Small or Preterm Babies

Question 1

What are the definitions based on weight for small babies and gestational weeks?

Answer 1

• Weight
  
  • low baby weight <2500g
  • very low birth weight <1500g
  • extremely low <1000g
• Gestation
  
  • preterm <37 weeks
  • very preterm <32 weeks
  • extremely preterm <28 weeks
• small for gestational age
  
  • large >90th centile for age+gender
  • small <10th centile for age + gender

Question 2

What are some causes for being small for gestational age?

Answer 2

• normal - familial
• Maternal
  
  • environmental (e.g. famine)
  • PE
  • HTN
  • renal disorders
  • CHD
  • drugs (illicit e.g. cocaine)
  • smoking
• Foetal
  
  • congenital infection
  • chromosomal
  • major malformations
• Placental
  
  • multiple pregnancies with unequal sharing (e.g. twins)
  • pre-eclampsia
  • TE/infarction
  • poor implantation
  • malformations
  • placental insufficiency

Question 3

What are the consequences of being small or preterm?

Answer 3

• thermal
  
  • more brain fat in small gestational age babies vs preterm babies. Hypothermia
• Nutritional
  
  • more trouble with BSL - don’t catch up
  • special care nursery
  • jaundice, feeding, fluid, often less mature body systems
• Respiratory:
  
  • surfactant develops at 32 weeks. Rarely a problem but can be.
• CVD
  
  • involution of blood vessels get intraventricular haemorrhage
  • necrotising enterocolitis common in preterm.
  • anaemia

Question 4

What are some common causes for preterm birth?

Answer 4

• idiopathic most cases
• preterm labour/PROM
• cervical incompetence
• multiple pregnancies
• APH (antepartum haemorrhage)
• uterine abnormalities
• indicated delivery (foetal/maternal)

Question 5

What is the immediate management of a preterm infant?

Answer 5

• Keep them pink, warm, sweet
  
  • Oxygen
  • Warm
  • BSL
• Breathing
  
  • resp distress
  • Dx
    
    • hyaline membrane disease (HMD)
      
      • due to surfactant insufficiency
      • treatment - pressure support and artificial surfactant
    • pneumonia
    • wet lung (failure to move amniotic fluid out of the airways)
  • oxygen
    
    • nasal prongs
    • masks
    • incubator
    • nasal CPAP
    • ETT
    • Cx - lung injury, pneumothorax, ROP (retinopathy of prematurity)
  • monitoring
    
    • sat probe (88-92% is good and >95% for term babies)
    • colour
    • pO2 (45-65mmHg, ABG, transcutaneous)
  • Warmth
    
    • 36.8 +/- 0.3 degrees (per axilla)
    • minimal losses (radiant warmer, dry them, incubator, glad bag)
  • Sweet
    
    • BSL >2.5mmol/L - glucose sticks not as effective at this low level
    • glucose via enteral (breastmilk) or parenteral - infusion 60ml/kg/day 10% breastmilk.

Question 6

What are mortality causes for different age groups?

Answer 6

• <28weeks
  
  • HMD + complications
    
    • ventilation can cause sudden pneumothorax and haemorrhages
  • sepsis/NEC = immature immunity
  • malformation
• 28-36weeks
  
  • sepsis
  • malformations
• improved - surfactant, more in-utero transfusions, more ICU.

Question 7

What are common impairments in preterm babies?

Answer 7

• cerebreal palsy
  
  • 10% of 22-27 weeks but 0% in term
• blindness (not common <0%)
• deafness (not common 2% 22-27wks)
• developmental delay
  
  • almost 50% in 22-27 weeks