Problems of Low Birthweight Infant

Question 1

What is the median UK birthweight at term?

Answer 1

3.480kg

Question 2

Below what weight is low birth weight

Answer 2

<2500g

Question 3

Below what weight is very low birth weight

Answer 3

<1500g

Question 4

Define prematurity

Answer 4

Birth before 37 weeks gestation

Question 5

Define small for gestational age

Answer 5

Birth weight below 10th centile

Question 6

What is fetal growth restriction

Answer 6

Failure of achieve normal rate of foetal growth

Question 7

What are the consequences of a small for gestational age baby

Answer 7

Complications of foetal growth restriction

Very long term health problems

Question 8

What are the consequences of a premature baby

Answer 8

Neurodevelopmental disorder

Question 9

Name 5 acquired causes of SGA baby

Answer 9

• Utero-placental insufficiency
• Congenital infection
• Smoking
• Maternal chronic illness
• Multiple pregnancy

Question 10

What are the consequences of congenital CMV on the brain

Answer 10

Hydrocephalus and calcification

Question 11

What is genetic basis of Edwards syndrome

Answer 11

Trisomy 18

Question 12

What does Edwards syndrome baby look like

Answer 12

Small with congenital abnormalities (clenched fist)

Question 13

In which 2 ways can utero-placental insufficiency lead to untrauterine growth restriction

Answer 13

• Failure of syncytiotrophoblast invasion of high resistance spiral arteries
• Poor placental development with raised resistance in placental vascular bed

Question 14

How can hypoxic placenta be detected

Answer 14

Doppler ultrasound in uterine arteries and foetal circulation

Question 15

What is meant by brain sparing circulatory redistribution

Answer 15

When there is limited oxygen, baby’s circulation prioritises blood floow to deliver oxygen to brain and heart at expense of other parts of body

Question 16

Where does SGA baby have problems with temperature control

Answer 16

Increased SA:V ratio
Reduced adipose tissue insulation
Reduced capacity for thermogenesis

Question 17

How is hypoglycaemia treated in SGA baby

Answer 17

IV dextrose

Question 18

What does symptomatic hypooglycaemia look like, and what does it suggest

Answer 18

Lethargy and fits

Risk of adverse neuro-developmental outcome

Question 19

What is necrotising enterocolitis

Answer 19

Acute bacterial invasion/ inflammation/ necrosis of bowel with gas formation in bowel wall

Question 20

Why is SGA baby at risk of hypoglycaemia

Answer 20

Low glycogen reserves

Question 21

What adult diseases is low birth weight associated with

Answer 21

Diabetes
HT
Coronary heart disease
Stroke
Chronic bronchitis

Question 22

What can cause spontaneous preterm labour

Answer 22

Infection/ ruptured membranes
Cervical incompetence
Polyhydramnios

Question 23

Name 6 systems that may be affected by prematurity

Answer 23

Temp control
Resp
Cardiovascular
Nutritional
Infection
Neurological

Question 24

Why is preterm baby at high risk of heat loss?

Answer 24

Large SA: body mass ratio
Thin skin
Less adipose tissue
Wet at birth
Can't shiver
Poor metabolic reserve

Question 25

Why is temperature set as it is in modern incubators

Answer 25

Set to help baby maintain temperature but at minimal metabolic cost- neutral thermal environment

Question 26

What respiratory structural immaturity can be seen in premature infants

Answer 26

Primitive alveolar development | Susceptibility to oxygen toxicity and barotrauma

Question 27

What respiratory functional immaturities can be seen in premature infants

Answer 27

Surfactant deficiency | Lack of resp drive

Question 28

Why are premature babies more susceptible to infection

Answer 28

Immature immune system | Instrumentation of airway

Question 29

3 short term respiratory clinical problems of premature babies

Answer 29

Respiratory distress syndrome Pneumonia Apnoea of prematurity

Question 30

Long term respiratory clinical problem of premature baby

Answer 30

Chronic lung disease of infancy

Question 31

What is found at the air-liquid interface in alveoli and what does it consist of

Answer 31

Surfactant- monolayer of phospholipid molecules | Consists of DPPC and phosphatidylglycerol

Question 32

What stabilises surfactant

Answer 32

Surfactant protein B

Question 33

What is the function of surfactant

Answer 33

Reduces surface tension at air-fluid interface

Question 34

What is RDS

Answer 34

Respiratory distress syndrome Lack of surfactant in premature baby Tachypnoea, expiratory grunting, recession

Question 35

4 ways to prevent RDS

Answer 35

Ante-natal steroids Avoidance of intrauterine hypoxia Prophylactic surfactant treatment Keep warm, avoid acidosis

Question 36

What causes chronic lung disease of infancy

Answer 36

Lung injury in preterm infant | Inflammation, fibrosis, emphysema

Question 37

What is PPHN

Answer 37

Persistent pulmonary hypertension of the newborn

Question 38

How many caloiries does preterm baby need to grow a day

Answer 38

110-135

Question 39

How does the baby receive nutrition in utero

Answer 39

Foetus swallows amniotic fluid | Nutrition is provided continuously across placenta

Question 40

What are the challenges in feeding a preterm baby

Answer 40

Immature suckling Poor gut motility May not tolerate enteral feeds

Question 41

What happens if baby is not fed

Answer 41

Gut mucosa atrophies

Question 42

What is pneumotosis

Answer 42

Gas formation in bowel wall

Question 43

Risk factors for necrotising enterocolitis

Answer 43

Prematurity, hypoxia, infection, enteral feeding

Question 44

Clinical presentation of nectorising enterocolitis

Answer 44

Abdo distention Tenderness Discolouration Blood in stools

Question 45

Treatment of necrotising enterocolitis

Answer 45

Stop feeds Give antibiotics Sometimes surgery

Question 46

What bacterias most commonly cause infections within 48 hours of birth

Answer 46

Group B beta haemolytic strep | E coli

Question 47

What bacterias most commonly cause infections >48 hours after birth (hospital acquried)

Answer 47

Coagulase negative straphylococci | Gram negative organisms that colonise intestine

Question 48

What immune protection is present in full term baby but not preterm

Answer 48

Transplacental IgG in 3rd trimester IgA and immunlogically active cell in colostrum Skin barrier Acquisition of normal flora from mother

Question 49

Why is preterm baby immunocompromised?

Answer 49

No usual full term benefits Nursed in bacterially hostile environment Given broad spectrum antibiotics Invasive procedures breach host defeces

Question 50

Why are preterm babies susceptible to Periventricular haemorrhage

Answer 50

Germinal matrix in floor of lateral ventricles is vascular due to active glial and neuronal proliferation Poor control of brain perfusion

Question 51

What is periventricular leucomalacia

Answer 51

Ischaemia of periventricular white matter

Question 52

What are the risk factors for periventricular haemorrhage

Answer 52

``` Prematurity RDS Pneumothorax Hypercapnia Acidosis Hypotension ```

Question 53

What % of babies <1500g develop cerebral palsy

Answer 53

10

Question 54

What long term problems in the brain result from prematurity

Answer 54

Cognitive and behavioural problems Sensory impairment Minor hearing and vidual impairment