix, effacement, dilatation, foetal position)

Question 17

Methods of induction

Answer 17

Medical - prostaglandin gel/pessary

Surgical - ARM +/- oxytocin infusion

Question 18

Indications for operative delivery (5)

Answer 18

Foetal malposition
Foetal distress
Maternal exhaustion
Prolonged second stage
Maternal medical conditions

Question 19

Requirements for operative delivery (5)

Answer 19

Confirmed ROM
Full dilatation
Vertex presentation
Adequeate analgesia/anaesthesia
no obstruction below foetal head

Question 20

Forceps delivery

Answer 20

Non-rotational (Neville-Barnes)
Rotational if head >15 degrees from vertical (Kielland)
More likely to cause maternal trauma
Not suitable

Question 21

Ventouse delivery

Answer 21

Not suitable

Question 22

Indications for LCSC (6)

Answer 22

Previous C section
Dystocia
Malpresentation
Suspected acute foetal compromise
?Multiple pregnancy
?Placenta praevia

Question 23

Complications of LSCS (6)

Answer 23

Bowel damage
Uncontrollable haemorrhage
Placenta praevia in next pregnancy
Urinary tract damage
Infection/endometriosis
PE/DVT