The effect of large doses of synkavit in the newborn.

Experimental work during the years 1929 to 1934 established the fact that a haemorrhagic disease observed in chicks was due to deficiency of a fatsoluble dietary factor: in 1935 Dam proposed the nane vitamin K (Koagulations vitamin) for this factor. Dam, Sch0nheyder and Tage-Hansen in 1936 demonstrated a hypoprothrombinaemia which prolonged the clotting time in vitamin-K-deficient chicks, although vitamin K itself had no thrombinlike activity. In 1935 it was shown that mammals might develop vitamin K deficiency with its associated hypoprothrombinaemia and haemorrhagic tendency. Warner, Brinkhous and Smith described the syndrome in human adults in 1938, relating it to destructive jaundice: meanwhile, haemorrhagic diseas of the newborn with hypoprothrombinaemia had been observed in 1937 by Brinkhous, Smith and Warner. Treatment with vitamin K has now become an established form in haemorrhagic disease of the newborn and its effect on the prothrombin time is widely recognized. Waddell and Guerry found that the period of most marked prothrombin deficiency occurred from 48 to 72 hours after birth, and drew attention to the apparent seasonal variation in prothrombin deficiency, which is most marked in winter and maximal in March judged by the incidence of deaths due to haemorrhagic disease (Waddell and Guerry, 1939a and b; Waddell, Guerry and Birdsong, 1940; Waddell, Guerry, Bray and Kelley, 1939; Waddell and Lawson, 1940). It has become the general practice in maternity units to administer a routine prophylactic dose of vitamin K to all infants at birth.