THE CONTEXT
Gestational age can be assessed from pregnancy information and newborn maturity examination. Neonatal vital parameters require interpretation alongside sleep, breathing patterns and circulation.
Gestational age and maturity
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The stated gestational categories are preterm at less than 37 weeks, term at 37–41 weeks, and post-term at more than 42 weeks.
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Assessment uses a reliably known last menstrual period when periods have been regular, first-trimester ultrasound, or newborn examination.
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Newborn maturity examination assesses physical features and neurological maturity.
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Expanded New Ballard Scores provide gestational age with an accuracy of 1 week.
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The accompanying caption describes an IUGR neonate with wrinkled skin and peeling.
Heart rate and temperature
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Normal heart rate is 100–160 beats per minute in term neonates and 120–180 beats per minute in preterm neonates.
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A heart rate as low as 80 beats per minute can be normal during sleep in term neonates.
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Tachycardia suggests sepsis, anemia, fever or congestive cardiac failure.
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Normal axillary temperature is 36.5–37.4°C. Axillary temperature is a good proxy for core temperature, and rectal temperature measurement is unnecessary.
Capillary refill and breathing
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Normal capillary refill time is 3 seconds or less. A longer time suggests poor circulation, as in shock or hypothermia.
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Assess capillary refill over the sternum by pressing with the ball of a finger or thumb for 5 seconds and then timing refill.
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Normal respiratory rate is 40–60 breaths per minute. Repeat a borderline count approaching 60.
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Periodic breathing with short apneic pauses lasting 5–10 seconds is normal. Apnea accompanied by cyanosis or bradycardia is abnormal.