Coagulation studies in very low-birthweight infants.

Reference values for coagulation studies of premature infants (24 to 29 weeks' gestational age) are needed for the management of hemostatic disorders in the precariously ill infant. We collected data on the very low-birthweight infants admitted to our intensive care nursery who met criteria over a 4-year period to determine prothrombin time, activated partial thromboplastin time, and fibrinogen levels in this group. Fifty-two infants had a mean prothrombin time of 14.5 seconds, a mean activated partial thromboplastin time of 69.5 seconds, and a mean fibrinogen level of 1.35 g/L. Converting values to ratios of adult control values facilitated direct comparison of results to published reference ranges. Coagulation studies may vary over a broad range of prematurity, and normal ranges are needed for prospective, randomized protocols designed to prevent the complications of abnormal coagulation function.