1. Prematurity
Dr Varsha Atul Shah
Dept of Neonatal and Developmental Medicine
Singapore General Hospital

2. Extremes of
Birth Weight
Neonatal
Hypoglycaemia
Prematurity

3. Preterm
Definition: < 37 completed Gestational weeks
• Gestational age assessment
– Obstetric information
• LMP, ultrasound, others (quickening, etc)
– Newborn information
• Neurological, physical
– Dubowitz Score, New Ballard Score
• Direct ophthalmoscopy of the lens

4. Dubowitz Score

5. New Ballard Score

6. Assessment of maturity by
examination of anterior
vascular capsule of the lens
Hittner et al

7. Incidence
Singapore
• Preterm births: 5-8 % of all births

8. Associated Factors
• Maternal
– Low socioeconomic status
– Lack of prenatal care
– Substance abuse, smoking
– Maternal age < 16yrs or > 35yrs
– Maternal illness e.g. renal, heart, lung, HPT, DM, etc
– Multiple gestation
– Prior preterm delivery
– Obstetric factors e.g. uterine malformations, cervical
incompetence, polyhydramnios, premature rupture of
membranes, infection (e.g. chorioamnionitis), placenta
praevia, abruptio, etc
– Abdominal trauma / surgery
• Foetal
– Foetal distress, IUGR, etc

9. Problems of Prematurity
• Related to difficulty in extrauterine
adaptation due to immaturity of organ
systems
• Degree of immaturity
– Appearance, behaviour, problems, clinical course
– Mildly preterm (35 - 36 wks)
– Moderately preterm (32 - 34 wks)
– Severely preterm (< 32 wks)

10. Management
• Prevention
– Obstetric Mx: maternal illness, infection
– Inhibition of preterm labour
– Steroids to facilitate lung maturation
Problems & Management:
• Initial, acute
• Long term

11. Initial Problems & Management
Immediate postnatal management
Temperature regulation
Respiratory
Neurologic
Cardiovascular
Haematologic
Gastrointestinal & Nutritional
Metabolic
Renal
Fluid & electrolyte
Infection
Ophthalmologic
Osteopenia
Liver
Surgical conditions
Immunisation
Social

12. Immediate Postnatal Management
• Delivery
– Appropriately equipped & staffed
• Resuscitation & stabilisation

13. Temperature Regulation
• Poor temperature control
– Hypothermia, hyperthermia
1. Immature heat regulatory centre
2. Impaired heat production
∀ ↓ brown fat, poor muscular activity, poor 02
consumption
3. Increased heat loss
∀ ↓ subcutaneous fat, ↑ surface area (large
surface area to body weight, extended position)

14. Management
• Achieve neutral thermal zone
i.e. environmental T0 at which O2
consumption is minimal yet sufficient to
maintain body T0
• Yet exposed to facilitate observation
• Heat shield, plastic wrap, cap
• Overhead radiant warmer
– Infant accessibility, rapid T0 response
• Closed incubator
↓ insensible H2O loss, barrier to infection

15. Overhead radiant warmer
Closed incubator

16. Respiratory
• Asphyxia
– Poor adaptation to air breathing
– Perinatal depression at delivery
• Periodic breathing - jerky, irregular
• Apnoea
– Immature respiratory centre
– Small nasal passages & airways
– Weak respiratory muscles
– Compliant thoracic cage

17. • Respiratory distress syndrome (HMD)
• Aspiration pneumonia
– Regurgitate easily
– Uncoordinate suck & swallow
– Weak gag, cough reflex
• Chronic lung disease
– Acute & continued lung injury (surfactant
deficiency, pulmonary oedema, O2 exposure, mechanical
ventilation, inflammation) with abnormal repair
• Subglottic stenosis

18. Hyaline membrane disease
Subcostal retractions

19. Management
• Assisted ventilation
– Tracheal intubation & mechanical ventilation
– CPAP (Continuous Positive Airway Pressure)
– O2 therapy
• Medication
– Surfactant
– Aminophylline, caffeine
– Diuretics, steroids

20. Intubated
CPAP
Intranasal oxygen

21. Neurologic
• Hypotonic
• Perinatal depression
• Cerebral ischaemia & intracranial
haemorrhage
– Germinal layer vascular with little supporting
tissue
– Prone to hypoxia
– Impaired ability to regulate cerebral blood flow

22. Cardiovascular
• Hypotension
– Hypovolaemia, cardiac dysfunction, vasodilation
(sepsis)
Management
– Fluid resuscitation
– Inotropes

23. • Patent ductus arteriosus (PDA), CCF
Management
– Usually only requires conservative Mx
• Adequate oxygenation, fluid restriction
– Medical Mx: Prostaglandin antagonist
(indomethacin, ibuprofen)
– Surgical Mx: PDA ligation

24. Haematologic
• Anaemia
– Iatrogenic losses
– Haemorrhage, haemolysis
– Inadequate production
Management
• Minimizing blood loss
• Transfusion
• Iron supplement
• Misc: erythropoietin

25. ∀ ↑ susceptibility to hyperbilirubinaemia &
kernicterus
1. ↑ bilirubin production
∀ ↓ rbc lifespan, ↑ haemorrhage & haemolysis
2. ↓ bilirubin excretion
• impaired uptake & conjugation by liver,
↓ excretion via bile
3. ↓ bilirubin binding capacity
∀ ↓ serum albumin, hypothermia, acidosis
4. Permeable blood brain barrier
Management
– Careful monitoring of bilirubin levels
– Phototherapy
– Exchange transfusion

26. Phototherapy, preterm infant, on CPAP, incubator

27. Gastrointestinal & Nutritional
• Many preterm infants are unable to suck &
swallow effectively
– Coordination of suck with swallow only occurs
≥ ~ 32 - 34 wks
• Feed intolerance
↓ intestinal motility
• Necrotising enterocolitis

28. NEC
Gross abdominal distension
Shiny, oedematous, anterior
abdominal wall with distended vessels

29. Management
– Specific attention to type (expressed breast
milk & human milk fortifiers, preterm formula),
amount & route of feeding
– Gavage feeding
– Parenteral nutrition
– Multivitamin

30. Long line for TPN
Tube feeding

31. Metabolic
• Glucose (hypoglycaemia)
• Calcium (hypocalcaemia)

32. Renal
• Immature kidneys
– Low GFR & inability to handle water, solute &
acid loads
– Drug dosage adjusted

33. Fluid & Electrolyte
Fluid & electrolyte management difficult:
• High insensible H2O losses
– Skin loss, ventilation
• Renal function
• Aim
– Normal glucose, electrolyte & fluid balance

34. Infection
• Increased susceptibility
1. ↓ resistance
– Impaired humoral & cellular response
– Skin barrier
2. ↑ opportunity for infection
– Natural defense bypassed - lines, procedures
(e.g. Staphylococcal infection)
– Prolonged hospitalisation, with other infants
– Use of antibiotics
– Nosocomial infection, fungal infection

35. Increased risk for nosocomial
infection

36. Ophthalmologic
• Retinopathy of prematurity
– Disorder of developing retinal vasculature
Osteopenia
• Deficiency of calcium, phosphate & vit D

37. Liver
• Cholestatic jaundice
– TPN, infection
Surgical Conditions
• Inguinal hernia

38. Immunisation
• Immunised according to chronological age
• No contraindication in infants with stable
neurologic condition

39. Social
• Financial
• Psychosocial & Emotional

40. Mortality Rates
Gestational Age Mortality
• > 30wks < 5%
• 27 - 30wks 5 - 10%
• 25 - 26wks 10 - 50%
• 23 - 24wks 50 - 90%
• < 23wks > 97%

41. Survival Rates
Birth Weight Survival
• < 1000g 80%
• < 1500g 90%
• > 1500g 99%

42. Long Term Problems & Management

43. Long Term Problems
• Preterm infants are vulnerable to wide
spectrum of morbidity
• Severe impairment occurs in a small
population
• Prevalence of lesser morbidities less
clearly defined

44. Developmental Disability
• Major handicaps
– Cerebral palsy, mental retardation

45. • Sensory impairments
• Hearing loss, visual impairment
• Minimal cerebral dysfunction
– Language disorders, learning disability,
hyperactivity, attention deficits, behavioural
disorders

46. Medical Problems
• Chronic lung disease
– Increased severity respiratory infections
• Hydrocephalus, epilepsy
• Poor growth
• Increased rates of postneonatal illness &
rehospitalisation
• SIDS

47. Social
• Increased risk of child abuse & neglect
• Financial
• Psychosocial & Emotional
• Marital discord
• Parent support groups
• Light Weight Club
• Club Rainbow

48. Long Term Disability Rates
BW CP MR Sensory impr
• < 1500g 5 - 15% 5 - 8% 0.5 - 6%
• < 1000g 8 - 15% 8 - 15% 4 - 12%
• < 750 - 800g 3 - 14% 3 - 28% 4 - 15%

49. Management
• Multidisciplinary team
– Neonatologists
– Nurses
– Therapists
– Psychologists
– Medical specialists: ophthalmologist,
otolaryngologist, cardiologist, paediatric
surgeon, plastic surgeon
– Medical social worker

51. Extremes of
Birth Weight
Neonatal
Hypoglycaemia
Prematurity