Prematurity, labour and birth Flashcards
True labour is defined as…
Rhythmic regular and increasing contractions with pain and cervical dilation.
List the components of the Bishop score
Dilation Length Consistency Position Station
Indications for induction of labour
Maternal:
- GDM
- PET
- PROM, PPROM
- maternal request
Foetal:
- IUGR/SGA
- dec foetal movements
- post-term (>42wks)
- intrauterine foetal death
Contraindications for IOL
Placenta praevia Vasa praevia Transverse lie Cord prolapse Active maternal genital herpes Relative CI: VBAC
Methods of IOL
- Membrane sweep
- Cervical ripening - prostins (prostaglandin gel/pessary) or balloon (Cooks) catheter
- ARM - only if Bishop score >7. +/- syntocinon
- Syntocinon (oxytocin)
First stage of labour - Definition and phases
From onset of labour to 10cm dilated.
Latent phase:
- Irregular contractions
- Until 4-6cm dilated and fully effaced.
- <1cm/hr dilation
- manage at home
Active phase:
- regular contractions
- 6cm until full dilation
- > 1cm/hr
- admit, analgesia, foetal monitoring
Second stage of labour - duration and definition
Primi: 2 hrs
Multi: 1 hr
From 10cm dilated until delivery of baby
3rd stage of labour definition and duration
Duration <30mins. Avg 6 mins.
From the time the baby is born until the delivery of the placenta
What is active management of the 3rd stage of labour
Oxytocin
Delay clamping of the cord (reduced neonatal anaemia)
Controlled cord traction with uterine stabilisation (prevents uterine inversion)
NB: Oxytocin + controlled cord traction halves the rates of PPH.
4th stage of labour: definition and what to look out for
Defined as the 6hr post-delivery period.
Watch out for PPH, post-partum eclampsia and check the tone of the uterus.
Features of Braxton Hick’s contractions
Common in 2nd and 3rd trimester.
Physiological - helps with foetal positioning.
Irregular, uncoordinated contractions of moderate intensity.
No cervical changes.
Stops with rest, walking or position changes.,
Frequency of contractions in the 2nd stage of labour
4 in 10mins
Indications for assisted delivery
Prolonged 2nd stage of labour (>2hrs in primi, >1hr in multi and add an hour if epidural).
Breech presentation
Non-reassuring foetal HR
Maternal fatigue
Forcep delivery - advantages and complications
Advantages:
- does not require maternal effort
- scalp injuries less common than vacuum
- lower rate of failure than vacuum
Complications: Maternal - genital lacerations - perineal hematoma - urinary tract and sphincter injury - need epidural and episiotomy
Foetal:
- head or soft tissue trauma
- facial nerve palsy
- ICH
- skull #
Vacuum extractor delivery - advantages, disadvantages and complications
Advantages:
- decreases incidence of 3rd and 4th deg tears
- no analgesia required
- less space required
Disadvantages:
- required maternal pushing
- higher rate of failure
Complications:
Maternal
- genital hematoma/lacerations
Foetal
- cephalohaematoma, scalp lac
- ICH
Contraindications for VBAC
Classical CS scar Hx uterine rupture Multiple pregnancy Placenta praevia Transverse lie
Indications for VBAC
Maternal request if:
- 1 x prev LSCS
- singleton pregnancy
- cephalic presentation
Main risk with VBAC
Uterine rupture (1 in 200) --> maternal haemorrhage, hysterectomy and death. Baby: HIE, death. Placental abruption (1 in 100)
NB: oxytocin augmentation doubles risk of rupture to 1 in 100
Prostaglandins increase it to 1 in 50.
Management principles of VBAC
Avoid induction (balloon and ARM are the least risky).
Continuous CTG.
Analgesia.
No more than 3 hrs of no progress.
Definition of term SROM
SROM at >37wks without any signs or symptoms of labour
Management of term SROM
Expectant VS IOL.
Expectant:
Criteria = All healthy women (GBS -ve, no signs of infection, clear liquor, normral CTG).
Watch and wait.
If no labour after 18hrs –> abx (clindamycin or ben pen)
If no labour after 24hrs –> IOL with oxytocin.
IOL:
Done immediately if GBS +ve woman.
Use oxytocin.
PROM and PPROM - definition
PROM = Prelabour ROM at or beyond 37 wks gestation with failure to establish labour 4 hrs after ROM.
PPROM = ROM at <37wks.
What is pre-viable PPROM
PPROM at <23wks
No resus due to pulmonary hypoplasia ad inevitable foetal demise.
Risk factors for PPROM and PROM
Chorioamnionitis UTI APH Polyhydramnios Smoker Multiple pregnancy Amniocentesis External cephalic version
Investigations for PPROM and PROM
Confirm it’s amniotic fluid:
- Amnisure (alpha microglobulin protein)
- pH stick (Nitrazine)
- Actimprom
Low vaginal swab for GBS
Urinalysis and urine MCS
Pelvic US (liquor volume, cervical length)
PPROM and PROM management
Admit to ward (50% will deliver within 24 hrs) Maternal obs Foetal obs Steroids Abx: erythromycin for chorio prevention Timing of delivery -Term: IOL or expectant - Preterm: safe to wait until 37 wks (weekly ANC review, monitor temp at home) -Sepsis: deliver immediately
Complications of PPROM and PROM
Maternal:
- cord prolapse
- cord compression
- maternal infection
- chorioamnionitis
Foetal:
- sepsis
- death
- lung hypoplasia
- foetal hypoxia
- periventricular leukomalacia –> cerebral palsy
Define pre-term labour
Onset of regular and painful contractions with effacement and dilation of the cervix at between 20-37wks gestation.
Survival rates of preterm birth
After 23wks –> 20% survival
After 31wks –> 90% survival
Aetiology of preterm birth
Most common: PROM, chorioamnionitis, UTI.
Stress (mental or physical)
- maternal stress –> cortisol –> trigger of labour
- Foetal stress (hypoxia)
- intercurrent illness
Infection
- chorioamnionitis
- UTI
- BV
Placental abruption
- uterus will contract to clamp off the bleeding BVs
Uterine/cervical abnormality
- uterine distention in multiple pregnancy or polyhydramnios (tricks uterus into thinking that the pregnancy is further along than it is)
- cervical insufficiency
Risk factors for preterm labour
Previous preterm delivery (biggest Rx Fx) Smoking and drug use Multiple pregnancy Polyhydramnios PPROM PET Previous cervical surgery UTI, genital tract infections Extremes of maternal age
Diagnosis of preterm labour
Sterile speculum exam:
- pooling of amniotic fluid
- swab post fornix for foetal fibronectin (FFN is the glue that holds the amnion to the decida. Disruption of interface –> release of FFN into vaginal secretions)
TVUS (measure cervical length)
Mid-stream urine MCS
High vaginal swab MCS
Management of a woman in preterm labour
Corticosteroids (betamethasone or dexamethasone) if <34wks
Tocolysis
- delays births to give the steroids time to work
- 1: nifedipine (SM relaxant)
- 2: beta agonists (salbutamol)
- 3: Prostaglandin synthase inhibitors (indomethacin)
Magnesium sulfate
- if birth is imminent at <30 wks
- neuroprotective against cerebral palsy
ABX if PPROM or infection
Management of asymptomatic women at high risk of preterm labour
Screen for genitourinary infections and treat them (UTI, BV).
Smoking cessation
Monitor cervical length from 16wks
Vaginal progesterone or cervical cerclage.
Risks of preterm birth
Child:
- neonatal death
- cerebral palsy
- hearing impairment
- visual impairment (retinopathy of prematurity, hypermetropia, myopia)
- cognitive impairment, ADHD, dyslexia
- chronic lung disease
- inc risk non-communicable disease (asthma)
Mother:
- recurrent PTL
- IHD, stroke
WHO recommendations for improving outcomes of preterm birth
4-1-4
Intrapartum - 4 drugs:
- Tocolysis
- Steroids from 24-34wks
- Magnesium sulfate if <32 wks
- Erythromycin if PPROM or infection
Delivery:
6. Routine CS not recommended
Post-partum - breathing support:
- Kangaroo care (skin on skin)
- CPAP for respiratory distress syndrome
- Surfactant replacement for RDS
- O2 therapy starting at 30%
Indications for caesarean section
Maternal:
- elective
- failure to progress in 2nd stage labour
- placenta praevia
- repeat CS
- APH
Foetal:
- Non-reassuring CTG
- malpresentation
- cord prolapse
- multiple pregnancy
