Preterm Labour

Question 1

What is preterm labour

Answer 1

Onset of labour prior to 37 week gestation

Question 2

What are sub classification of pre term Labou?

Answer 2

Very preterm <32

Extremely preterm <28

Question 3

What is PTL correlated to?

Answer 3

Higher morbidity and mortality

Question 4

What are common short term issues in pre term babies

Answer 4

• Respiratory distress syndrome
• Intraventricular haemorrhage > neurological deficit
• Paraventricular leukomalacia
• Necrotising enterocolitis
• Sepsis
• Retinopathy

Question 5

What are key RF for preterm birth?

Answer 5

Prior preterm birth
Prior second trimester loss
Prior cervical biopsy / intervention

Question 6

Why is second trimester loss important in PTL and not first trimester loss?

Answer 6

Because first trimester loss is likely due to genetic / chromosomal foetal abnormalities

Second trimester instead is more likely that the foetus is normal and the cervix is unable to hold it in

Question 7

What are secondary RF for PTL?

Answer 7

• Immunological e.g. infection, vaginal microbiome
• Mechanical e.g. fibroids, multiple pregnancy (push down on baby)
• Structural (uterine abnormality)
• Social (smoking, drugs, age, BMI extremes)

Question 8

What are common infections linked to PTL?

Answer 8

BV
UTI
Chlamydia / gonorrhoea

Question 9

Why do UTIs commonly occur in pregnancy?

Answer 9

Due to relaxation of SM

Question 10

What are examples of cervical interventio ns that trigger cervical weakness?

Answer 10

LLETZ 
Cone biopsy (NOT punch biopsy, as that is too small)

Question 11

What does PTL present with?

Answer 11

Regular uterine contractions
Leaking amniotic fluid
PV bleed
Worsening lower back pain

Question 12

What is very important to test during suspected PTL?

Answer 12

Take cervicovaginal fluid level of FOETAL FIBRONECTIN

fFN

Question 13

What is fFN?

Answer 13

A glycoprotein produced by chorionic membranes as you are approaching labour

Question 14

What are boundaries of ffN and what does it indicate?

Answer 14

fFN <50 gives a NEGATIVE result, so chance of delivering in next week is <1%

fFN >50 is POSITIVE RESULT (so admit, potential tocolysis etc.)

Question 15

What are tocolytics?

Answer 15

Medications that delay labour for long enough to give corticosteroids and magnesium sulphate

Question 16

What Is the common tocolytic given?

Answer 16

Nifedipine (calcium channel blocker)

Inhibits calcium influx into cells > prevents SM contraction

Question 17

Why must you not give beta agonists as tocolytics

Answer 17

Because they have important maternal side effects e.g. pulmonary oedema

Question 18

Why must you not give NSAIDS as tocolytics?

Answer 18

NSAIDS inhibit prostaglandins

this causes::

• premature closure of ductus arteriosus
• leads to persistent pulmonary hypertension

Question 19

When are corticosteroidfs given in PTL?

Answer 19

24-34 week gestation

Question 20

How many doses of corticosteroids must be given?

Answer 20

2 doses 24h apat

Question 21

How long does corticosteroid benefit last fo?

Answer 21

2 to 7 days

Question 22

What are corticosteroids to give in PTL

Answer 22

‘Dexamethasone

Question 23

What do you need to keep in mind if giving steroids in PTL mother?

Answer 23

That steroids increase WCC

This means there is an increased risk of confusion if the mother is infection

Question 24

What is a negative effect of giving repeated doses of steroids on the foetus?

Answer 24

Impact baby IQ

Question 25

What other dug would you consider in PTL with PPROM?

Answer 25

Antibiotics

10 day course of erythromycin

Question 26

How do you predict risk of preterm delivery?

Answer 26

Based on Past Obstetric Hx (prior PTD)

Based on cervical length measured on TVUSS (short cervix > high risk)

Question 27

When would you perform a rescue cerclage?

Answer 27

At 16-24 weeks, if cervix is dilated (with exposed membranes) but membranes are intact and there are no contractions

Question 28

Why myst you not consider rescue cerclage is membranes are ruptured?

Answer 28

Because infection had spread to abdomen

There is likely chorioamnionitis developing

Question 29

When would you do an US indicated cerclage?

Answer 29

When cervix shortens <25 mm in women with history of cervical surgery / prior PTD

Question 30

What is PPROM?

Answer 30

Ruptured membranes <37 weeks with not uterine contractions

Question 31

How is delivery related to PPROM?

Answer 31

Most deliveries occur in next 24h

Question 32

What is PPROM diagnosed qwith?

Answer 32

Clinical history

Pool of liquor in vagina on speculum

Question 33

How do you treat PPROM?

Answer 33

Erythomycin 10 days

Expectant management unless evidence of chorioamniositis

Question 34

What is chorioamniositis

Answer 34

infection of foetal membranes, usually coming from vaginal canal

Question 35

What are symptoms / signs of chorioamniositis

Answer 35

Offensive liquor 
Yellow / green liquor 
Maternal tachycardia 
Temp >37.5
High CRP >40 
Tender uterus, increased uterine activity CTG shows high foetal HR

Question 36

What is the function of magnesium sulphate ?

Answer 36

Neuroprotector

Reduces risk of cerebral palsy

Question 37

when do you perform foetal fibronectin

Answer 37

if suspecting preterm labour

and TVUSS is not available/not approprite

Question 38

What. are important considerations for delivery method in PTB

Answer 38

C section is harder in preterm birth - increased ilkelyhood of vertical incition