Preterm Infants

Question 1

What is the definition of preterm?

Answer 1

A birth that occurs before 37 weeks of completed gestation

Question 2

What is the definition of term?

Answer 2

A birth between 37-42 weeks of gestation

Question 3

What is the definition of post-term?

Answer 3

A birth that occurs after 42 completed weeks of gestation

Question 4

What does post-date mean?

Answer 4

A birth that occurs after the expected date of delivery

Question 5

What time period does foetal loss encompass?

Answer 5

Less than 22 weeks gestation

Question 6

What are the different classes of preterm births?

Answer 6

Extremely preterm = 23-27 weeks gestation

Very preterm = 23-31 weeks gestation

Question 7

What public health intervention caused a fall in the preterm birth rates?

Answer 7

The smoking ban = caused decline of 10%

Question 8

How many women in Scotland smoke during their pregnancy?

Answer 8

1 in 12 = of these women, 10% start smoking in the later stages of pregnancy

Question 9

When do over half of childhood deaths occur?

Answer 9

In the first year of life = strong association with preterm birth and low birth weight

Question 10

What is the association between preterm births and death?

Answer 10

10 times higher risk of death when born before 32 weeks

Question 11

Why is prematurity rising globally?

Answer 11

Increased maternal age, increased pregnancy-related complications, greater use of infertility treatments, more C-section births before term

Question 12

What are the most common reasons for preterm births?

Answer 12

Multiple pregnancies = 9 times higher risk of prematurity
Spontaneous preterm labour
Preterm prelabour rupture of membranes

Question 13

Does having more than one preterm delivery increase the risk of future preterm births?

Answer 13

Yes = >2 preterm deliveries increases risk of another premature baby by 70%

Question 14

What impact does an abnormally shaped uterus have on preterm birth?

Answer 14

Increases risk by 19%

Question 15

What are some risk factors for preterm birth?

Answer 15

Interval of less than 6 months between pregnancies
Conceived through IVF
Smoking, alcohol and illicit drugs
Poor nutrition, high BP, diabetes, multiple miscarriages or abortions

Question 16

What are the main differences between term and preterm babies that need to be considered when managing a preterm baby?

Answer 16

Need more help to stay warm, more fragile lungs, don’t breathe effectively, have fewer reserves, delay cord clamping if possible

Question 17

How are preterm babies kept warm?

Answer 17

Using a plastic bag under a radiant heater = baby goes in bag feet first

Question 18

What are common problems in preterm babies?

Answer 18

Temperature control, feeding/nutrition, sepsis, metabolic, ROP, system immaturity/dysfunction

Question 19

What are some problems caused by system immaturity/dysfunction in preterm babies?

Answer 19

Respiratory distress syndrome (RDS)
Patent ductus arteriosus (PDA)
Intraventricular haemorrhage (IVH)
Necrotising enterocolitis (NEC)

Question 20

What is low admission temperature a risk factor for?

Answer 20

Neonatal death = hypothermia increases severity of all preterm morbidities

Question 21

What is mostly responsible for hypothermia in newborns?

Answer 21

More due to lack of knowledge than lack of equipment

Question 22

Why is thermal regulation ineffective in preterm babies?

Answer 22

Low BMR
Minimal muscular activity
Subcutaneous fat insulation is negligible
High ratio of surface area to body mass

Question 23

What does maintaining the temperature of a baby prevent?

Answer 23

Hypoglycaemia and hypoxia

Question 24

What is the treatment for hypothermia?

Answer 24

Wrap/bags, skin to skin contact, transwarmer mattress, prewarmed incubator

Question 25

Why do preterm babies have an increased risk of nutritional compromise?

Answer 25

Limited nutrient reserves, gut immaturity, immature metabolic pathways, increased nutrient demands

Question 26

How much must the weight of a preterm baby be increased by?

Answer 26

Must increase by 7 times in 14-16 weeks

Question 27

How may babies be supported nutritionally?

Answer 27

Breastmilk is best Total parenteral nutrition may be used Formula feeding rarely used and isn't advocated

Question 28

What must any breastmilk donor undergo?

Answer 28

Viral screening

Question 29

How does protein energy malnutrition arise in babies being fed using formula?

Answer 29

Demand of baby increases as it grows but parents often don't increase the amount of formula they are buying

Question 30

What are the two types of neonatal sepsis?

Answer 30

``` Early onset (EOS) = mainly due to bacteria before and during delivery Late onset (LOS) = acquired after delivery (nosocomial or community sources) ```

Question 31

What organisms are implicated in neonatal sepsis?

Answer 31

Early onset = Group B strep, gram negatives (lower GI) | Late onset = gram negatives, coagulase negative staph, staph aureus

Question 32

Why are preterm babies at risk of neonatal sepsis?

Answer 32

Immature immune system, intensive care environment, indwelling tubes and lines

Question 33

How is neonatal sepsis managed?

Answer 33

Prevention, hand washing, infection screening, antibiotics, supportive measures

Question 34

What are some respiratory complications associated with preterm birth?

Answer 34

Respiratory distress syndrome, apnoea of prematurity, bronchopulmonary dysplasia

Question 35

What causes respiratory distress syndrome?

Answer 35

Primary pathology = surfactant deficiency, structural immaturity Secondary pathology = may be due to intubation

Question 36

What is respiratory distress syndrome?

Answer 36

Hyaline membrane disease due to lack of surfactant

Question 37

How does alveolar damage occur in respiratory distress syndrome?

Answer 37

Formation of exudate from leaky capillaries, inflammation, repair

Question 38

Is respiratory distress syndrome common in preterm babies?

Answer 38

Yes = occurs in 75% of babies born before 29 weeks

Question 39

What are the clinical features of respiratory distress syndrome?

Answer 39

Tachypnoea, grunting, intercostal recessions, nasal flaring, cyanosis, respiratory distress, worsens over minutes to hours

Question 40

What is the natural history of respiratory distress syndrome?

Answer 40

Gradual worsening over 2-4 days then gradual improvement

Question 41

How is respiratory distress syndrome treated?

Answer 41

Maternal steroid, surfactant replacement, ventilation

Question 42

Why is blood shunted away from the lungs by the ductus arteriosus in normal foetal circulation?

Answer 42

Blood mostly bypasses the lungs in order to supply the other developing organs (e.g the brain)

Question 43

What does a patent ductus arteriosus cause?

Answer 43

It increases the workload of the heart

Question 44

How are intraventricular haemorrhages graded?

Answer 44

From 1 to 4

Question 45

What occurs is grade 1 and 2 intraventricular haemorrhages?

Answer 45

Neurodevelopmental delay up to 20%, mortality is 10%

Question 46

What occurs in grade 3 and 4 intraventricular haemorrhages?

Answer 46

Neurodevelopmental delay up to 80%, mortality is 50%

Question 47

Why does necrotising enterocolitis occur?

Answer 47

Gut of baby is not ready to process and digest milk = gut bacteria translocates across broken barrier into bloodstream causing sepsis

Question 48

What babies are more commonly affected by necrotising enterocolitis?

Answer 48

Usually extremely preterm babies

Question 49

What are some features of retinopathy of prematurity?

Answer 49

Usually presents 6-8 weeks after delivery, common in babies born before 32 weeks, screened for every 4 weeks after birth

Question 50

What are some metabolic complications associated with preterm births?

Answer 50

``` Early = hypoglycaemia, hyponatraemia Late = osteopenia of prematurity (due to increased demand for minerals for growth) ```

Question 51

How much difference does each day make in the survival of extremely preterm babies?

Answer 51

Very important = survival increases by 2% each day

Question 52

What has the trend been in the survival of preterm babies?

Answer 52

Trend has been increasing since 1998

Question 53

What two treatments have made the most difference n improving the survival of preterm babies?

Answer 53

Antenatal steroids and surfactant replacements

Question 54

How common are preterm births?

Answer 54

About 6% of births are preterm

Question 55

Are the survival rates of preterm babies different depending on gender?

Answer 55

Yes = girls have higher survival rates than boys when born preterm