Late preterm infant: risks and follow-up

Overview & Definition

Picture the 35-week baby on the postnatal ward — plump, pink, eyes open, breastfeeding by the clock — the very picture of a healthy newborn. Within twenty-four hours the bilirubin is climbing, the glucose is dipping, the temperature is drifting down and the mother is exhausted. This is the late-preterm paradox: a baby who looks term and behaves preterm. Recognising that paradox is the single most important cognitive step in caring for this group, and it is the question examiners return to again and again. ^{[1] [2]}

A late-preterm infant is defined by gestational age at birth of 34+0 to 36+6 completed weeks. The group is sometimes called "near-term" or "moderate-late preterm", but the term late-preterm is now preferred because "near-term" falsely implies maturity — it invites exactly the complacency that causes harm. Late-preterm infants are the largest preterm subgroup by absolute number, accounting for roughly seventy per cent of all preterm births and around nine per cent of all live births in high-income settings. ^{[1] [6]}

Late preterm is distinct from early term (37+0 to 38+6), which the Defining Term Pregnancy Workgroup carved out as its own higher-risk band within term, and from moderately preterm (32+0 to 33+6). These distinctions are not pedantry — each week closer to full term reduces risk, but the late-preterm band remains a high-risk population whose care and follow-up must be planned, not assumed. ^[6]

References11ShowHide

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