Effect of freezing plasma at -20°C for 2 weeks on prothrombin time, activated partial thromboplastin time, dilute Russell viper venom time, activated protein C resistance, and D-dimer levels.

To assess the impact of preanalytical variables of time and temperature on prothrombin time (PT), activated partial thromboplastin time (aPTT), dilute Russell viper venom time (DRVVT), activated protein C resistance (APCR), and d-dimer, samples from 23 healthy individuals and 18 patients having coagulopathy with known abnormal PT and aPTT were collected. Plasma from each individual was separately pooled and aliquoted; the first 2 aliquots were stored at room temperature then analyzed at 2 hours (baseline) and 4 hours postcollection. The remaining aliquots were stored at -20°C and thawed for analysis at 48 hours, 1, and 2 weeks.

Infants born before 29 weeks gestation: survival and morbidity at 2 years of age.

In a collaborative study involving two hospitals with large maternity services, 166 liveborn infants of gestational age from 24 to 28 weeks were born in the calendar years 1977 and 1978. Of these infants, 75 (45.2%) died either in hospital or after discharge home.