Pre-Term Labour and PROM Flashcards
Define preterm labour?
Labour between 24 and 37 weeks.
Before 24 weeks foetus cannot survive so is classed as a miscarriage
How common is preterm labour and what is its associated perinatal mortality?
8% of pregnancies with a 20% rate of perinatal mortality
What are the causes of pre-term labor? (think of a castle)
Castle analogy
Uterus = castle Cervix = castle wall
The wall can be breeched if there are:
- Too many defenders (overcrowding)
AKA multiple pregnancies, excess liquor or polyhdraminos - The defenders jump out
AKA the fetal survival response, spontaneous preterm labor is more likely if the foetus is at risk (pre-eclampsia, IUGR, infection) - The castle design is poor
AKA uterine abnormalities (fibroids, congenital abnormalities) - The wall is weak
AKA cervical incompetency/short cervix (painless cervical dilation pre term)
5. Enemy destroys the wall AKA infection (implicated in 60% of preterm births and often subclincal)
- Enemy surrounds the wall
Urinary infection
What methods can be used to prevent pre-term labour?
Too many defenders:
Fetal reduction of high order multiple pregnancies
NSAIDs to try and reduce fetal UO to reduce polyhraminos (risk of closure of DA)
The defenders jump out:
Management of maternal disease
Weak wall: If short cervix regular transvaginal US Cervical cerclage (insertion of one or more sutures in the cervix)
Infection:
Abx treatment of infection. Note metronidazole can increase the risk of pre-term labour indicating some bactria are beneficial therefore only treat when necessary
How might pre-term labour present?
Painful contractions (abdominal pain)
Ruptured membranes
APH
Note: cervical incompetence is silent
How can you try and prolong labour?
Tocolysis (toco=contraction lysis= to breakdown)
Meds which can be used are:
Nifedipine (Ca channel blocker)
OR
Atosiban (oxytocin receptor antagonist)
Only to be used for 24hrs max
What are the contraindications to trying to prolong labour?
Intrauterine infection
Fetal distress
Vaginal bleeding
Fetal death
PPROM is a relative contraindication
What is the management of a mother in pre-term labour?
If less than 34 weeks: steroids for fetal lung maturation and tocolysis
If greater than 34 weeks:
- Abx only if in informed labour
- Caesarean for usual indications (fetal distress, breech etc)
Always inform neonatology
What is PROM?
Premature rupture of membranes aka rupture of he amniotic sac before labour has started.
If before the 37 weeks =Preterm Premature Rupture of Membranes (PPROM)
How common is PROM?
10% of pregnancies
80% of these will start labour within 24hrs
How is PROM diagnosed?
A history of a gush of fluid or constant trickle
Fluid turns nitazine paper (litmus paper) blue
Vaginal fluid should crystalise as it drys (ferning)
How should PPROM be investigated?
Checking for infection as increases incidence of PPROM
- Urinalysis
- High vaginal swabs for STI’s
- Vaginal test for BV or Trichomoanas
- Test for Group B strep
FBC and CRP if ?chorioamnionitis
CTG to check fetal well being
How should PPROM be managed in a women less than 32 weeks gestation?
Expectant management:
Admit
Check for infection and treat with abx
Restrict activity
Regular fetal monitoring
USS every 3 weeks
Steroids to aid lung maturation
Broad spectrum antibiotics as PPROM predisposes to infection
How should PPROM be managed in a women 32-34 weeks gestation?
Consider abx to prolong latency*
Consider steroids
*time between PROM and delivery
How should PPROM be managed in a women greater than 34 weeks gestation?
Induce labour as risk of infection outweighs that of prematurity.
Give antibiotics if membranes are ruptured for 18hrs or more.
