post-term infant
Newborn delivered at or after 42 weeks 0 days (294 days) of completed gestational age, associated with increased perinatal risks.
Full Definition
A post-term infant is born at 42 weeks of gestational age or later, representing approximately 3-12% of all pregnancies depending on the population studied. Post-term pregnancy is associated with increased risks including fetal macrosomia, oligohydramnios, meconium-stained amniotic fluid, birth trauma, and perinatal asphyxia. These infants may show signs of post-maturity syndrome, including decreased subcutaneous fat, dry and peeling skin, long nails, and abundant hair. The placenta may show signs of aging with decreased function, leading to inadequate oxygen and nutrient delivery. Post-term infants require careful monitoring for complications and may need more intensive initial care despite their mature gestational age.
Usage
Usage note: Preferred term over 'post-mature' or 'overdue' in clinical documentation.
In Context
- "The post-term infant showed signs of post-maturity with dry, peeling skin and decreased vernix." — Physical examination
- "Post-term infants have increased risk of meconium aspiration and birth trauma due to their size and prolonged gestation." — Clinical guidelines