Preterm labour NICE guideline

November 2015

Aboubakr Elnashar Benha university, Egypt

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Definitions

I. Prevention

II. Diagnosis

III. Treatment

1. Tocolysis

2. Corticosteroids

3. Mg sulfate

4. Foetal monitoring

5. Mode of birth

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DEFINITIONS

Symptoms of PTL

Before 37+0 w

symptoms that might be indicative of PTL(such

as abdominal pain), but

no clinical assessment (including speculum or

digital vaginal examination) has taken place.

Suspected PTL

symptoms of PTL and

clinical assessment (including a speculum or

digital vaginal examination) that confirms the

possibility of PTL but rules out established

labour.

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Diagnosed PTL

suspected PTL and

positive diagnostic test for PTL.

Established PTL

Progressive cervical dilatation from 4 cm with

regular contractions.

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Rescue' cervical cerclage

Cervical cerclage performed as an emergency

procedure in a woman with premature cervical

dilatation and often with exposed fetal

membranes.

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I. PREVENTION

Offer a choice of

prophylactic vaginal progesterone OR

prophylactic cervical cerclage

history of spontaneous PTB or mid-trimester loss

between 16+0 and 34+0 w and

TVS carried out between 16+0 and 24+0 w:

cervical length ≤25 mm. Discuss the benefits and risks of prophylactic progesterone and cervical cerclage with the woman and take her preferences into account.

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Offer prophylactic vaginal progesterone

No history of SPTB or mid-trimester loss in

whom TVS carried out between 16+0 and 24+0

w: cervical length ≤25 mm.

Consider prophylactic cervical cerclage

TVS carried out between 16+0 and 24+0 w:

cervical length of less than 25 mm and who have

either:

had P-PROM in a previous pregnancy or

history of cervical trauma.

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Rescue' cervical cerclage

Contraindications:

signs of infection

active vaginal bleeding

uterine contractions.

Indications:

between 16+0 and 27+6 w

with a dilated cervix and exposed,

unruptured fetal membranes Take into account

gestational age (being aware that the benefits are likely to be greater for earlier gestations) extent of cervical dilatation discuss with a consultant obstetrician and consultant paediatrician.

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Explain to women:

Risks of the procedure

Aims to delay the birth: increase the likelihood

of the baby surviving and of reducing serious

neonatal morbidity.

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II. Diagnosis

Clinical assessment

History taking

Observations

Speculum examination (followed by a digital vaginal examination if the extent

of cervical dilatation cannot be assessed).

Measuring cervical length using TVS most accurate way to diagnose PTL when used alone

for women over 30 w.

Fibronectin: useful if cervical length measurement not available or

not acceptable

not as good a diagnostic tool as cervical length.

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Suspected PTL and 29+6 w or less:

tt for PTL

Suspected PTL and 30+0 w or more:

TVS measurement of cervical length as a diagnostic

test to determine likelihood of birth within 48 h:

if cervical length is more than 15 mm unlikely that she is in PTL

think about alternative diagnoses

discuss with her the benefits and risks of going home

compared with continued monitoring and tt in hospital

advise her that if she does decide to go home, she

should return if symptoms suggestive of PTL persist or

recur

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if cervical length is 15 mm or less

view the woman as being in diagnosed PTL:

offer tt

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fetal fibronectin testing

diagnostic test to determine likelihood of birth

within 48 h

for

women who are 30+0 w or more

TVS measurement of cervical length is

indicated but is not available or not acceptable

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if fetal fibronectin testing is negative (concentration

50 ng/ml or less):

unlikely that she is in PTL

think about alternative diagnoses

discuss with her the benefits and risks of going

home compared with continued monitoring and tt

in hospital

advise her that if she does decide to go home,

she should return if symptoms suggestive of

preterm labour persist or recur

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if fetal fibronectin testing is positive (concentration

more than 50 ng/ml)

diagnosed PTL: offer tt

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Suspected PTL

30+0 w or more

does not have TVS measurement of cervical length

or fetal fibronectin testing to exclude preterm labour:

offer treatment consistent with her being in

diagnosed PTL

Do not use TVS measurement of cervical length

and fetal fibronectin testing in combination to

diagnose PTL

Ultrasound scans should be performed by

healthcare professionals with training in, and

experience of, transvaginal ultrasound

measurement of cervical length.

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III. TREATMENT

1. Tocolysis

Calcium blockers

most clinical and cost-effective tocolytic

Oxytocin receptor blockers

effective for some other outcomes

not the most effective option overall.

Prostaglandin inhibitors

produce a protective effect for delaying birth

by more than 48 hours.

long-term consequences of tocolytics for both

babies and their mothers:

limited data

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Take into account :

whether the woman is in suspected or

diagnosed PTL

other clinical features:

bleeding or infection which may suggest that

stopping labour is contraindicated

gestational age at presentation

likely benefit of maternal corticosteroids

availability of neonatal care (need for transfer

to another unit)

preference of the woman.

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Consider Nifedipine

between 24+0 and 25+6 w

intact membranes

suspected PTL

Offer nifedipine:

26+0 and 33+6 w

intact membranes

suspected or diagnosed PTL

If nifedipine is contraindicated:

oxytocin receptor antagonists for tocolysis.

Do not offer betamimetics for tocolysis.

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2. Corticosteroids

Discuss with woman:

23+0 and 23+6 w

suspected or established PTL

having a planned preterm birth or

have PPROM

Consider

between 24+0 and 25+6 w

in suspected or established PTL

having a planned preterm birth or

have P-PROM.

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Offer

between 26+0 and 33+6 w

in suspected, diagnosed or established PTL

having a planned preterm birth or

have P-PROM.

Consider

between 34+0 and 35+6 w

in suspected, diagnosed or established PTL

having a planned preterm birth or

have P-PROM.

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Do not routinely offer repeat courses of maternal

corticosteroids, but take into account:

the interval since the end of last course

gestational age

the likelihood of birth within 48 hs.

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3. Mg sulfate

for neuroprotection of the baby

between 24+0 and 29+6 w who are:

in established PTLor

having a planned preterm birth within 24 h.

Consider

30+0 and 33+6 w who are:

in established PTL or

having a planned preterm birth within 24 h.

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4 g IV bolus over 15 min, followed by IV infusion

of 1 g/h until the birth or for 24 h (whichever is

sooner).

Monitor

clinical signs of magnesium toxicity/4 h by

recording pulse, blood pressure, respiratory rate

and deep tendon (for example, patellar)

reflexes.

If a woman has or develops oliguria or other

signs of renal failure:

monitor more frequently for magnesium toxicity

think about reducing the dose of magnesium

sulfate.

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4. Foetal monitoring

Explain to the woman

different fetal monitoring options

Normal CTG

Reassuring

indicates that the baby is coping well with

labour,

Abnormal

does not necessarily indicate that fetal

hypoxia or acidosis is present.

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absence of evidence that using CTG improves

the outcomes of PTL for the woman or the baby

compared with intermittent auscultation.

Offer women in established PTL but with no other

risk factors a choice of FHR monitoring using

either:

CTG using external ultrasound or

intermittent auscultation.

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CTG and intermittent auscultation

Discuss with women in suspected, diagnosed

or established PTL:

the purpose of fetal monitoring and what it

involves

the clinical decisions it informs at different

gestational ages

if appropriate, the option not to monitor FHR

(for example, at the threshold of viability).

Involve a senior obstetrician

in discussions about whether and how to

monitor the FHR for women who are between

23+0 and 25+6 w

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Fetal scalp electrode

Do not use a fetal scalp electrode for FHR

monitoring if the woman is less than 34+0 w

unless all of the following apply:

it is not possible to monitor FHR using either

external CTG

or intermittent auscultation

it has been discussed with a senior obstetrician

the benefits are likely to outweigh the potential

risks the alternatives (immediate birth,

intermittent ultrasound and no monitoring) have

been discussed with the woman and are

unacceptable to her.

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Discuss with the woman the possible use of a

fetal scalp electrode between 34+0 and 36+6 wee

if it is not possible to monitor the fetal heart rate

using either external cardiotocography or

intermittent auscultation.

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Fetal blood sampling

Do not carry out fetal blood sampling if the

woman is less than 34+0 w.

Discuss with the woman the possible use of

fetal blood sampling between 34+0 and 36+6 w

if the benefits are likely to outweigh the

potential risks.

When offering fetal blood sampling, discuss

this with the woman and advise her that if a

blood sample cannot be obtained CS is likely.

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5. Mode of birth

Discuss the general benefits and risks of CS

and vaginal birth with women in suspected,

diagnosed or established PTL and women with

P-PROM

Explain to women in suspected, diagnosed or

established PTL and women with P-PROM

about the benefits and risks of CS that are

specific to gestational age.

highlight the difficulties associated with

performing CS for PTL, especially the

increased likelihood of a vertical uterine incision

and the implications of this for future

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Explain to women in suspected, diagnosed or

established preterm labour that there are no

known benefits or harms for the baby from CS, but

the evidence is very limited.

Consider CS for women presenting in

suspected, diagnosed or

established PTL between 26+0 and 36+6 w with

breech presentation.

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Timing of cord clamping for preterm babies (born

vaginally or by CS

If a preterm baby needs to be moved away

from the mother for resuscitation, or

there is significant maternal bleeding:

consider milking the cord and

clamp the cord as soon as possible.

if the mother and baby are stable.

Wait at least 30 seconds, but no longer than 3

minutes, before clamping the cord

Position the baby at or below the level of the

placenta before clamping the cord.

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