10/11) Labour & Delivery - PTB

Question 1

Prevention of PTB:

(1) History of PTB + short CL
(2) History of PTB + normal CL
(3) History of 2nd trimester miscarriage + short CL
(4) History of 2nd trimester miscarriage + normal CL
(5) No history + short CL
(6) History of PPROM + short CL
(7) History of cervical trauma + short CL

Answer 1

(1) OFFER Suture or progesterone
(2) CONSIDER progesterone
(3) OFFER Suture or progesterone
(4) CONSIDER Progesterone
(5) CONSIDER Progesterone
(6) CONSIDER Suture
(6) CONSIDER Suture

Question 2

When to consider rescue cerclage?

Answer 2

16-27+6 with dilated cervix, intact membranes and no bleeding/infection/contractions

Question 3

How to diagnose PTL?

Answer 3

If <30 weeks - Treat as TPTL

If >30 weeks

(1) Cervical length scan - if <15mm treat as PTL
(2) If cervical length scan unavailable then do fFN - if >50 treat as PTL
(3) If neither available - treat as PTL

Question 4

First line tocolysis

Answer 4

Nifedipine

Question 5

When to offer tocolysis?

Answer 5

Consider 24-25+6

Offer 26+0-33+6

Question 6

When to offer steroids?

Answer 6

Discuss 23-23+6
Consider 24-25+6
Offer 26+0-33+6
Consider 34+0-35+6

Question 7

When to offer MgSO4?

Answer 7

Offer 24+0-29+6

Consider 30+0-33+6

Question 8

Monitoring during PTB

Answer 8

Offer either CTG/IA
Try to avoid FSE <34 weeks and ideally <37
No FBS <34, discuss it up to 37

Question 9

When to consider CS for breech PTB?

Answer 9

Consider 26+0 onwards

Question 10

How long to delay cord clamping for?

Answer 10

Ideally 30s-3 minutes if mother and baby well but otherwise milk cord and clamp immediately.

Question 11

Indications for trans abdominal cervical cerclage

Answer 11

• Grossly disrupted cervix
• Absent vaginal cervix
• Previous failed elective vaginal cerclage

Question 12

Successful pregnancy rate for trans abdominal open cervical sutures

Answer 12

85%

Question 13

Timing of trans abdominal cerclage to improve outcomes

Answer 13

Pre-pregnancy

Question 14

Fetal loss rate associated with trans abdominal cerclage

Answer 14

6%

Question 15

Conversion rate to laparotomy for laparoscopic abdominal cerclage

Answer 15

10%

• 1st: Due to bleeding uterine vessels
• 2nd: Due to poor visualisation from obesity

Question 16

Incidence of preterm birth

Answer 16

10%

Question 17

What is cerebral palsy the most common cause of?

Answer 17

Severe physical disability in childhood

Question 18

What is the most common pattern of CP seen secondary to prematurity?

Answer 18

Diplegia

Question 19

What percentage of cases of CP are due to preterm delivery?

Answer 19

35%

Question 20

What percentage of cases of CP due to preterm delivery have experienced a perinatal insult?

Answer 20

49%

Question 21

What are the two patterns of CNS injury underlying CP?

Answer 21

• Intraventricular haemorrhage

- Periventricular leucomalacia (white matter injury)

Question 22

What is the main CNS injury affecting preterm infants with CP?

Answer 22

Periventricular leucomalacia

Question 23

What percentage of infants <1500g have PVL?

Answer 23

2-3%

Question 24

What percentage of infants <1500 with PVL will later develop CP or cognitive/behavioural defects?

Answer 24

10% CP

50% cognitive and behavioural defects

Question 25

What percentage of preterm infants show impairments in fine motor skills?

Answer 25

40-60%

Question 26

What percentage of infants have developmental coordination disorder?

Answer 26

18%

Question 27

What percentage of infants have visual impairment?

Answer 27

3% (50% if PVL)

Question 28

What percentage of infants have hearing impairment?

Answer 28

2%

Question 29

Risk of CP at term, 32-37 weeks, 28-31 weeks and 22-27 weeks?

Answer 29

Term: 0.1% 32-37 weeks: 0.7% 28-32 weeks: 6.2% 22-27 weeks: 14.6%

Question 30

What percentage of women receiving MgSO4 experience side effects?

Answer 30

70%

Question 31

What are the main side effects of MgSO4?

Answer 31

Hypotension + tachycardia, facial flushing, nausea + vomiting.

Question 32

Benefit of MgSO4

Answer 32

Reduced risk of cerebral palsy and substantial gross motor dysfunction

Question 33

NNT with MgSO4 at <30 weeks and 32-34 weeks

Answer 33

<30 weeks: NNT 46 | 32-34 weeks: NNT 56

Question 34

How much MgSO4 aiming for before delivery?

Answer 34

4 hours

Question 35

Which gestations are referred to by "threshold of viability"?

Answer 35

22+0 to 25+6

Question 36

Percentage of live births at each gestation 22-26 weeks

Answer 36

Overall: 87% live birth rate ``` 22 weeks: 55% 23 weeks: 80% 24 weeks: 90% 25 weeks: 95% 26 weeks: 98% ```

Question 37

Percentage of 28 day survival at each gestation 22-26 weeks

Answer 37

Overall: 57% ``` 22 weeks: 3% 23 weeks: 25% 24 weeks: 50% 25 weeks: 75% 26 weeks: 80% ```

Question 38

What antibiotics should be given to PTB?

Answer 38

IV Ben Pen

Question 39

Likelihood of classical CS being required at 24/28/30 weeks gestation

Answer 39

24 weeks: 20% 28 weeks: 10% 30 weeks: <5%

Question 40

What is the threshold birthweight?

Answer 40

<500g only resus after very careful consideration

Question 41

Monitoring in labour with extreme prematurity?

Answer 41

Only if you are going to act on abnormalities

Question 42

Incidence of head entrapment with breech 24-27 weeks

Answer 42

10% Vaginal | 5% CS

Question 43

Delayed cord clamping in extreme prematurity?

Answer 43

Milking cord x 4 has similar benefits