Birth after previous Caesarean birth - GT45

Question 1

What is the CS rate in England?

Answer 1

25%

14.8% are emergency

Question 2

What are the absolute contraindications to VBAC?

Answer 2

Previous uterine rupture (>5% recurrent risk)
Previous Classical CS
Previous myomectomy if cavity breached
Placenta praevia
??2 previous CS

Question 3

What is the chance of placenta praevia in subsequent pregnancies?

Answer 3

1 CS - 1%
2CS - 1.7%
3CS - 2-8%

Question 4

What is the chance of placenta accreta in subsequent pregnancies?

Answer 4

Placenta praevia and 2 prev CS - 23-40%
Placenta praevia and 1 prev CS - 11-14%

Placenta praeva and =>5 prev CS - 67%

Question 5

What are the considerations for VBAC with 2 previous CS?

Answer 5

Rupture risk is fairly similar to 1 prev CS
Higher maternal morbidity
Similar VBAC rates but numbers skewed as >50% in study had previous VB
Hysterectomy rate increased
Transfusion rate increased
Need to take into consideration future fertility wishes - ie if planning more, risk of praevia etc with more CS

Question 6

What are the risk factors for uterine rupture?

Answer 6

• Delivery interval <12 months
• Postmaturity
• =>40yo
• Obesity
• Low prelabour Bishop score
• Macrosomia
• ?US-defined thin lower uterine segment
• Previous CS for dystocia

Question 7

What is the quoted success rate of VBAC?

Answer 7

72-75%

85-90% with previous vaginal birth

Question 8

What is the quoted risk of scar rupture with VBAC?

Answer 8

0.5%

Question 9

What is the risk of sphincter injury with VBAC?

Answer 9

5%

Question 10

What is the rate of instrumental delivery with VBAC?

Answer 10

39%

Question 11

What is the risk of maternal death with VBAC?

Answer 11

4 in 100,000

Question 12

What is the risk of scar rupture with elRCS?

Answer 12

<0.02%

Question 13

What is the risk of maternal death with elRCS?

Answer 13

13 in 100,000

Question 14

What is the risk of transient repiratory morbidity with VBAC?

Answer 14

2-3%

Question 15

What is the risk of transient repiratory morbidity with elRCS?

Answer 15

4-5%

6% if delivered at 38/40

Question 16

What is the risk of stillbirth beyond 39/40 with VBAC?

Answer 16

10 in 10,000 (similar to nullip)

Question 17

What is the risk of HIE with VBAC?

Answer 17

8 in 10,000

Question 18

What is the risk of delivery-related perinatal death in elRCS?

Answer 18

<1 in 10,000

Question 19

What is the risk of delivery-related perinatal death in VBAC?

Answer 19

4 in 10,000 (similar to nullip)

Question 20

What are the rates of uterine rupture in spontaneous labour, IOL and augmentation?

Answer 20

Spont - 0.15-0.4%
IOL - 0.5-1.4%
Augmentation - 0.9-1.9%

Question 21

What % of uterine rupture occurs intrapartum?

Answer 21

> 90% - peak 4-5cm
18% in 2nd stage
8% identified post-delivery

Question 22

Abnormal CTG is a feature in what % of uterine rupture events?

Answer 22

66-76%

Question 23

What is the risk of uterine rupture in an unscarred uterus?

Answer 23

0.02%, usually multiparous

Question 24

In what % can scar dehisence be asymptomatic?

Answer 24

48%

Question 25

By how much is the risk of rupture and repeat CS increased in IOL/augmentation with VBAC?

Answer 25

2-3x
Highest with prostaglandins vs mechanical methods
Repeat CS 1.5x

Question 26

By how much is the risk of stillbirth increased after 39/40 in women with a previous CS?

Answer 26

1.5-2x

Question 27

What is the success rate/uterine rupture of VBAC with an antepartum stillbirth?

Answer 27

87%

Rupture - 2.4%

Question 28

What is the % risk of blood transfusion following 3rd and 5th Caesarean section?

Answer 28

3rd - 8%

5th - 14%

Question 29

what are the risk factors for UNSUCCESSFUL VBAC, and what is the success rate if all these factors are present?

Answer 29

IOL
no previous vaginal delivery
BMI>30
previous c/s for dystocia
success rate=40%