Prematurity Flashcards
When is a child described as being premature?
Delivered at <37 weeks gestation
When is a child described as being of low birth weight (LBW)?
<2500g
When is a child described as being moderately premature?
Delivered at 35-37 weeks
When is a child described as being very premature?
Delivered at 29-34 weeks
When is a child described as being extremely premature?
Delivered at = 28 weeks
What are the RFs for prematurity?
- Previous prematurity
- Multiple gestation
- Cervical incompetence
- PROM
- Maternal infection
- Maternal chronic disease
- Maternal substance use, e.g. smoking
What are the 3 possible neurological consequences of prematurity?
- Intraventricular haemorrhage (IVH)
- Periventricular leukomalacia (PVL)
- Hypoxic ischaemic encephalopathy (HIE)
What is HIE?
Swelling and irritation of the brain caused by lack of oxygen
When may HIE occur?
- Failure of gas exchange across the placenta
- Interruption of the umbilical blood flow
- Inadequate maternal placental perfusion
- Compromised foetus
- Failure of cardiorespiratory adaptation at birth
What is the most common cause of neonatal seizures?
HIE
If a seizure is going to occur with HIE, when do they generally do so?
Within 24 hours of delivery
What neurological condition is associated with PVL?
CP
What cell produces surfactant?
Type II alveolar cells
At what point do these cells begin producing surfactant?
26 weeks at the earliest, so any baby born before this will certainly have inadequate surfactant
When is a child defined as having tachypnoea?
> 60
What is an infant trying to achieve by grunting?
Grunting attempts to create a positive airway pressure to maintain functional residual capacity
What is the characteristic appearance of RDS on XR?
Ground-glass
What drug may be given to reduce the risk of RDS if a premature delivery is imminent?
Maternal corticosteroids
What may be given to the infant post-delivery should they be suffering with RDS?
Synthetic surfactant therapy
When does the ductus arteriosus close in a full-term/normal BW infant?
Within 3 days of delivery
What happens if the DA DOESN’T close 3 days post-delivery?
Oxygenated blood of the aorta mixes with deoxygenated blood of the pulmonary artery. Results in tachycardia, SOB, difficulty feeding and a ‘machine-like’ heart murmur
Whom is at risk of non-DA closure?
LBW infants, i.e. often premature infants
What can be given to close the DA?
NSAIDs
How does NSAIDs close the DA?
They decrease prostaglandin synthesis, it being prostaglandin E1 that is responsible for the DA’s patency. Without prostaglandins the DA can not remain open
What is the most common neonatal surgical emergency?
Necrotising enterocolitis (NEC)
What part of the bowel is most commonly effect by NEC?
Terminal ileum + proximal colon
What may be protective against NEC?
Breast milk + antenatal steroids
What are the characteristic XR signs in NEC?
- Intramural air
- Distended bowel loops
- Air in portal tract
- (Air under diaphragm when bowel has perforated)
What oxygen sats are aimed for in a pre-term infant and why?
92-94% - because oxygen toxicity poses risk of retinopathy of prematurity (ROP)
What infants are screened for ROP?
Those born at:
- <32 weeks gestation
- <1500g BW
