Late-preterm infant: risks and corrected-age follow-up — formative SAQs

SAQ 1 (10)

A 35-week infant is on the postnatal ward at 24 hours of age. He is breastfeeding but tiring quickly, has lost 6 per cent of birthweight, his axillary temperature is 36.3 degrees Celsius in an open cot, and his total serum bilirubin is approaching the gestational-age-specific phototherapy threshold. The parents are keen to go home. ^[1]

1. Define the late-preterm band and explain why this infant is NOT a term infant despite looking mature. (2) ^{[1] [6]}
2. List the discharge-readiness criteria that must ALL be met before this infant goes home, and identify which are currently unmet. (4) ^{[1] [10]}
3. Outline your management of the bilirubin in this infant and justify why the same value is higher-risk than in a full-term infant. (2) ^[9]
4. Describe the corrected-age follow-up plan you will arrange, including timing of the first review and duration of correction. (2) ^[8]

Model answer

Definition and the almost-term trap. Late preterm is 34+0 to 36+6 completed weeks. This 35-week infant is late-preterm — the largest preterm subgroup — and, despite looking mature, carries neonatal mortality around three times and readmission two to three times that of full-term infants because of multi-organ immaturity. "Near-term" is a misnomer that invites harmful complacency. ^{[1] [6]}

Discharge gate and gaps. All of the following must be met: thermal stability in an open cot (axillary 36.5 to 37.5 degrees Celsius), feeding competence with sustained weight gain, glucose stability off supplements, no significant apnoea for five to seven days, bilirubin well below threshold and falling, and family readiness plus a follow-up booked within 48 to 72 hours. Currently unmet: temperature (36.3, cold), feeding (tiring, 6 per cent loss), and bilirubin (approaching threshold). He is not ready for discharge. ^{[1] [10]}

Bilirubin management and risk. Interpret the value against gestational-age-specific thresholds and start phototherapy if at or above the threshold, with repeat measurements to confirm a falling trend. The same bilirubin value is higher-risk at 35 weeks than at term because of immature glucuronyl transferase conjugation, lower albumin binding capacity and a less mature blood-brain barrier. ^[9]

Follow-up plan. Book the first review within 48 to 72 hours of discharge with weight, feeding, jaundice and wellbeing assessment; then review at two weeks, four months, eight to twelve months, eighteen to twenty-four months and four to five years. Correct for the five weeks born early and continue correcting until at least two years; plot on Fenton charts to 50 weeks postmenstrual age then WHO or INTERGROWTH-21st standards. ^[8]