VBAC (RANZCOG)

Question 1

Incidence of LSCS in Australia and NZ?

Answer 1

33% Aus, 25.5% NZ 2015

Question 2

Prepregnancy advice to increase success and safety of VBAC?

Answer 2

IP interval of 18 months

weight reduction

Question 3

Success rates of VBAC?

Answer 3

60-80% success Middlemore

43% Aus

Question 4

Factors favouring successful VBAC?

Answer 4

previous safe vaginal birth
previous successful VBAC (87-91%)
spontaneous onset labour
uncomplicated low risk pregnancy

Question 5

Factors reducing VBAC success?

Answer 5

Previous CS for dystocia
IOL
coexisting pregnancy/maternal conditions
BMI >30 (40%)
macrosomia >4kg
AMA
short stature
>1 CS
Postdates (RCOG)
low pre labour bishop score (RCOG)

Question 6

What is the difference in incidence of uterine rupture when BMI normal vs. >40? (RANZCOG)

Answer 6

0. 9% normal BMI

2. 1% BMI >40

Question 7

RDS risk VBAC vs. CS

Answer 7

RCOG
VBAC = 2-3%
CS = 4-6%

Question 8

difference in maternal mortality for VBAC or repeat CS?

Answer 8

VBAC = 0.004%
CS = 0.013%
RCOG

Question 9

Uterine rupture rate in unscarred vs. scarred uterus? (RANZCOG)

Answer 9

0. 5-2/10,000 deliveries in unscarred uterus
1. 005-0.02%

vs.

22-74/10,000 deliveries
0.2-0.7%

Question 10

risk of pathological fetal acidosis after uterine rupture (RANZCOG)

Answer 10

0.15% of VBAC

90% after uterine rupture.

Question 11

Risk of perinatal death with uterine rupture (RANZCOG)

Answer 11

4 per 10,000 (0.04%) 1/3 attributable to uterine rupture

Elective cs = <1/10,000 perinatal death

Risk after uterine rupture is 12% (UKOSS), 2-16% AHRQ

Question 12

risk of maternal death with uterine rupture (RANZCOG)?

Answer 12

UKOSS: 1.3% with uterine rupture.

RANZCOG: 0.02 per 1000 women attempting VBAC (2/100,000)
0.002%

Question 13

What is the risk of uterine rupture with previous classical Caesarean, inverted T or J incisions? (RANZCOG)

Answer 13

classical= 20-90/1000 (2-9%)
T or J= 19/1000 (1.9%)

(vs. 5-7/1000 for lower segment transverse)
(0. 5-0.7%)

Question 14

Incidence of placenta accreta in 1st, 2nd, 3rd, 4th, 5th 6th or more CS?

Answer 14

1= 0.24%
2= 0.31%
3= 0.57%
4= 2.1%
5= 2.3%
6 or more = 6.7%

Question 15

Complication rate of elective vs. emergency CS?

Answer 15

elective = 7%
emergency = 13.2%

Question 16

Rates of emCS after for VBAC in in induced, augmented, and spontaneous labour groups?

Answer 16

induced = 33% CS (at least)
augmented = 26% CS 
spontaneous = 18%

Question 17

Risk of uterine rupture with prostaglandin IOL? R

Answer 17

prostaglandin: 1.4-2.45%

Question 18

What is the risk of uterine rupture in women augmented with VBAC vs. no augmentation?

Answer 18

augmentation = 1.9%

no augmentation = 0.19%

Question 19

What is the risk of uterine rupture after foley balloon and ARM in VBAC?

Answer 19

6. 3/1000 women (0.8-22.4)

0. 63%

Question 20

Risk of uterine rupture with any induction method?

Answer 20

12/1000 (9-16)

1.2%

Question 21

What is the success rate of VBAC after second CS compared to after first? What are the rates of uterine rupture?

Answer 21

71% vs. 77% success

rupture rate 1.6% vs. 0.7%

Question 21

What is the success rate of VBAC after second CS compared to after first? What are the rates of uterine rupture?

Answer 21

71% vs. 77% success

rupture rate 1.6% vs. 0.7%

Question 22

What is the rate of mid trimester VBAC uterine rupture with misoprostol induction?

Answer 22

0. 04% no CS vs.

0. 28% CS

Question 23

Contraindications to VBAC?

Answer 23

T or J incisions.
Previous uterine surgery (myomectomy)
Previous uterine rupture
placenta praevia

Question 24

VBAC success, uterine rupture rate and maternal morbidity after 2 previous CS?

Answer 24

1. success 71.1% 2. uterine rupture 1.36% 3. hysterectomy 56/10,000 (0.6%) vs. 19/10,000 (0.2%), 4. transfusion 1.99% vs. 1.21%

Question 25

What is the risk of maternal death with planned VBAC vs. elective CS?

Answer 25

4/100,000 VBAC (0.004%) | 13/100,000 planned CS (0.013%)

Question 26

What is the risk of transient respiratory morbidity in VBAC vs. elective CS?

Answer 26

2-3% VBAC | 4-5% LSCS

Question 27

Contrast foley IOL and prostaglandin induction for VBAC a) risk of uterine rupture b) success

Answer 27

Foley IOL +ARM a) 0.63% b) 54-61% Prostaglandin only a) 0.7-2.0% (up to 2.45%) b) 51-63% Prostaglandin + Oxytocin a) 1.8% (must be more) b) 60.2%

Question 28

Rate of VBAC success with EFW >4kg, no previous vaginal delivery?

Answer 28

Less than 50%, increased uterine rupture rate 3.6%

Question 29

Risk of hysterectomy when attempting VBAC?

Answer 29

0.5-2/1000 women attempting VBAC | 9% if uterine rupture occurs (UKOSS)

Question 30

Risk of genitourinary injury in women attempting VBAC?

Answer 30

0.8 per 1000 women attempting VBAC

Question 31

Risk of uterine rupture in term and post term IOL (RANZCOG)

Answer 31

``` term = 1.5% post-term = 3.2% ```

Question 32

Success rate of twin VBAC delivery?

Answer 32

3x small studies 64-76% no increase in scar rupture or perinatal morbidity largest study reported uterine rupture 0.9% success 45%

Question 33

Overall major maternal and perinatal morbidity in attempting VBAC?

Answer 33

``` perinatal = 1/1000 attempting VBAC maternal = 3/1000 attempting VBAC ```

Question 34

Risk of perinatal mortality postdates spontaneous VBAC?

Answer 34

1.8/1000 = 0.4 due to uterine rupture = 1.4 due to postdates Ranzcog guideline

Question 35

UKOSS perinatal morbidity and mortality after uterine rupture?

Answer 35

12% mortality 41% admitted nicu median 3 days 6% encephalopathy

Question 36

Risk of HIE VBAC vs. elective CS?

Answer 36

RCOG= VBAC= 0.08%. 60% due to uterine rupture. CS = <0.01%

Question 37

Risk of delivery prior to 39 weeks?

Answer 37

10%