Premature labour (Complete) Flashcards
Define preterm labour
Delivery of baby before 37 weeks gestations
But after 20 weeks gestation
What percentage of overall births are pre-term?
10%
What are underlying risk factors for premature labour?
Overstretching of uterus:
- Previous pregnancies
- Polyhdraminos
Uterine/cervical abnormalities:
- Uterine fibroids
- Uterine distortion
- Cervical weakness/ short cervix
- Previous uterine/cervical surgery
Foetal factors:
- IUGR
- Pre-eclampsia
- Placental abruption
Infections:
- Chorioamnionitis
- Maternal/neonatal sepsis
- Bacterial vaginosis
- Trichomoniasis
- Group B streptococcus
- STDs
- Recurrent UTIs
Maternal co-morbidities:
- Diabetes
- Hypertension
- Renal failure
- Thyroid disease
What are the main clinical features of premature labour?
Regular uterine contractions
Cervical effacement or dilation
Rupture of membranes before onset of contractions
What differentials should be considered alongside premature labour?
Braxton Hicks contractions
UTI
Placental abruption
Uterine rupture
What investigations should be done if premature labour is suspected?
Bedside:
Speculum examination
- Check for cervical dilation
- Check for pooling of fluid, suggestive of membrane rupture
Insulin-like growth factor protein 1 (IGFP-1) OR alpha microglobulin-1 test:
- Confirm ROM if pooling not found on speculum examination
Foetal fibronectin test:
- Done if membrane intact. Raised levels indicate high risk of labour.
Urine dipstick/urinalysis
- Check for underlying UTI
CTG
- Check foetal statis
Bloods:
FBC: Check for infection
CRP: Check for infection
Imaging:
TV USS: Measure cervical length
When is IGFP-1 or alpha microglobulin-1 testing considered?
To confirm PROM If no obvious evidence of pooling found on speculum examination
Raised levels indicate increase likelihood of pre-term labour
When is foetal fibronectin testing considered?
Considered in patients confirmed to have intact membranes to determine whether they are at high risk of going into labour within 48 hours
N.B. Should always swab first before doing digital examination to reduce risk of false positives
What investigation findings are indicative of premature labour?
Cervical dilation on speculum examination
Elevated foetal fibronectin
Elevated IGFP-1 or alpha microglobulin-1 (If PROM)
Shortened cervix (<2cm): Suggestive of incoming premature labour in patients with closed cervix
What preventative measures are taken for women at high-risk of preterm labour?
Vaginal progesterone
OR
Cervical cerclage (stitching of cervic)
What is the management plan for patients undergoing premature labour?
Conservative:
Continous monitoring for signs of labour or infection
Medicine:
Dexamethasone or betamethasone
- To promote foetal lung maturation in those <34 gestation
Tocolysis: Nifedipine (first-line)
- To delay labour to enable time for corticosteroids to take effect
- CONTRAINDICTED in patients with PROM
Magensium sulfate
- To promote brain development for foeutus if <30 weeks gestation and labour imminent
IV ABx: Penicillin (first-line)
- Consider if high-risk or evidence of infection
Surgical:
Emergency cervical cerclage
- If gestation 16-28 weeks with cervical dilatiion but unruptured membranes
What is the purpose of giving corticosteroids such as dexamethasone/betamethasone in preterm labour?
Helps to promote lung maturation for foetuses <34 weeks gestation
What is the purpose of giving tocolytics?
To delay labour to enable time for corticosteroids to work
What tocolytic is given first line in management of premature labour?
Nifedipine
Tocolytics are contraindicted in which cases?
Premature rupture of membranes
Abnormal cardiotocograph
IUGR o placental insufficiency
Chorioamnionitis
Cervical dilation > 4cm
Maternal factors
- Pre-eclampsia
- Haemodynamic instability
- Ante-partum haemorrhage
What is the purpose of giving magnesium sulfate?
Promote brain development in foetuses <30 weeks gestation
When is IV penicillin considered in patients underoing premature labour?
If evidence or high-risk of group B infection (e.g. group B in previous pregnancy or maternal fever)
What surgical options can be considered for premature labour?
Cervical clerage
Consider if 16-28 gestation and cervical dilation to try and save pregnancy
What is the indication for cervical cerclage?
16-28 gestation and cervical dilation
Cervical cerclage is contraindicted in which cases?
Infection
Bleeding
Uterine contractions
What complications can occur secondary to premature labour?
Neonatal respiratory distress syndrome
NEC
Intraventricular haemorrhage
Periventricular leukamalacia (PVL): Ischaemic damage of white matter sorrounding ventricles, leading to cerebral palsy
How can Braxton Hicks contractions (‘false labour’) be differentiated from premature labour?
Painless like premature labour however:
Contractions are irregular versus continous
No cervical dilation or effacement
How can placental abruption be differentiated from premature labour?
Severe abdominal pain
Vaginal bleeding (can be concealed)
Hard woody uterus
Decreased foetal contractions
How can uterine rupture be differentiated from premature labour?
Severe and sudden onset (‘Catastrophic’)
Contractions and pain can stop suddenly after complete rupture
Foetal distress
Previous C-section
How can UTI be differentiated from premature labour?
Can be a cause of premature labour
Suspect if signs of increased urinary frequency, dysuria ect
