prematurity lecture note prepared by abrham tesfaye

1. Prematurity
Abrham T.
(BSc in Mid, MSc in Epi fellow)
7/4/2021 1
Abrham T.

2. Prematurity
Definition (WHO)
• Live born infant delivered before 37 weeks
Classification based on gestational age
 42 weeks and above---post term
 37-42 weeks----term
 34-37 weeks---late preterm
 28-34 weeks---very preterm
 Less than 28 weeks---extremely preterm
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3. Prematurity
Classification based on birth weight
4000 gm and above---Macrosomia
2500----4000 gm ----Normal birth weight
1500- 25000 gm----Low birth weight
1000-1500 gm ---Very low birth weight (VLBW)
< 1000gm --Extremely low birth weight (ELBW)
Classification based on Birth weight and
gestational age comparison
 Large for gestational age (LGA)
 Appropriate for gestational age (AGA)
 Small for gestational age (SGA
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4. Cont…
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• Appropriate for gestational age (AGA) — weight
is appropriate for the gestational age weight is
between 10th and the 90th percentile for the
gestational age
• Small for gestational age (SGA) — smaller than
expected, the weight falls below the 10th percentile
for the gestational age.
• Large for gestational age (LGA) — heavier than
expected, the birth weight is above the 90th percentile
for the gestational age

5. SMALL FOR GESTATIONAL AGE
LARGE FOR GESTATIONAL
AGE---LGA
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6. Prematurity
Epidemiology
• Increasing incidence due to multiple pregnancy
• 10 % of deliveries are premature
• 20-30% of neonatal deaths are due to prematurity
• Death increase as birth weight or GA decrease
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7. Prematurity—fetus in utero
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8. Physical maturity scoring
Parameter Preterm Term Posterm
Skin Red, translucent Peeling Dry , cracked
Ear Soft Firm Recoil
Eye Closed Open Stare
Genitalia-Male No testes, red small
scrotum
Testes in the
scrotum
Dark and pendulus
scrotum
Geintalia-female Visible minora and
clitoris
Majora covering
minora and clitoris
Darker large
majora
Breast None Visible and
palpable
Large areola and
nipple
Plantar crease No visible crease
or only red marks
Single transverse
crease
Several plantar
creases
Lanugos Excess few Bald areas
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9. Prematurity
Causes of prematurity
Fetal causes
• Respiratory distress, congenital anomalies
• Fetal infections, Multiple pregnancy
Maternal causes
• Gestational diabetes, Pre-eclampsia
• Substance abuse, stress, maternal age
• Acute or chronic maternal illness
Placental causes
• PROM, Abruption
• Placenta previa
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10. Physical maturity
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11. Problems of prematurity
CNS: Prinatal asphyxia, Apnea, Intracranial bleeding,
cerebral palsy, mental retardation
Hematology: Anemia, polycythemia, bleeding,
Jaundice
GIT: Necrotizing enterocolitis, Feeding difficulty
Renal: Edema, electrolyte imbalance
RSPS: HMD, Congenital pneumonia, apnea
Immunology: Deficiency of WBC,
Metabolic : Hypoglycemia, Hypothermia
CVS: Hypotension, Patent ductus arteriosus
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12. Characteristics of preterm baby
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• Compared with the term infant, the premature infant
is:
Tiny, scrawny, and red.
The extremities are thin with very little muscle or s/c fat
 Head and abdomen are disproportionately large and the
skin thin, relatively translucent
Usually wrinkled vein of the abdomen and scalp are more
visible
The ears have soft, minimal cartilage, and thus are very
pliable
The soft bones of the skull have a tendency to flatten on
the sides, and the ribs yield with each laboured breath.

13. Cont.
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• Testes are undescended in the
male; labia and clitoris are quite
prominent in the female.
• The soles of the feet and palms of
the hands have few creases
• Many of the typical newborn
reflexes are weak or absent.

14. Cont.
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• In the prone position the premature
infant lies with pelvic flat and leg
spread in a frog like position.
• While term infant lies with limb flexed,
pelvis raised, and knees drawn up
under abdomen
• The premature infant has altered
physiology due to immature and often
poorly developed system:

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• Respiratory muscles are poorly developed, chest wall
lack stability, production of surfactant is reduced,
and breathing may be laboured and irregular with
period of apnoea and cyanosis.
• Infant prone to atelctasis
• Gag and cough reflexes are poor, thus aspirations
are problem
• Stomach is small vomiting is likely to occur
Cont.

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• Have very little subcutaneous fat thus there is no heat storage
or insulation, cannot shiver, has poor vasomotor control of
blood flow to the skin capillaries
• There is relatively high surface area in comparison with
body weight
• Has reduced muscle and fat deposited that restrict metabolic
rate and heat production
• Response to stimuli is low : suck, swallow, gag, and cough
reflexes are poor : feeding and aspirations are also problem
• Actively formed antibodies and IgM are absent at birth
• Liver does not have ability to handle and conjugate bilirubin,
do not release and store glucose well
Cont.

17. Management of prematurity
1. Temperature regulation
Incubator, KMC, radiant heater
2. Maintenance fluid
Slowly increase from 60ml/kg/day---150ml/kg/day
3. Feeding
Gavage feeding (NGT) use breast milk
Expressed breast milk cup feeding
4. Treat sepsis
 Ampicillin + Gentamycin
5. Treat accompanying Complications
HMD, NEC, Hypoglycemia, Jaundice etc
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18. KMC
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19. Post term Neonate
Dry parchment like
skin with peeling
and cracking,
coarse hair, stare
look, long finger
nails and meconium
staining due to
placental
insufficiency
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20. 7/4/2021 Abrham T. 20

21. Thank You!!
7/4/2021 Abrham T. 21