Scar formation after skin injury to the human foetus in utero or the premature neonate

A macroscopically visible scar was present at birth in three infants with a history of injury during amniocentesis at 16–20 weeks’ gestation. In several neonates born between 21 and 31 weeks’ gestation, chemical injury to the skin caused by extravasation of calcium gluconate healed by formation of a large scar. In the infant born at 21 weeks, biopsy of the injured area showed infiltration by large numbers of neutrophils and macrophages. It appears that a very immature neonate can mount a prominent inflammatory reaction and that both a midtrimester foetus and a very immature neonate heal injuries to the skin by scar formation and not by scarless healing.