Still Birth The CTG and Liquor Flashcards
What is the definition of a still birth
Born dead after 24 weeks (but were still alive at 24 weeks). After a few hours of foetal death, the skin begins to peel and the baby is described as macerated rather than fresh still birth.
What are the causes of still birth?
Unknown Placental cause Ante or intra partum haemorrhage Major congenital abnormality Infection Hypertension in pregnancy Maternal disease IUGR Mechanical – cord prolapse or knot
What are the clinical features used to diagnose a still birth?
Reduced foetal movement
No foetal heart sound on auscultation or CTG – absolute diagnosis from US
What is the intital management of a confirmed still birth?
Give Anti-D if mother Rhesus negative and perform Kleihaurer
If large FMH then check Kleihaurer again in 4hours to confirm removal of foetal blood cells
Labour occurs naturally in 80% within 2 weeks
Check maternal: Temp, BP, urine and blood for clotting screen
Immediate delivery if: pre-eclamptic, abruption, sepsis, coagulopathy or membrane rupture
How should the baby be delivered after a still birth?
If safe mother may go home to reflect, prepare and collect things and make arrangements.
If not induced in 48hours check for coagulopathy every 2 weeks
Labour induced using Mifepristone and prostaglandins added vaginally
Oxytocin augmentation may be required later
Ensure good pain relief
Delivery away from sounds of babies
What should be done after delivery to help the mother’s grieving process?
Once delivered give to mother wrapped as usual if she wishes
Take photograph, lock of hair and palm prints for mother
Funeral may help grieving process
How does a CTG work?
Cardiotocography (CTG) records pressure changes in the uterus using internal or external pressure transducers as well as the foetal heart rate. The normal foetal heart rate varies between 100-160/min.
How does each contraction affect the foetus?
Every contraction in labour puts stress on the foetus due to restriction of placental blood supply. The ability to withstand this is called the foetal reserve. If the foetal reserve isn’t enough it may start to decompensate.
What are the maternal indications for CTG
Previous CS Cardiac problems Pre-eclampsia Gestation over 42 weeks PROM >24hours IOL Diabetes Antepartum haemorrhage
What are the foetal indications for CTG
IUGR Prematurity Oligohydramnios Abnormal doppler Multiple pregnancy Meconium stained liquor Breech presentation
What intrapartum risks would require a CTG?
Oxytocin augmentation Epidural analgesia Intrapartum vaginal bleeding Pyrexia >37.5 Fresh meconium staining of liquor Prolonged labour
What accronymn is used for interpretation of CTGs?
DR C BRAVADO: Determine Risk, Contractions (how many in 10), BRA (Baseline rate), Variability, Accelerations, Decelerations and Overall:
Describe a reassuring baseline, variability, deceleration and accelerations of a CTG
Baseline 100-160
> 5 variability
No or early decelerations
Accelerations present
All 4 must be reassuring to indicate a reassuring CTG
Describe a non-reassuring baseline, variability, deceleration and accelerations of a CTG
Baseline 161-180
<5 variability for 1-1.5hrs
Variable decelerations for >50% of contraction for >90min or taking >60s to recover for >30mins
No Accelerations
1 non reassuring = non-reassuring
Describe an abnormal baseline, variability, deceleration and accelerations of a CTG
Baseline <100 or >180
<5 variability for >90min
Late decelerations in >50% of contractions for >30 mins or single long deceleration >3min
No accelerations
2 non reassuring or one abnormal = abnormal
Define and give normal ranges for baseline rate, baseline variability, accelerations and deceleration
Baseline rate – average of foetal heart rate
Baseline variability – degree to which baseline varies. 5-25 bpm = normal
>25 variability = saltatory variability, <5 variability = reduced variability
Accelerations = transient rise of baseline rate by 15 or more lasting 15seconds or more
Decelerations = transient drop in baseline by 15 or more lasting 15 seconds or more
What are the common causes of baseline bradycardia?
Increased foetal vagal tone, maternal beta-blocker use
What are the common causes of baseline tachycardia?
Maternal pyrexia, chorioamnionitis, hypoxia, prematurity
What are the common causes of loss of baseline variability?
The most common explanation for short episodes (< 40 minutes) of decreased variability on CTG is that the foetus is asleep. However, if the decreased variability lasts for more than 40 minutes, start to worry. Other causes of decreased variability in foetal heart rate on CTG are due to maternal drugs (such as benzodiazepines, opioids or methyldopa - not paracetamol), foetal acidosis (usually due to hypoxia), prematurity (< 28 weeks), foetal tachycardia (>140 bpm) and congenital heart abnormalities.
What are the common causes of early decelerations?
Deceleration of the heart rate which commences with the onset of a contraction and returns to normal on completion of the contraction
Usually an innocuous feature and indicates head compression
What are the common causes of late decelerations?
Deceleration of the heart rate which lags the onset of a contraction and does not returns to normal until after 30 seconds following the end of the contraction
Indicates foetal distress e.g. asphyxia or placental insufficiency
What are the common causes of variable decelerations?
Independent of contractions
May indicate cord compression
Does a women’s position have an impact on the CTG tracing?
The woman’s position can often have a large impact on CTG tracing so attempt to move the women and see if this causes the CTG to improve. VE, emptying the bladder or bowel, vomiting and topping up of regional analgesia may all also play a part.
Are there any tests we can use to improve specificity of the CTG?
Foetal scalp blood sampling can be used to improve the specificity of CTG in detecting foetal hypoxia. Only undertaken if the trace is pathological and immediate delivery isn’t indicated. If pH less than 7.2 immediate delivery is advised.
What does the presence of meconium before delivery indicate?
If it is found in the liquor (amniotic fluid) then this indicates a foetus that may be in distress, also it could be aspirated. MSAF (meconium stained amniotic fluid) is rare in preterm. It increases in incidence with gestation. Passage of meconium signified maturation of the central nervous system but sometimes hypoxia causes peristalsis and sphincter relaxation.
What is the biggest risk of early meconium release?
Meconium aspiration syndrome
Can happen in utero and causes mechanical blockage of the airways, chemical irritation – pneumonitis and predisposes to secondary bacterial infection.
What are the 3 grades of meconium staining amniotic fluid?
Grade 1 – light staining
Grade 2 – dark green staining of amniotic fluid that is usually opalescent
Grade 3 – thick opaque meconium in scanty amniotic fluid
How should MSAF be managed?
Induction of labour immediately if PROM
Continuous foetal monitoring
Advise delivery in hospital with neonatal facilities
What is amniotic fluid made from?
Amniotic fluid consists of foetal urine and so its volume is dependant on urine production, foetal swallowing and absorption.
When is amniotic fluid at its highest volume and how can it be measured?
Highest volume is usually between 24 and 36 weeks. The volume can be measure via USS by measuring the deepest pools or adding up all 4 quadrant deepest pools.
What is oligohydramnios?
Reduced amniotic fluid volume
What are the common causes of oligohydramnios?
PROM can lead to oligohydramnios and can be related to early delivery/infection
IUGR can cause oligohydramnios and leads to mortality and morbidity
Renal agenesis or other renal problems
Post term gestation
Pre-eclampsia
What complications can occur as a result of oligohydramnios?
Lung hypoplasia if before 22 weeks
Limb abnormalities
Before 22 weeks has a very poor prognosis
How should oligohydramnios be managed?
If PROM is the cause then manage as this
IUGR – manage according to umbilical doppler and CTG
Unknown cause – reconsider possible diagnosis but intervention not required if dopplers are normal.
Refer to foetal medicine if foetal renal tract abnormality.
What is polyhydramnios?
Increase amniotic fluid volume
What causes polyhydramnios?
Increased foetal urine production – maternal diabetes, twin-twin transfusion syndrome (recipient twin) and foetal hydrops.
Foetal swallowing difficulty or inability – GI tract obstruction (duodenal atresia, fistulas), neurological or muscular abnormality (myotonic dystrophy, anencephaly), idiopathic (mild)
What are the complications from polyhydramnios?
Preterm delivery due to uterine stretch
Of the cause e.g. duodenal atresia and trisomy 21
Malpresentation at delivery due to increased room
Maternal discomfort from distension
How should polyhydramnios be investigated?
GTT to exclude maternal diabetes
USS examination of foetus
How should polyhydramnios be managed?
If severe usually indicates foetal abnormality – refer foetal medicine
Amnioreduction via needle or NSAIDs (cause foetal oliguria close supervision needed)
If preterm assess risk of delivery and give steroids
If unstable or transverse lie at term admit and CS
