Hemostasis in vessels of the umbilical cord in premature and extremely premature newborns

Abstract

According to the WHO, about 10% of children are born prematurely every year. The hemostatic system of the fetus and newborn is markedly different from the ones of adults. Physiological concentrations of coagulation proteins gradually increase during pregnancy and are expected lower in preterm infants compared to full-term infants. It’s known today that neonates have a reduction of coagulation factors I-XII (except VIII), the coagulation inhibitors antithrombin III, protein C, and heparin cofactor II at the same time. The tendency to hypocoagulation is more pronounced in premature newborns.

Purpose - to compare the main parameters of hemostasis in full-term and premature newborns in different gestational periods.

Materials and methods. This study has analyzed the level of fibrinogen, D-dimer, prothrombin index, and activated partial thromboplastin time in the blood of mothers and their newborns. The study included three groups of mothers and their newborns: the Group I at 37-41 weeks of gestation, the Group II - 28-34 weeks, the Group III - 22-27 weeks.

Results. The studies have shown that the level of fibrinogen in umbilical cord blood is much lower than in maternal, both in fulltime delivery and in preterm cases of 28-34 weeks and 22-27 weeks. The increase of the D-dimer range comparatively to mother’s is received in all terms and more than double in 22-27 weeks (910±347.6 μg/l in newborn against maternal 487±267.0 μg/l, p<0.05). A fetal prothrombin index level was one and a half more two times smaller in comparison to mothers signs in all cases: 56±9.8% in 35-41 weeks, 53±13.2% in 28-34 weeks and 60±11.7% in 22-27 weeks of gestations. And vice versa, an activated partial thromboplastin time is one and a half more two times higher than all maternal values - 49.7±7.86 sec., 59.4±19.11 sec., and 50.1±22.15 sec. in accordance with terms of gestations with a normal 28-40 sec. in adult.

Conclusions. The blood of newborns in all terms is characterized by a higher level of D-dimer compared to maternal values (970±430.9 μg/l in the term 37-41 weeks, 875±226.1 μg/l in 28-34 weeks, 910±347.6 μg/l in 22-27 weeks). D-dimer concentration ranges in neonates differ from those in adults, so caution is required in their use and interpretation. A higher level of AChT (49.7±7.86 sec; 59.4±19.11 sec; 50.1±22.15 sec, according to groups) and lower fibrinogen values (1840±660.5 mg/l in term 37-41 weeks; 1734±542.6 mg/l in 28-34 weeks; 1498±1005.5 mg/l in 22-27 weeks) and PI (56±9.8%; 53±13.2%; 60±11.7%) compared to their mothers. 2. The level of fibrinogen concentration of full-term newborns (1840±660.5 mg/l) is probably higher, compared to 1498±1005.5 mg/l in the period of 22-27 weeks of gestation (p<0.05), the difference in other indicators of coagulation independently from the gestational age was not statistically significant.

The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies.

No conflict of interests was declared by the authors.