Week 3 - G - Small for gestational age babies, intrauterine growth restirctions, assesing foetal wellbeing

Question 1

When looking at babies, some babies are small for gestational age What are the two different categories of baby that are small for gestational age?

Answer 1

Intrauterine growth restriction (IUGR) and Constitutionally small - healthy and small baby

Question 2

What is considered a term birth? Preterm births can also cause the baby to be small What is considered a preterm birht?

Answer 2

• Term birth - anything between 37+0 weeks and before 40+6 weeks
• Preterm birth - between 24+0 weeks gestation and 36+6 weeks gestation
• Late term: Your baby is born between 41 weeks, 0 days and 41 weeks, 6 days.
• Post term: Your baby is born after 42 weeks, 0 days.

Survival rates: * 24 weeks approx 20-30% * 27 weeks 80% * 32 weeks >95%

Question 3

What is the most common reason for a preterm birth?

Answer 3

Babies who were born early most commonly is idiopathic

Question 4

INfection cause cause preterm births but usually these infections are ones which cause systemic upset Give an example

Answer 4

Pyelnephritis (infection of the kidneys) - can cause systemic effects leading to a premature birth

Question 5

Parity of what increases the chances of pre term births?

Answer 5

Parity of 0 or >5 will increase the chances of a pre-term birth

Question 6

Pre-term birth 25% planned caesarean section * Sever pre-eclampsia, kidney disease or poor fetal development. 20% premature rupture of membranes 25% emergency event * Placental abruption, infection, eclampsia 40% cause unknown What is premature rupture of membranes known as?

Answer 6

This is preterm pre-labour rupture of membranes (P-PROM) - poses a high risk for infection and antibiotics should be taken

Question 7

If there is preterm - prelabour rupture of membranes, what antibitoic is the mother started on?

Answer 7

The mother is started on erythromycin for 10 days - this increases the time between membrane rupture and delivery - safer to deliver the baby nearer term and decreases risk of infection

Question 8

If a mother develops a UTI during pregnancy, what is the treatment for each trimester?

Answer 8

* 1st or 2nd trimester nitrofurantoin * 3rd trimester trimethoprim * 2nd line (any trimester) cefalexin

Question 9

Infant with a birthweight that is less than 10th centile for gestation corrected for maternal height, weight, fetal sex and birth order. What is this infant known as?

Answer 9

The infant with a birthweight less than 10th centile for gestation is known as small for gestational age (SGA)

Question 10

Intrauterine growth restrictions means the infant has poor growth - can be due to maernal, feotal or placental causes What are maternal factors that may complicate to IUGR? What maternal condition can restrict growth?

Answer 10

Lifestyle * Alcohol * Smoking * Drugs Height and weight Age Hypertension can restrict growth

Question 11

INfection and congenital abnormalities (ie one kidney) or chromsomal abnormalities of the foetus can cause IUGR Name some bacterial infections common in preterm chidlren?

Answer 11

CMV infection - HHV5 Rubella Toxoplasmosis Chicken pox - caused by varicella zoster virus

Question 12

Placental factors such as infarct and abruption are also causes of IUGR What is palcental abruption? What may abruption and infacrtion be secondary to?

Answer 12

Placental abruption is where the placenta partially or completely detaches from the uterus

Both can be secondary to hypertension

Question 13

Define small for gestation age again?

What does it mean for symmetrical or asymmetrical intrauterine growth restriction?

Answer 13

Small for gestational age - infant with a birthweight less than the 10th centile for gestation corrected maternal height, weight, foetal sex and birth order

• Symmetrical means small head and body
• Asymmetrical means one is small whislt the other is normal

Question 14

What causes an asymetrical growth restriction?

Answer 14

This is when there is placental insufficiency meaning the babies head is usually spared but it has been starved It occurs when the placenta does not develop properly, or is damaged. It is a blood flow disorder marked by a reduction in the mother’s blood supply.

Question 15

Consequences of being growth restricted They baby antenatally can become hypoxic What can hypoxia do to the brain?

Answer 15

Hypoxia can cause damage to the brain as it starves it of oxygen leading to cerebral palsy

Question 16

What are poor clinical features for poor growth in a baby?

Answer 16

Reduced fundal height in comparison to gestational age Reduced liquor Reduced foetal movements - a baby who is struggling for oxygen will lie still

Question 17

When measuring the fundal height, how accurate should it be for gestational age? When do foetal movements normally occur roughly?

Answer 17

Fundal height should be within +/- 2 weeks of gestational age Foetal movements occur around 18-20 weeks although can begin earlier or later

Question 18

Assessment of foeetal wellbeing

• * Assessment of growth
• * Cardiotocography
• * Biophysical assessment
• * Doppler ultrasound

No need to carry out these assessments in a low risk delivery

On an ultrasound scan, what measurements are taken to predict foetal weight?

Answer 18

Foetal head circumference Femur length and Waist circumference

Left image is the babies head circumference

Right image is the waist circumference (would also measure femur length)

Question 19

To assess the foetal wellbeing - cardiotoco graphy can also be carried out - this is where the foetal heart response is measured in response to uterine contractions Two belts on the tummy- one picks up fetal heart rate on ultrasound doppler. Other one- picks up contractions. To interpret a CTG you need a structured method of assessing its various characteristics. The most popular structure can be remembered using the acronym DR C BRAVADO. What does acronym stand for?

Answer 19

• DR - define risk
• C - contractions
• BRA -Baseline RAte
• V - variability
• A - Accelerations
• D - Decelerations
• O - overall impression

Question 20

First stage for interpreting a cardiotocograph is determining whether the pregnancy is low or high risk Next determinen the contractios in 10 minutes? On the chart, each biq square is one minute

Answer 20

2/3 in 10 minutes for this chart

Question 21

The baseline rate is the average heart rate of the fetus within a 10-minute window. Look at the CTG and assess what the average heart rate has been over the last 10 minutes. What is normal foetal heart rate between? Should you include accerlations and decelerations when determinign the foetal heart rtae?

Answer 21

120-160 bpm

Do not include accelerations and decelerations when determining the baseline heart rate

Question 22

What is foetal tachycardia and bradycardia defined as?

Answer 22

Feotal tachycardia - basleline heart rate greater than 160 bpm Foetal bradycardia - baseline heart rate slower than 100bpm for at least 3 minutes

Question 23

Baseline variability refers to the variation of fetal heart rate from one beat to the next. What should the heart rate vary from per beat?

Answer 23

The variability within the baseline which should be > 5bpm

Question 24

What may reduced variability in the foetal heart rate be a sign of?

Answer 24

Foetal sleeping - shouldnt last longer than 40 minutes Drugs Prematurity - before 28 weeks Fetal acidosis (due to hypoxia)

Question 25

Accelerations are an abrupt increase in the baseline fetal heart rate of greater than 15 bpm for greater than 15 seconds. ¹ What are normal accelerations in response to the contractions?

Answer 25

A normal acceleration occurs at the start of the uterine contraction and returns to baseline by the end or sometimes just after the contraction

Question 26

Decelerations are an abrupt decrease in the baseline fetal heart rate of greater than 15 bpm for greater than 15 seconds. There are a number of different types of decelerations, each with varying significance. What are the different types of decelerations?

Answer 26

Early Variable decelerations Late decelerations

Question 27

Which decelerations are considered phsyiological? describe it

Answer 27

Early deceleration Early decelerations start when the uterine contraction begins and recover when uterine contraction stops. This is due to increased fetal intracranial pressure causing increased vagal tone. It therefore quickly resolves once the uterine contraction ends and intracranial pressure reduces. This type of deceleration is therefore considered to be physiological and not pathological.

Question 28

Late decelerations are worrying What do they indicate as a cause? Describe a late deceleraiton Variable decelerations are similar but occur with the contraction, usually due to cord compression - variable duration however

Answer 28

They indicate there is an insufficient blood supply to the uterus and placenta * Late decelerations begin at the peak of the uterine contraction and recover after the contraction ends. * This type of deceleration indicates there is insufficient blood flow to the uterus and placenta. * As a result, blood flow to the fetus is significantly reduced causing fetal hypoxia and acidosis.

Question 29

The presence of late decelerations is concerning and fetal blood sampling for pH is indicated. If the pH is acidotic, what is recommended?

Answer 29

If pH is acidotic, indicates foetal hypoxia and urgent C-section is recommended

Question 30

DR C BRAVADO Overall impression is described as reassuring, non reassuring and abnromal What are the three main sections of the acronymm that acount for the overall impression?

Answer 30

The Baseline rate

The baseline variability

And The Decelerations

Question 31

What does a sinusoidal baseline vaiability indicate? - this is very rare and is abnormal and needs urgent attention

Answer 31

Indicates severe foetal hypoxia Severe foetal anaemia Foetal/maternal haemorrhage

Question 32

To assess foetal well-being, biophysical profile of the foetus is carried out This assesses foetal movement, tone, breathing movements and liquor volume What is the one other aspect assessed in the biophysical profle of the foetus? Score is out of 10 What score is satifacotry? What score should be repeated? What score indicated delivery?

Answer 32

8outof10 -satisfactor 4-6 - indicates repeat 0-2 - delivery