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Flashcards in Preterm Labour Deck (45)
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1

What is the definition of late preterm labour?

34-37/40

2

What is the definition of early preterm labour?

<34/40

3

What is the definition of very preterm labour?

28-32/40

4

What is the definition of extreme preterm labour?

<28/40

5

What proportion of PTB is iatrogenic?

20%

6

What are four possible mechanisms for spontaneous PTL?

1. Premature activation of maternal or fetal HPA axis
2. Exaggerated inflammatory response or infection
3. Decidual haemorrhage
4. Pathological uterine distension

7

What are the risk factors for PTB (20!)

Previous PTB (15-30% recurrence, usually at same gestation)
Multiple gestation
IVF
Uterine anomaly including fibroids
Previous cervical surgery
PPROM
Previous 2nd trimester abortion
Polyhydramnios
Genital tract infection
Asymptomatic bacteruria
Systemic infection
Maternal chronic disease
APH - 1st trimester / praevia / abruption
Smoking
Extremes of age
Anaemia
IUGR
Fetal anomaly (or demise)
Social factors
Genetic factors

+ CS at fully

8

At what gestation (of prematurity) should you NOT do FBS and FSE?

< 34/40

9

What is bronchopulmonary dysplasia?

Oxygen requirement at 28 days old or at 36/40
Multi factorial

10

What is apnoea of prematurity?

Central, obstructed or mixed
Desaturation and bradycardia
Immaturity of central respiratory drive

Treat with caffeine

11

What is periventricular leukomalacia?


What is it associated with?

Hypoxia of watershed areas of brain white matter

Associated with cerebral palsy - spasticity and neurodevelopmental delay

12

What are 13 complications of prematurity?

RDS
Apnoea of prematurity
TTN
BPD
NEC
PDA
Feeding intolerance
IVH
PVL
Sepsis

Hypothermia
Hypoglycaemia
Jaundice

13

What was the finding of the Cochrane review looking at
- prenatal administration of progesterone to prevent PT in women considered to be at risk of PT

Benefits in prolonging pregnancy and in infant health

14

`What was the finding of the Cochrane review looking at
- combinations of tocolytic drugs for inhibiting PTL?

Unclear whether combination therapy better than single tocolytic therapy

15

What was the finding of the Cochrane review looking at
- Calcium channel blockers for inhibiting PTL?

Benefits over placebo with regard to
- prolongation of pregnancy
- serious neonatal morbidity
- maternal adverse effects
but NO difference in perinatal mortality

Benefits over betamimetics, ORAs and MgSO4

16

What was the finding of the Cochrane review looking at
- antibiotics for asymptomatic bacteruria in pregnancy?

May be effective in reducing risk of pyelonephritis in pregnancy
MAY be a reduction in PTB and LBW with antibiotics

2019

17

What was the finding of the Cochrane review looking at
- antibiotics for BV in pregnancy

Can eradicate BV, but overall risk of PTB was not reduced

18

What was the finding of the Cochrane review looking at
- effect of umbilical cord clamping in PTB

Delayed, rather than early cord clamping may reduce the risk of death before discharge for babies born preterm

19

At 23/40, what are the
- survival rates
- survival without major/minor morbidity

Survival rate - 55%
Survival without morbidity = 2.3%

20

At 24/40, what are the
- survival rates
- survival without major/minor morbidity

Survival: 70%
Survival without morbidity: 0%

21

At 25/40, what are the
- survival rates
- survival without major/minor morbidity

Survival rate: 78%
Survival without morbidity: 2%

22

What is the mechanism by which steroids help lung development?

Accelerated development of Type 1 and 2 pneumocystis
Leading to structural and biochemical changes that improve lung mechanics and gas exchange
Increases surfactant production
Induce pulmonary beta receptors, induce antioxidants and promote lung fluid absorption after birth

23

Until what gestation, should you consider rescue / repeat dose steroids?

32+6/40

24

What is the role of steroids prior to El LSCS

Can use “if there is known fetal lung maturity” past 34+6/40 (vague)

Current recommendation in NZ is not to give unless CS <39/40

25

What were the findings of the Cochrane Review looking at antenatal corticosteroids for accelerating fetal lung maturation in women at risk of PTB

Sep 2020
Updated Dec 2020

Single course of steroids reduces
- respiratory morbidity
- NEC
- death (perinatal and neonatal)

Probably reduces
- IVH (previously in above category)
- developmental delay

NO effect on
- birth weight
- maternal Chorioamnionitis, endometritis, mortality

26

What were the findings of the Cochrane Review looking at antenatal corticosteroids for preventing respiratory compromise after CS at term?

May
- reduce respiratory problems
- reduce NICU admission

Further studies required

27

What were the findings of the Cochrane Review looking at repeat antenatal corticosteroid doses for women at risk of PTB, for preventing respiratory distress?

Repeat dose helps
- respiratory distress
- “other serious health problems”

28

What are the 4 proposed mechanism of action of Mg in fetal neuroprotection?

Stabilisation of cerebral circulation
Stabilising neuronal membranes
Anti-oxidant effects to reduce apoptosis
Anti-inflammatory effects

29

What effect does cervical cerclage have on PTB in
Women with an incidental finding of a short cervix?

Decreases RR 0.74

30

What effect does cervical cerclage have on PTB in
Women with a short cervix and previous history of PTB

Decreases, RR 0.61