Prematurity

Question 1

What is the classification for prematurity?

Answer 1

<37 weeks

Debate about viability (22-23 weeks)

Limitation is due to ability to survive without mother

Survivability increases with advancing age

Question 2

Considerations for preterm infant:

1. Temperature control: preterm babies have a high surface area to volume ratio therefore lose heat very quickly
   => their body immediately placed into a plastic bag on a heater to preserve heat.
   => Once on neonatal unit, placed into an incubator.
2. Breathing support i.e. ventilator, CPAP - as preterm babies have immature lungs
   => mum’s given steroid if known baby will be preterm - this helps to mature the baby’s lungs
3. CVS support - immature myocardium so may need ionotropes and changes in fluids to help support CVS

Answer 2

Considerations for preterm infant:

4. Immature gut - may develop necrotising enterocolitis
5. Feeding & nutrition
   => risk of hypoglycaemia as they can’t feed adequately due to small stomach and can’t suck before 34 weeks
   => fed milk using nasogastric tube
   => if too premature and unable to handle milk then given parental nutrition
6. Immune system immature - antibiotics for prevention
7. Immature brains and vessels in brain - risk of intravenous haemorrhage
   => if haemorrhage persist / ischaemic change as a result lead to neurodevelopment problems
   => retinopathy

Question 3

What are the causes of prematurity?

Answer 3

40% unknown

Smoking tobacco

Poverty

Malnutrition

Past hx of prematurity

Genito-urinary infection/chorioamnionitis

Pre-eclampsia

Diabetes

Polyhydraminos

Closely spaced pregnancies

Multiple pregnancies

Uterine malformation

Placenta previa / placental abruption / premature rupture of membrane

Labour induced early on purpose / accidentally

Question 4

How do you estimate the gestational age?

Answer 4

Check expected date of delivery - calculated from the last menstrual period (LMP) or ultrasound scan

If no scan or LMP, use Dubowitz score.

Question 5

What is the management for preterm babies?

Answer 5

In utero transfer meaning specialised neonatal centre for delivery (better outcomes)

Adequate resus once born

Take to NICU / SCBU

Plan supplemental breast milk or low birth weight formula if <2kg. Monitor and maintain blood glucose.

Encourage mother to express from day 1

Tube feed if oral feeds are not tolerated

If oral feeding is contraindicated e.g. in respiratory distress, IV feeding needed

Support parents

Question 6

Disability due to prematurity:

=> 23 weeks gestation = 5% had no to minor disability

=> Cerebral palsy, squint and retinopathy = common

=> Decreased numeracy if gestation is under 30 weeks assoc. with reduced grey matter in the left parietal lobe

Answer 6

Survival rates:

40% of infants born before 23 weeks die on labour ward

Of those surviving, 75% die on neonatal unit.

47% survive at 24 weeks and 67% survive a 25 weeks.