Three out of four newborn infants (premature twins, one case of prolonged delivery and one case of relapsing respiratory arrest) showed microthrombi in the vessels of the extremities as morphological symptoms of a generalized plasmatic hypercoagulability, consumption of clotting factors, and disseminated intravaseular coagulation which takes place in the newborns during birth and during the perinatal period. The thrombi in the extremities are regarded as clinical manifestation of a generalized microthrombosis which involves the vascular system of many organs, i.e. liver, lungs, spleen, intestine, suprarenal glands, and kidneys.Fibrin-rich intravascular microthrombi in the vessels of the extremities are considered as morphological equivalents of a generalized hypereoagulability and subsequent disseminated intravascular coagulation. They are already initiated in utero following intra-uterine asphyxia with hypoxemia and acidosis in the capillary microcireulation (inadequate capillary perfusion).Disseminated intravascular coagulation can also occur in the immediate perinatal period due to a generalized hypercoagulability of the plasma, which had been initiated in utero and persisted during the perinatal time without having been already converted in utero into a disseminated intravascular microthrombosis. Hypercoagulability can be perpetuated and intensified by a membrane syndrome in newborn infants with respiratory distress syndrome.The pathogenetic relations between hypoxemia and acidosis in the microcirculation of nascituri and newborns, hypercoagulability of plasma with thrombocytopeuia and with consumption of clotting factors in utero, hemorrhagic diathesis during birth, disseminated intravascular coagulation in stillbirths and in newborn infants, and the respiratory distress syndrome with hyaline membranes of the lung are discussed.
