Prematurity Flashcards
What are the causes of prematurity?
- Unknown (most common)
- Smoking
- Low socio-economic status
- Malnutrition
- History of - prematurity, infection, PET, DM, polyhydramnios, closely spaced pregnancy, multiple pregnancy, uterine malformations, placental issues, PROM.
What is this describing?
<37/40 completed weeks gestation.
Preterm
What is this describing?
<2500g regardless of gestational age, may not be SGA if preterm.
Low birth weight
What is this describing?
<1500g regardless of gestational age, may not be SGA if preterm.
Very low birth weight
What is this describing?
<1000g regardless of gestational age, may not be SGA if preterm.
Extremely low birth weight
What is this describing?
Birth weight below the 10th percentile for gestational age.
Small for gestational age (SGA)
What is this describing?
Failure of growth in utero which may/may not result in a baby being SGA.
Intrauterine growth restriction (IUGR)
What is this describing?
All growth parameters in an infant are small, suggesting foetus was affected from early pregnancy either due to chromosomal abnormalities or being constitutionally small.
Symmetrical SGA
What is this describing?
Weight of an infant is affected but length and head circumference spared. Usually due to IUGR and an insult later in pregnancy (placental/PET).
Asymmetrical SGA
What are the causes of symmetrical SGA?
Malnutrition, maternal hypoxia, alcohol, smoking, chromosomal, congenital infection.
What are the causes of asymmetrical SGA?
PET, thrombosis/infarction (sickle cell)
What causes hypothermia in a premature infant and how is it managed?
- Thin skin, large body surface area, limited SC fat.
2. Humidified incubator, hat on head.
What causes infection in a premature infant and how is it managed?
- Less passive immunity as maternal Igs cross placenta at 30/40.
- IV Abx, antibodies against specific infection, prophylactic anti-fungal.
What causes feeding difficulties in preterm infants, what can it cause, and how is it managed?
- No suck and swallow reflex until 34/40.
- Necrotising enterocolitis
- <34/40 TPN with milk via NG tube, breastmilk preferred as formula can increase risk of NEC.
What will all babies born <28/40 have and how is it defined?
- Apnoea
2. Pause of breathing of >20s
What are the causes of apnoea of prematurity?
- Immature respiratory drive
2. GORD, infection, seizures, hypoxia
What is the management of apnoea of prematurity?
- Mechanical ventilation, surfactant
- Caffeine daily to stimulate respiratory centre of brain.
- Most resolve by 34/40 and caffeine is stopped.
What type of brain bleed can occur in prematurity?
Intraventricular haemorrhage
What is the cause of intraventricular haemorrhage in neonates?
Prematurity
What is the pathophysiology of intraventricular haemorrhage in prematurity?
Small vessels in subpendymal germinal matrix rupture. Matrix prominent between 24-34/40 then regresses by term, so it is rare in term neonates.
What are the risk factors for intraventricular haemorrhage in prematurity?
- Hypertension
- Hypotension
- High pCO2
- Low O2
What is this a presentation of?
Usually asymptomatic. Seizures, bulging fontanelle, prolonged apnoea, Hb drop. Premature infant.
Intraventricular haemorrhage
How is intraventricular haemorrhage of prematurity diagnosed?
Cranial USS, babies born <32/40 have 3 scans in 1st week of life.
What is the management for intraventricular haemorrhage of prematurity?
- Reduce risk factors.
2. If hydrocephalus is increasing, drain using LP or shunt, otherwise it is self-resolving.
What is this describing?
Abnormal proliferation of retinal blood vessels of premature babies.
Retinopathy of prematurity
What are the risk factors for retinopathy of prematurity?
- Low birth weight, prematurity
2. Large fluctuations of oxygen, prolonged oxygen therapy.
How is retinopathy of prematurity diagnosed?
- Screening through initial ophthalmoscopy with pupil dilation.
- Screen all at <32/40 or weight <1500g
What are the complications of retinopathy of prematurity?
Vitreous haemorrhage, retinal detachment, blindness, visual problems.
What is the management for retinopathy of prematurity?
- Usually resolves spontaneously
- Treat for severe stages with diode laser therapy under GA
- Consider bevacizumab (anti-VEGF)
What is this describing?
Serious acute inflammatory bowel condition that occurs in the 2nd/3rd week of life in premature babies.
Necrotising enterocolitis
What is the cause of necrotising enterocolitis of prematurity?
- Necrosis of the bowel due to lack of blood flow.
2. Associated with prematurity, hypoxia, formula milk feeds.
What is this a presentation of?
Early - bile stained aspirates from stomach, abdominal distension, bloody stools, poor feeding, lethargy, vomiting.
Late - abdominal discolouration, perforation, peritonitis, shock, DIC.
Necrotising enterocolitis
How is necrotising enterocolitis of prematurity diagnosed?
- Clinical diagnosis
- Abdominal x-ray - dilated bowel, pneumatosis intestinalis (gas in bowel wall), bowel perforation (free air in abdomen)
How is necrotising enterocolitis of prematurity prevented?
- Introduce feeds gradually
- Breast milk
- Probiotics
What is the active management for necrotising enterocolitis of prematurity?
- Stop oral feeding (except probiotics), replace with TPN.
- Analgesia
- Culture faeces, crossmatch (risk of anaemia)
- Abx - cefotaxime and vancomycin
What is the surgical management for necrotising enterocolitis of prematurity?
If bowel perforation - conservative with peritoneal drainage or laparotomy to remove affected bowel and temporary stoma.
