Intrauterine wound healing in a 20 week human fetus.

Limb amputations, probably caused by amniotic constriction bands, were examined histologically in a 20 week human fetus to assess the degree of intrauterine healing. No acute inflammatory process, no removal of necrotic material, and no granulation tissue formation were seen at any of the amputation sites. A recent ulcer, probably caused by friction of an exposed piece of bone in the stump of the right leg, also showed no inflammatory response. Healing was by coagulation of exposed tissue and by a minor degree of mesenchymal proliferation without repair. Similar changes have been described in experimental intrauterine wound healing in rats, lambs, opossums and baboons. Conversion from a non-specific to a classical postnatal inflammatory response occurs sometime before term. It is not known at what point this change takes place in man; examination of this infant suggests that it occurs after the twentieth week of gestation.