3.6 - Preterm Labour and PPROM

Question 1

What is considered Preterm labour?

Answer 1

Labour <37 weeks
If <24 weeks => before viability => miscarriage

Question 2

What is the normal range for delivery?

Answer 2

37-42 weeks

Question 3

How do you predict Pre-term birth?

Answer 3

1) Partosure via endocervical swab
2) Transvaginal US checking for cervical shortening (<2.5cm)

Question 4

What does Partosure measure for

Answer 4

Foetal Fibronectin

Question 5

What is foetal fibronectin?

Answer 5

Glue like protein that binds foetal membranes. This sheds close to delivery (indicating glue is falling off) => should be absent from vaginal secretions until 36 weeks GA.

Note: It has a good negative predictive value => it can predict if there will not be a pre-term delivery rather than confirming there will be one

Question 6

How can you prevent Pre-term birth?

Answer 6

1) IM progesterone injections (33% success rate)
2) Cervical Cerclage
3) Tocolysis (only used for short term)

Question 7

What is Cervical Cerclage?
When is it typically performed?
Cervical cerclage isnt routinely performed. What patients should recieve this?

Answer 7

It is the prophylactic suturing of the cervix
typically performed at 14-16 weeks GA

Performed in patients with cervical incompetence => those with many LLETZ procedures for cervical cancer or a history of pre-term birth due to many reasons such as multiparity or Ehler Danlos

Question 8

Tocolysis should only be used for short term use. When are they used?

Answer 8

Tocolysis should only be used for short term delay. The only real use cases are:
1) Delay for enough time for steroids to be administered
2) Delay for transfer to a tertiary centre

Question 9

RF for Preterm delivery
Give 5 pregnancy related and 3 non-pregnancy related causes

Answer 9

Pregnancy-related:
1) Multiple Pregnancy
2) Premature rupture of membranes (Iatrogenic/pathologic)
3) Cevical incompetence (2 or more LLETZ procedures)
4) Placenta Previa
5) Placental Abruption
6) Polyhydramnios
7) Chorioamnionitis
8) Pre-eclampsia

Non-pregnancy related
1) Extremes of reproductive age
2) Smoking
3) Drug use
4) Uterine abnormalities
5) 2 or more LLETZ Procedures!

Question 10

Give the diagnostic definition of preterm labour
AKA including diagnostic parameters

Answer 10

Definition of Labour + Definition of Preterm =>
Regular painful contraction with cervical change and dilatation <37 weeks

Question 11

Give 5 consequences of Pre-term birth

Answer 11

1) RDS
2) NEC
3) IVH
4) Periventricular leukomalacia
5) PDA - Patent Ductus Arteriosis
6) Cerebral Palsy
7) Intellectual impairment/mental delay
8) Increased risk of sepsis
9) Neonatal jaundice

Question 12

Define PROM?
Define PPROM?
Define Prolonged PROM

Answer 12

PROM = Preterm rupture of membranes prior to onset of labour
PPROM = Preterm premature rupture of membranes <37 weeks prior to onset of labour
Prolonged rupture of membranes = ROM >24 hours

Question 13

Give 4 Ddx for a pregnant woman presenting at 35 weeks after experiencing a sudden gush of fluid

Answer 13

PPROM -Preterm, premature ROM
Urinary incontinence
Vaginal discharge (from infection etc)
High amniotic leak
Labour (if followed by regular contractions)
Use this to ask questions in a history

Question 14

A patient at 35 weeks gestation presents to you after experiencing a sudden gush of fluid. Give 5 methods to confirm this

Answer 14

Pooling of fluid in the posterior fornix
Amnisure
Vaginal swap pH (nitrazine stick) turns to blue
Microscopy (showing ferning)
Non-diagnostic but US finding reduced amniotic fluid (only indicative)

Question 15

What does Amnisure test for?

Answer 15

Endocervical swab testing for alpha-Macroglobulin 1 in cervical vaginal fluid

Question 16

How would you manage a patient presenting with a gush of fluid (assuming it is a PPROM)
At 31 weeks
At 34 weeks
At 36 weeks

Answer 16

For all you need to Admit the patient, full hx and exam, vitals,
bloods to determine if infection (e.g. CRP),
confirm rupture of membranes using diagnostic methods such as amnisure, Prophylactic Erythromycin 250mg PO QDS.
and check for Group B strep (swab) where if positive => Prophylactic Benzylpenicillin or Clindamycin
Provide Surveillance with CTG tracing
31 weeks: 2x 12mg IM Dexamethasone 12 hours apart + 4g IV bolus MgSO4 followed by 1g/hour maintenance dose.
34 weeks: 2x 12mg IM Dexamethasone 12 hours apart
36: Allow for delivery (C-section or natural). No role for steroids or MgSO4.

For all cases, transfer to tertiary center if cannot be facilitated. Thats where tocolytics can be used.

Question 17

Give your full management plan of a patient presenting with a gush of fluid at 30 weeks. This occurred 28 hours ago. Maternal pyrexia is present

Answer 17

This is a case of prolonged premature rupture of membranes >24 hours
1) Admit the patient, full hx and exam, vitals,
bloods to determine if infection (e.g. CRP),
2) confirm rupture of membranes using diagnostic methods such as amnisure,
3) and check for Group B strep (swab) where if positive => Prophylactic Benzylpenicillin or Clindamycin
4) Foetal monitoring with continuous CTG tracing
5) 2x 12mg IM Dexamethasone 12 hours apart as <34+6 weeks
6) 4g IV bolus MgSO4 followed by 1g/hour maintenance dose
7) There is evidence of maternal pyrexia, Erythromycin 250mg QDS x10 days is recommended

Question 18

What is the major risk of maternal pyrexia in pregnancy?

Answer 18

Chorioamnionitis

Question 19

For MCQ. How do you treat chorioamnionitis

Answer 19

Stat dose of Azithromycin 1g PO, then IV 1g amoxicillin for 48 hours before switching to PO 500mg TDS for 5 days

Question 20

Patients with PPROM are considered high risk especially due to risk of infection.
Give 3 maternal and 3 foetal signs of infection

Answer 20

Maternal:
Foul-smelling vaginal fluid
Contractions/preterm labour
Uterine tenderness
Fever, tachycardia, CRP, increased WCC.

Foetal:
Tachycardia (>160)
Reduced variability on CTG
Alteration in BPP (reduced gross movements, breathing movements, tone, and amniotic fluid volume)

Question 21

What is the effect of steroid administration on WCC

Answer 21

It raises WCC => if concerned of infection check for CRP and pyrexia to confirm

Question 22

When should you deliver in PPROM?

Answer 22

All cases should be delivered by 37 weeks. 34-36 weeks with minor suspicion of infection or compromise. If viable and evidence of foetal compromise => delivery immediately via C-section.

Question 23

What would the consequences of prolonged premature rupture of membranes? (4)

Answer 23

1) Intrauterine infection
2) Placental abruption
3) Cord compression
4) Fetal demise

Question 24

What is the difference between preterm labour and preterm premature rupture of membranes?

Answer 24

in PPROM, rupture of membranes occurs with or without the presence of contractions. In preterm labour, although it can occur with rupture of membranes, is defined by the onset of regular and frequent contractions <37 weeks