Increased concentrations of D-dimers in newborn infants.

Abstract

The concentrations of D-dimers (the D fragments of fibrinogen) were measured in blood from 15 preterm infants, and 45 born at fuli term, to establish normal ranges. The adult normal range is <0 25 mg/l; 31 of the 60 infants (52%) had values <0*25 mg/l, in 16 (27%) they were 0-25-0-5, in eight (13%) 0-5-1, in three (5%) 1-2, and in two (3%) 2-4. D-dimer concentrations measured during the neonatal period should be interpreted with caution.D-dimers (D fragments of fibrinogen) are produced during plasmin mediated lysis of fibrin.' They are more specific than fibrin/fibrinogen degradation products, which are formed during degradation of fibrinogen and fibrin.2 D-dimers can be measured using 10 1d of plasma in five minutes from specimens taken in EDTA, heparin, or citrate by a latex agglutination technique.3In adults the concentration of D-dimers is the most sensitive marker for monitoring the activity of disseminated intravascular coagulation,3 and the adult normal range is less than 0-25 mg/1.4 The aim of this study was to evaluate the test in newborn infants and to find out whether pregnant women had significantly increased values before delivery that might affect the concentrations in their infants. Patients and methods Full blood counts, coagulation screens, and D-dimers were measured in samples of venous blood taken from 15 preterm infants and 45 born at full term. The gestational ages of the preterm infants were: 27-28 weeks (n= 1), 29-30 weeks (n=l), 31-32 weeks (n=10), and 33-34 weeks (n= 3). The preterm infants had no serious complications of prematurity, although two received short periods of ventilation (less than 24 hours); this is our routine for infants of less than 30 weeks' gestational age. All infants received vitamin K 1 mg at birth by intramuscular injection.

High-Dose Urokinase Therapy in Newborn Infants with Major Vessel Thrombosis

“…30 Also, D-dimer concentrations may be elevated during active thrombosis. In one of our patients, the D-dimer concentration was elevated prior to therapy but became unmeasurable during UK perience with the use of tissue plasminogen activator.34 It is possible that individually adjusted thrombolytic therapy may be more effective than fixed-dose regimens and that high doses of UK or other fibrinolytic agents may be needed in some infants.…”

Neonatal coagulation problems

“…Similarly, there are no reliable normal ranges for D-dimers, and there is limited evidence to suggest that baseline concentrations may be higher during the neonatal period. 19 In addition, fibrinogen concentrations normally increase slightly during the first few days of life and may initially be preserved. Early diagnosis of this condition is likely to be increasingly important in order to target management, and, with this in mind, scoring systems have been developed for use in adults, which may help to predict early non-overt DIC.…”

The investigation and management of neonatal haemostasis and thrombosis*

“…d ‐dimer estimation is a specific test of fibrin lysis by plasmin and is a sensitive marker of coagulation activation, including disseminated intravascular coagulation. There are very few data on normal d ‐dimer levels in the neonate, but these have been reported to be increased in cord blood samples even in the absence of DIC because of the activation of coagulation which occurs during delivery (Hudson et al , 1990).…”