Last updated:
March 31, 2026
Overview
Prematurity is defined as birth before 37 completed weeks of gestation
Classification of prematurity
| Gestational age | Prematurity |
|---|---|
| 32 – 37 weeks | Late preterm |
| 28 – 32 weeks | Very preterm |
| < 28 weeks | Extremely preterm |
Predisposing Factors
- Maternal factors
- Pre-eclampsia
- Chorioamnionitis
- Gestational diabetes mellitus
- Previous preterm babies
- Poor socioeconomic status
- Fetal factors
- Congenital infections
- Multiple pregnancy
- Obstetric factors
- Preterm rupture of membranes
- Uterine and cervical malformations
- Placental pathology
- Polyhydramnios
Clinical Presentation
Gestational age is best approximated using the New Ballard Score.
- Birth weight <2.5kg
- Birth length < 47cm
- Head circumference <33cm
- Chest circumference <30cm
- Skin
- Thin, pink, very little subcutaneous fat
- Lanugo hair
- Nails don’t reach fingertips
- Ear – soft and shapeless due to little cartilage
- Breast nodule – little to no breast tissue with the areola barely visible
- Genitalia
- Female – prominent labia minora and clitoris
- Male – smooth scrotum with undescended testes
- Soles
- Only the anterior crease is present
- Creases don’t reach two-thirds of the sole
- Activity
- Weak cry
- Weak movement
- Hypotonia
- Sucking and swallowing are uncoordinated
Comparison between a preterm and a term infant
| 23 – 24 weeks gestation age | 37 – 42 weeks gestation age | |
|---|---|---|
| Birthweight (50th centile) | Male 700 g and female 620 g at 24 weeks | Male 3500 g and femal 3400 g at 40 weeks |
| Skin | Thin, dark red colour all over the body | Thick, pale pink colour |
| Ears | Pinna is soft and no recoil | Pinna is firm, has cartilage to the edge, and has immeidate recoil |
| Breast tissue | None palpable | One or both nodules > 1 cm |
| Male genitalia | Smooth scrotum, no testes in scrotum | Scrotum with rugae, testes in scrotum |
| Female genitalia | Prominent cltoris, labia majora widely separated, labia minora protruding | Labia minora and clitoris covered |
| Breathing | Apnoea is common. Needs respiratory support | Apnoea is rare, Rarely needs respiratory support |
| Sucking and swallowing | No coordinated sucking | Coordinated from 34 – 35 weeks |
| Feeding | Needs parenteral nutrition and tube feeding | Cries when hungry. Feeds on demand |
| Cry | Faint | Loud |
| Vision | Eyelids fused, infrequent eye movements | Makes eye contact. Alert wakefullness |
| Hearing | Startles to loud noise | Responds to sound |
| Posture | Limbs extended, jerky movements | Flexed posture, smooth movements |
Complications
- Respiratory
- Respiratory distress syndrome
- Apnoea of prematurity
- Congenital pneumonia
- Bronchopulmonary dysplasia
- Pneumothorax
- Cardiovascular
- Patent ductus arteriosus
- Hypotension due to hypovolemia and cardiac dysfunction
- Bradycardia due to apnoea
- Central nervous system
- Acute and chronic bilirubin encephalopathy due to an immature blood-brain barrier
- Intraventricular haemorrhage and periventricular leukomalacia
- Hypoxic-ischemic encephalopathy
- Gastrointestinal system
- Necrotising enterocolitis
- Inguinal hernias (due to patent foramen ovale)
- Hematological
- Immunological
- Increased risk of infection due to an immature immune system
- Nutritional and metabolic
- Osteopaenia of prematurity
- Rickets
- Hypoglycemia due to insufficient glycogen stores
- Hypocalcemia
- Other electrolyte imbalances
- Poor weight gain due to weak suckling and swallowing; poor digestion and absorption
- Hypothermia
- Large surface area to body weight ratio, causing excessive heat loss
- Reduced subcutaneous fat stores
- Immature heat regulation centre
- Ophthalmology
- Retinopathy of prematurity
- Others
- Jaundice
Management
Antenatal care
- Avoid maternal smoking, irradiation & drugs
- Assessment of the foetus by ultrasound
- IM Steroids if <34 weeks
- In special situations, amniocentesis or foetal blood sampling may be indicated.
Immediate post-natal care
- Place the baby under the radiant warmer
- Drying of the baby & suction of secretions
- APGAR scoring & resuscitation if needed
- Complete examination of the newborn
- Care of the skin and aseptic cutting of the umbilical cord
- Vitamin K (1 mg IM) is given for all neonates (0.5 mg IM is < 1500 g).
If the baby is large and premature (> 2 kg) with no critical illness, they can be discharged
If the baby is< 2 kg in weight or has a critical illness, they require incubator care
Incubator care
- Temperature – Is adjusted to keep body temperature 36.5-37.2 °C
- Humidity – Kept around 40-60%
- Oxygen therapy – Given in the lowest concentration for the shortest period with gradual withdrawal
- Prevention of infection
- All medical personnel must wash their hands before and after examining the baby
- No person with an infection should be admitted into the nursery
- Antibiotic administration is indicated
- Adequate feeds and fluids (follow protocol)
- Treatment of associations, e.g. Phototherapy for hyperbilirubinaemia
Discharge criteria
Discharge from the incubator if:
- Infant > 1750 grams with good suckling
- Can maintain temperature outside the incubator
- No critical illness
- Normal respiration
Instructions to the parents
- Maintain body temperature
- Keep the infant away from infection by minimising handling and overcrowding
- Schedule for feeding
- Schedule for vaccination
- Encourage follow-up visits
- Ophthalmic examination for those exposed to prolonged oxygen therapy