Labour Medicine Flashcards
What is PPROM? What are some complication and how is it managed?
Premature prelabour rupture of membranes between 24-36+6wks
Occurs in about 2% pregnancies but 40% of preterm deliveries
Complications:
Foetal - prematurity, infection, pulmonary hypoplasia
Maternal - choriomnionitis
Management:
Admission
Regular obs to ensure no choriomnionitis developing
Oral Abx - erythromycin (10 days or until in labour)
Antenatal corticosteroids (Dex)- get baby producing surfactant
Mg sulphate - reduce CP risk
Possible tocolytics to delay labour (if in premature labour)
Deliver at 34wks to reduce foetal and maternal risks
What is chorioamnionitis?
Acute inflammation of foetal amnion and chorion membranes - usually secondary to ascending infection in the context of membrane rupture (though can also occur with membranes intact - mycoplasma infection here is common)
Can affect up to 5% of all pregnancies
Medical emergency
How does chorioamnionitis present?
Uterine tenderness
Rupture of membranes
Foul smelling liquor
Signs of maternal infection:
Tachycardia, pyrexia, leukocytosis
How do you manage chorioamnionitis?
Emergency C-section
IV Abx - Benpen + gent (no standard regimen)
What is post term pregnancy, what are the risks and how is it managed?
Anything over 42wks
Increased risk of:
Reduced placental perfusion
Oligohydraminos
Forceps/C-section
Can be offered induction at 41wks - medically is preferred if no signs of foetal compromise (if present, then C-S)
What is polyhydramnios? What are some risks for developing it?
Increased amniotic fluid around the baby - >24cm (oligo = <5cm)
TORCH infection (need to screen for: toxoplasmosis, rubella, CMV, herpes, (HIV, VZV, ParvoB19)
GDM (need to check BGs, baby growth) (because foetal hyperglycaemia - weeing more - more amniotic fluid)
Tracheo-oesophageal fistula (due to foetal inability to swallow fluid)
What are some risks of polyhydramnios?
Placenta abruption
Malpresentation
Cord prolapse: (malpresentation/SGA/Prematurity/PROM also risks for this)
Cord out first, often in 2nd stage of labour, may/not be palpable, on contact with oxygen - spasms, occludes umbilical blood flow to foetus, foetus becomes hypoxic, decrease in foetal HR that does not resolve; emergency C-S needed
What is a sweep?
Cervical sweep can be performed when the cervix is slightly dilated
Involves running finger around the rim of the cervix - triggers local hormone/prostaglandin release and expedites cervical ripening - may go into full labour within 24hrs
Sweep may not work
What do you do for induction of the cervix is not open at all?
Insert a balloon/Foley catheter into the neck of the cervix and inflate - this triggers the release of local hormones/prostaglandins and expedites labour
Patient may even be allowed to go home - when falls out, cervix has dilated sufficiently that natural labour or other adjuncts may begin to work
What do you give to ripen the cervix? How does this process work?
Vaginal prostaglandins:
One cycle of vaginal PGE2 tablets or gel: one dose, followed by a second dose after 6 hours if labour is not established (up to a maximum of two doses)
OR
One cycle of vaginal PGE2 controlled-release pessary: one dose over 24 hours
E.g. Prostin, propess
Cervical ripening involves the dilation of the opening, the narrowing of the canal and the effacement (coning/retraction) of the superior cervix to create space for the baby’s head to sit in and eventually pass through
Foetuses should be monitored with continuous cardiotocography (CTG) if induced in this way
What do you give to stimulate contractions? How does this work?
Syntocinon - via IVI - not to be started for at least 6 hours after administration of vaginal prostaglandin, dose increased at intervals of at least 30 minutes until a maximum of 3–4 contractions occur every 10 minutes
It is exogenous oxytocin (normally synthesised by hypothalamus and secreted by posterior pituitary)
Contractions can be quite powerful, may need pain relief
What is malpresentation?
Cephalic e.g. head down low in pelvis is the only good presentation
Malpresentation:
Transverse e.g. baby lying perpendicular to mothers spine
Breech e.g. with bum/feet by neck of cervix and head superior
Babies tend to be smaller with less amniotic fluid and less obviously move
What is a scrape?
Also known as a foetal blood sample
Can be obtained once cervix is >3cm
Use for a neonatal blood gas:
If 7.25 = normal
If <7.21 = acidotic secondary to hypoxia - needs proper induction or any form of delivery asap
If between 7.25-7.21 = borderline, repeat in 30mins
Can also use lactate as an indicator of the same
How fast does labour progress?
First 4cm of dilatation can be any time really, sometimes very slow
After 4cm, tend to progress at the rate of c.1/2cm per hr until delivery for nullips and 1cm/hr in multips
Why might a foetus be hypoxic?
Might be squashing the umbilical cord - if placenta is low lying and we know it’s location, we can shift her to lie on the opposite side - might stop baby from pressing on/occluding the cord
Placental insufficiency - from smoking, HTN (or HoTN), cocaine or other drug use, alcohol
Cord prolapse, placenta abruption, true knot in the cord, chorioamnionitis
What is a prolonged labour? What are some reasons for failure to progress in labour?
Labour lasting 20+hrs if primigravid, 14+ if parous
Prolonged latent phase (before 4cm dilated); from the start of the active second stage - c.<3hrs in nulliparous, c. <2hrs in multips
Risks/causes: Slow effacement of the cervix Baby >4.5kg Small birth canal or pelvis Malpresentation Multiple babies Epidural
What do you monitor before and/or during labour? What circumstances do you change to obstetric lead care?
Foetus:
Presentation - anything not cephalic that can’t be changed including cord prolapse
Lie - transverse/oblique
Suspected growth restriction or macrosomia
CTG - Foetal heart rate and relationship to contractions - decelerations especially
Mother:
Temp - >38 on one reading or >37.5 on 2, 1hr apart
HR - >120bpm on 2x occasions 30mins apart
BP - >160/110
Cervical dilation
Urine - 2+ protein
Blood loss
Meconium
Delay in labour
Tears than need suturing antepartum haemorrhage, cord prolapse, PPH, seizure, retained placenta
What are some risk factors for postpartum haemorrhage?
Antenatal: Previous retained placenta or PPH or antepartum haemorrhage Maternal Hb below 85g/L at labour onset BMI >35kg Maternal age >35yrs Grand multiparity of 5+ Existing uterine abnormality Low lying placenta
Labour: Induction Prolonged at any stage OXT use Operative birth or C-section
Mnemonic -
Tone - atonic uterus (over distension - polyhydraminos, macrosomia; prolonged labour)
Trauma - episiotomy, operative birth/c-section
Tissue - retained placenta (placenta accreta)
Theombin - coagulopathies
