Prematurity
and it’s complications

Introduction
 Definition
 Incidence
 Appropriate birth weight at different gestational ages
 Etiology

Definition
 It is defined as live born infant delivered before 37
weeks from the first day of the last menstrual period.

Incidence
 The exact incidence in Pakistan is not known.
 Estimated 11-13%
 It includes both small for gestational age (SGA) and
appropriate for gestational age (AGA)

Appropriate birth weight at different
gestational ages
Gestational age Mean birth weight
24 weeks 600 g
25 weeks 750 g
26 weeks 850 g
28 weeks 1000 g
30 weeks 1400 g
32 weeks 1750 g
34 weeks 2000 g
36 weeks 2500 g
38 weeks 3000 g
40 weeks 3500 g

Scenario 1
 2days old female born at 28 weeks of gestation with
birth weight of 800 g
 What can be the probable causes of this preterm
birth?

Etiology
 Maternal causes
 Uterine causes
 Fetal causes
 Others

Maternal causes
 Malnutrition and anemia
 Teenage pregnancy or multi-parity
 Twin pregnancy
 Pre eclmapsia
 Chronic illness (diabetes, renal disease, heart
disease, hypertension)
 Infection (malaria, UTI, chorioamnionitis)
 Lower socioeconomic status
 Smoking or drug abuse
 Illegitimate birth

Uterine causes
 Bicornuate uterus
 Incompetent cervix (premature dilation)
 Placenta previa, abruptio placentae, placental
dysfunction

Fetal causes
 Fetal distress
 Multiple gestation
 Chromosomal disorders (down’s syndrome)
 Intrauterine infections (syphilis, TORCH)
 Erythroblastosis, non immune hydrops

Others
 Polyhydramnios
 Trauma
 Premature rupture of membranes
 Iatrogenic

Scenario 2
 1 hour old male neonate born at 25 weeks of
gestation due to abruptio placenta
 Birth weight of 575 g
 APGAR score: 6
1. Blue extremities
2. Pulse 102
3. Feeble cry at stimulation
4. Some flexion
5. Weak irregular breathing
 What can be the complications faced by this
neonate?

Problems/complications of prematurity
 Immediate
 Long term

Immediate (acute) problems
1. Hypothermia
2. Hypoglycemia
3. Hypocalcemia
4. Respiratory difficulties
5. Intra-ventricular hemorrhage (IVH)
6. Liver immaturity
7. Increased susceptibility to infections
8. Necrotizing enterocolitis (NEC)
9. Patent ductus arteriosus
10. Feeding problems
11. Anemia of prematurity
12. Retinopathy of prematurity
13. Metabolic bone diseases of prematurity

Hypothermia
It occurs in preterm babies due to:
 High surface area to body weight ratio
 Little subcutaneous fat
 Muscular inactivity
 Inadequate sweating mechanism
 Decreased brown fat
 Immature heat regulation mechanism

Hypoglycemia
 It is common due to lack f glycogen stores and
immature hepatic and autonomic responses

Hypocalcemia
 Early hypocalcemia occurs due to immaturity of
hormonal control system

Respiratory difficulties
 Hyaline membrane disease due to surfactant
deficiency leading to IRDS
 Apneic spells: the immaturity of respiratory centre
may lead to periodic breathing and frequent apneic
apells

Intra-ventricular hemorrhage (IVH)
It is common in preterm infants due to:
 Immature vasculature
 Disturbed cerebral auto-regulation of blood flow
 Clotting factor deficiency

Liver immaturity
 It results in prolonged physiological jaundice due to
immaturity of liver enzymes and there is increased
risk of kernicterus at relatively lower bilirubin level

Increased susceptibility to infections
 It results from lack of the protective maternal
immunoglobulins (IgG), which are transferred across
the placenta during the last trimester
 In addition to this, delicate surfaces of skin and
mucous membranes also predispose to infections
 Insertion of IV cannula, endotracheal tubes,
nasogastric tubes also increase the risk of infections

Necrotizing enterocolitis (NEC)
 There is increased susceptibility to NEC due to
immaturity of gut endothelial surfaces and enzyme
deficiencies
 The risk increases with lack of breast feeding,
umbilical catheterization and septicemia

Patent ductus arteriosus (PDA)
 The duct may remain open in premature babies
leading to heart failure

Feeding problems
 These result from uncoordinated sucking and
swallowing and also from gastro-esophageal reflux
leading to frequent aspirations

Anemia of prematurity
 Anemia occurs due to decreased iron stores, vitamin
E deficiency and exaggerated physiological anemia

Retinopathy of prematurity
 There is abnormal vascularization due to immaturity
and oxygen therapy leading to partial or complete
blindness

Metabolic bone disease of prematurity
 There is a lack of substrate (calcium and phosphate)
and vitamin D deficiency resulting in rickets

Long term problems
 Chronic lung disease (bronchopulmonary dysplasia)
 Poor growth
 CNS dysfunctions

Chronic lung disease (bronchopulmonary
dysplasia)
 Prolonged ventilation and oxygen toxicity results in
chronic oxygen dependency

Poor growth
 Growth is restricted due to feeding problems, vitamin
and iron deficiency

CNS dysfunctions
 Cerebral palsy due to intraventricular hemorrhage
 Post hemorrhagic hydrocephalus
 Learning problems
 Deafness
 Mental subnormality

Assessment of gestational age
 Gestational age can be assessed appropriately in
weeks by simple visual assessment of certain
physical signs and more accurately by using Ballard
scoring system

Rapid visual assessment of gestational age
Physical signs Assessment Gestational age
Sole creases Absent 32 wks or less
1-2 anterior sole 36 weeks
All over sole 40 weeks
Breast nodule Not palpable 34 weeks
3 mm 36 weeks
4-10 mm 40 weeks
Scalp hair Short fuzzy 37 weeks
Coarse, individual 40 weeks
Ear cartilage Poorly developed 32-34 weeks
Well developed 36-40 weeks
Testicular descent Un-descended 25 weeks
Inguinal region 32 weeks
Completer descent 40 weeks in 90%
Scrotal rugae Anterior 36 weeks
Entire scrotum 40 weeks

Ballard score
 Physical and neuromuscular criteria of maturity are
given in Expanded New Ballard score (NBS). It now
also includes extremely premature infants and has
been refined to improve accuracy in more mature
infants
 In Ballard score, physical and neurologic scores are
added and by this added score, gestational age is
calculated
 The score is accurate within 2 weeks of gestation in
infants weighing >999 g at birth and is most accurate
at 30-42 hours of age

Management
 The management of preterm baby is based upon the
proper anticipation and prevention of complications

Delivery room care
 Every preterm delivery should be attended by a
pediatrician
 Proper resuscitation at birth, early stabilization of
vital signs, prevention of hypothermia and
hypoglycemia in delivery room is related with good
outcomes with minimal complications

 If baby is of good size and vigorous, then by simply
cleaning airways, wrap the baby properly and shift
to well baby nursery with instructions of early
feeding and monitoring for hypoglycemia and
hypothermia
 If baby weight is very low < 1kg, then electively
incubate the baby and shift to NICU for ventilator
care
 Babies weighing 1-1.5kg should also be shifted to
NICU for observation and management of potential
problems

After birth care
 Maintain thermo-neutral environment
 Maintenance of fluid and electrolyte balance
 Oxygen administration
 Feeding
 Supplementation of iron and vitamins
 Protection from infection
 Early detection and management of complications of
prematurity
 Immaturity of drug metabolism

Maintain thermo-neutral environment
 It is environmental temperature at which heat
production and O2 consumption is minimal yet the
core temperature is maintained within normal range
 Maintain temperature of nursery in range of 25-
30°C
 Place the baby in incubator, keep humidity at 70%

 Temperature of incubator varies with age by setting
air temperature or by setting skin temperature of
baby
 Temperature can be maintained by the use of
radiant heaters by wrapping the baby properly and
by the use of mitten on hands and socks on feet and
cap on head if nursed in cot
Weight Temperature
> 2 kg 31-33˚ C
1.5-2.0 kg 32-34° C
1.0-1.5 kg 32-35˚ C
< 1 kg 35-37° C

Maintenance of fluid and
electrolyte balance
 Preterm babies need more fluids as compared to full
term infants
 Baby should be carefully monitored for
hypoglycemia, hypo or hyper-natremia and hyper-
kalemia by frequent blood samples and their
correction
Fluid requirement of premature baby
1st day 60-80 ml/kg/day
2nd day 80-100 ml/kg/day
3rd day 100-110 ml/kg/day
4th day 120-130 ml/kg/day
5th day and onwards 150-160 ml/kg/day

Oxygen administration
 O2 administration should be carefully monitored in a
very premature infant because concentration of O2
more than 40% increases the risk of lung and visual
toxicity (bronchopulmonary dysplasia and retrolental
fibroplasia)

Feeding
 The method of feeding should be individualized as it
varies with weight and gestational age of infant
 The process of oral feeding in addition to sucking
requires coordination of swallowing, epiglottic
closure of larynx, normal esophageal motility, a
synchronized process which is usually absent prior
to 34 weeks of gestation

 If the infant is more than 35 wk gestation, weighing
> 2kg and there is no contraindication of feeding like
persistent vomiting, RDS, sepsis, seizures etc; he
should be started on oral feeding preferably by
breast milk or infant formula with bottle or cup and
spoon
 If baby cannot suck and general condition is better,
tube feeding is preferred
 If very sick or premature, then total or partial
parenteral nutrition is the choice

Supplementation of iron and vitamins
 Every preterm infant should receive supplement
vitamins in addition to breast milk until full mixed
feeding is established or weight is more than 2250
gm
 All preterm babies should receive vitamin K
prophylaxis 1 mg at birth
 Requirement of vitamin A, D, B6 and C is fulfilled by
simply prescribing 0.6ml Vidaylin drops per oral

 Iron supplementation should be started at the age
of 4-8 weeks at dose of 2mg/kg/day
 Before this age it is not well absorbed and also
increases the risk of gastrointestinal infection and
also predisposes to vitamin E deficient hemolysis

Protection from infection
 Proper antiseptic measures should be taken in
maintenance of nursery, incubator and other
equipment and in addition proper hand washing,
cleansing of preterm baby, proper cord care are very
important
 All procedures in nursery should be done with strict
aseptic measures

Early detection and management of
complications of prematurity
 It can be done by good nursery care, monitoring of
heart rate, respiratory rate, temperature, blood
pressure, activity, daily weight and intake and output
record
 Oxygen saturation monitoring is very important in
care of preterm babies

Immaturity of drug metabolism
 Due to renal and hepatic immaturity and diminished
renal and hepatic clearance of almost all drugs,
intervals between doses should be extended

Prognosis
 It is related to gestation and birth weight
 With new advancement in neonatal intensive care in
developed countries, the survival rate for 24 wk
gestation is 25%. But still there is marked disability in
survivors
 5-10% of babies with birth weight less than 1500 gm
have major handicap such as cerebral palsy,
developmental delay, blindness or deafness
 Risk increases with decreasing gestational age and
weight

Discharge criteria for preterm
 A premature infant should be taking feed by nipple
(either bottle or breast feed)
 Baby should be gaining weight properly (10-30
g/day)
 Temperature should be stabilized in an open cot
 There should be no recent episode of apnea or
bradycardia
 There should be no parenteral drug administration, it
may be converted to oral dosing

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