Still Birth The CTG and Liquor

Question 1

What is the definition of a still birth

Answer 1

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.

Question 2

What are the causes of still birth?

Answer 2

Unknown 
Placental cause
Ante or intra partum haemorrhage
Major congenital abnormality 
Infection
Hypertension in pregnancy 
Maternal disease 
IUGR 
Mechanical – cord prolapse or knot

Question 3

What are the clinical features used to diagnose a still birth?

Answer 3

Reduced foetal movement

No foetal heart sound on auscultation or CTG – absolute diagnosis from US

Question 4

What is the intital management of a confirmed still birth?

Answer 4

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

Question 5

How should the baby be delivered after a still birth?

Answer 5

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

Question 6

What should be done after delivery to help the mother’s grieving process?

Answer 6

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

Question 7

How does a CTG work?

Answer 7

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.

Question 8

How does each contraction affect the foetus?

Answer 8

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.

Question 9

What are the maternal indications for CTG

Answer 9

Previous CS
Cardiac problems 
Pre-eclampsia
Gestation over 42 weeks 
PROM >24hours 
IOL
Diabetes
Antepartum haemorrhage

Question 10

What are the foetal indications for CTG

Answer 10

IUGR
Prematurity 
Oligohydramnios 
Abnormal doppler
Multiple pregnancy 
Meconium stained liquor 
Breech presentation

Question 11

What intrapartum risks would require a CTG?

Answer 11

Oxytocin augmentation 
Epidural analgesia 
Intrapartum vaginal bleeding 
Pyrexia >37.5 
Fresh meconium staining of liquor 
Prolonged labour

Question 12

What accronymn is used for interpretation of CTGs?

Answer 12

DR C BRAVADO: Determine Risk, Contractions (how many in 10), BRA (Baseline rate), Variability, Accelerations, Decelerations and Overall:

Question 13

Describe a reassuring baseline, variability, deceleration and accelerations of a CTG

Answer 13

Baseline 100-160

> 5 variability

No or early decelerations

Accelerations present

All 4 must be reassuring to indicate a reassuring CTG

Question 14

Describe a non-reassuring baseline, variability, deceleration and accelerations of a CTG

Answer 14

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

Question 15

Describe an abnormal baseline, variability, deceleration and accelerations of a CTG

Answer 15

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

Question 16

Define and give normal ranges for baseline rate, baseline variability, accelerations and deceleration

Answer 16

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

Question 17

What are the common causes of baseline bradycardia?

Answer 17

Increased foetal vagal tone, maternal beta-blocker use

Question 18

What are the common causes of baseline tachycardia?

Answer 18

Maternal pyrexia, chorioamnionitis, hypoxia, prematurity

Question 19

What are the common causes of loss of baseline variability?

Answer 19

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.

Question 20

What are the common causes of early decelerations?

Answer 20

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

Question 21

What are the common causes of late decelerations?

Answer 21

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

Question 22

What are the common causes of variable decelerations?

Answer 22

Independent of contractions

May indicate cord compression

Question 23

Does a women’s position have an impact on the CTG tracing?

Answer 23

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.

Question 24

Are there any tests we can use to improve specificity of the CTG?

Answer 24

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.

Question 25

What does the presence of meconium before delivery indicate?

Answer 25

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.

Question 26

What is the biggest risk of early meconium release?

Answer 26

Meconium aspiration syndrome
Can happen in utero and causes mechanical blockage of the airways, chemical irritation – pneumonitis and predisposes to secondary bacterial infection.

Question 27

What are the 3 grades of meconium staining amniotic fluid?

Answer 27

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

Question 28

How should MSAF be managed?

Answer 28

Induction of labour immediately if PROM
Continuous foetal monitoring
Advise delivery in hospital with neonatal facilities

Question 29

What is amniotic fluid made from?

Answer 29

Amniotic fluid consists of foetal urine and so its volume is dependant on urine production, foetal swallowing and absorption.

Question 30

When is amniotic fluid at its highest volume and how can it be measured?

Answer 30

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.

Question 31

What is oligohydramnios?

Answer 31

Reduced amniotic fluid volume

Question 32

What are the common causes of oligohydramnios?

Answer 32

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

Question 33

What complications can occur as a result of oligohydramnios?

Answer 33

Lung hypoplasia if before 22 weeks
Limb abnormalities
Before 22 weeks has a very poor prognosis

Question 34

How should oligohydramnios be managed?

Answer 34

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.

Question 35

What is polyhydramnios?

Answer 35

Increase amniotic fluid volume

Question 36

What causes polyhydramnios?

Answer 36

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)

Question 37

What are the complications from polyhydramnios?

Answer 37

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

Question 38

How should polyhydramnios be investigated?

Answer 38

GTT to exclude maternal diabetes

USS examination of foetus

Question 39

How should polyhydramnios be managed?

Answer 39

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