Prothrombin time in first week of life with special reference to vitamin K administration.

Prothrombin time was estimated in 100 neonates (80 full term and 20 preterm). Among the full term infants 50 were healthy and 30 sick. Prothrombin time was altered in neonates with birth hypoxia and prematurity (p less than 0.001). Vitamin K administration to anoxic babies resulted in improvement in prothrombin time after 48-72 hours (p less than 0.001). Four newborns has bleeding, 2 had anoxia and 2 were only in preterms who did not receive vitamin K after birth. It is concluded that vitamin K should be given to all preterms and those with difficult deliveries; term, healthy newborns do not need it.