Preterm labour Flashcards
What is the definition of preterm labour?
Delivery before 37 weeks
Name 5 reasons besides spontaneous preterm labour for labour before 34 weeks
PROM/infection (chorioamnionitis) Multiple pregnancy APH HT/pre-eclampsia Foetal growth restriction
Name 5 ways to prevent preterm labour
Lifestyle modification - education, bed rest Cervical cerclage (stitch) Prophylactic tocolysis Uterine activity monitoring Optimise maternal condition Control vaginal infection
Name ways of predicting onset of preterm labour
Uterine activity monitoring
Serial cervical assessment (length - short length = more chance of cervical incompetance)
Cervicovaginal microbiology/biochemistry - foetal fibronectin
How is foetal fibronectin useful in predicting preterm labour? How do you test for it?
Foetal fibronectin released during subclinical uterine contractions. Swab posterior fornix for fibronectin - high negative predictive value (no fibronectin = low chance of delivery)
Name the 4 classes of tocolytics. Which is the most widely used and why?
Calcium antagonist (Nifedipine) - most widely used (fewest SE)
Beta-adrenergics (Salbutamol, ritodrine, Terbutaline)
MgSO4
PGE2 inhibitors (Indomethacin)
Name a maternal, foetal and placental contraindication to beta-adrenergic tocolysis
Maternal - cardiac disease, PE, HT, hyperthyroidism, DM, PROM, sepsis
Placental - placental abruption, bleeding praevia
Foetal - gestation 32 weeks, growth restriction, FDIU, lethal abnormality, advanced labour
What is the most important thing to remember when considering giving a tocolytic? Give three reasons you might use tocolysis
Only give tocolytic if it will improve outcome, not just to delay onset of labour
Might use tocolysis to allow transfer to suitable facility, cortisol administration, or MgSO4 administration
Go through the role of endogenous steroids in normal labour.
Before delivery, foetal pituitary releases ACTH and cortisol to stimulate prostaglandin and oestrogen release from placenta. This induces labour, as well as lung maturation.
What are two benefits of giving exogenous steroids in premature labour? To which women and when should you give it?
Reduce incidence of respiratory distress (from lung maturation) and necrotising enterocolitis.
Give to women under 34 weeks, less than 1 week before delivery
What disease does MgSO4 reduce the incidence of? To which women and when should you give it?
Cerebral palsy. Give to women under 30 weeks, less than 4 days before delivery
What is the difference between premature rupture of membranes and prelabour rupture of membranes?
Prelabour rupture of membranes = ROM in term baby, before labour commences
Premature ROM = ROM in preterm baby
Name 5 causes of PROM
Idiopathic/unknown APH Congenital membrane weakness Uterine anomaly Genital tract infection
Name 4 signs/symptoms of PROM
Small-for-dates uterus (loss of liquor)
Vaginal fluid loss
Odour
Alkaline pH
What is the main Ddx of PROM? What is a test that can be done to distinguish this from PROM?
Urinary incontinence. Can do pyridium test on vaginal discharge - if positive = urine
