Development of the human coagulation system in the healthy premature infant

This study was designed to determine the postnatal development of the human coagulation system in the healthy premature infant. Consecutive mothers of healthy premature infants born at either St Joseph’s Hospital or McMaster University Medical Centre in Hamilton were asked for consent. One hundred thirty-seven premature infants (30 to 36 weeks of gestational age) entered the study. The premature infants did not have any major health problems and did not require ventilation or supplemental oxygen. Demographic information and a 20-mi blood sample were obtained in the postnatal period on days 1. 5, 30. 90, and 1 80. Between 40 and 96 premature infants were studied on each day for each of the following tests: prothrombin time. activated partial thromboplastin time, thrombin clotting time. plasminogen; 1 3 factor assay