Neonatal Nucleated Red Blood Cells in Discordant Twins

The objective of this study was to test the hypothesis that in discordant twins, the smaller infant has higher absolute nucleated red blood cell (RBC) count than the larger sibling. We compared absolute nucleated RBC counts, hematocrits, absolute leukocyte counts, absolute granulocyte counts, absolute lymphocyte counts, RBC counts and platelet counts obtained in the first 12 hours of life in 30 discordant twin sets. The smaller infant had a higher absolute nucleated red blood cell count and lower platelet counts than its larger sibling. Platelet counts correlated inversely with absolute nucleated RBC counts (R ² = 24.5%; p < 0.001) and absolute nucleated RBCs correlated directly with percent intertwin weight differences (R ² = 17.8%; p = 0.02). In discordant twins, the smaller infant has higher absolute nucleated RBC count and lower platelet counts than the larger sibling. We speculate that the hematologic alterations in the smaller fetus are linked to relative fetal hypoxia.

Nucleated red blood cells - erythropoiesis - discordant - intrauterine growth - twins - hypoxia

REFERENCES

• 1 Shuper A, Mimouni F, Merlob P, Zaizov R, Reisner S H. Thrombocytopenia in small-for-gestational age infants.  Acta Paediatr Scand. 1983;  72 139-140
• 2 Humbert J R, Abelson H, Hathaway W E, Battaglia F C. Polycythemia in small for gestational age infants.  J Pediatr. 1969;  75 812-819
• 3 Meberg A, Orstavik I, Sovde A. Erythroblastemia and thrombocytopenia in small for gestational age infants. Relation to intrauterine hypoxia, infections, and maternal smoking.  Acta Paediatr Belg. 1978;  31 213-218
• 4 Mori H, Mori K, Kojima Y et al.. Neonatal nucleated red blood cell counts in twins.  J Perinat Med. 2001;  29 144-150
• 5 Creasey RK, Resnik R Maternal-Fetal Medicine: Principles and Practice. 2nd ed. Philadelphia; WB Saunders 1989: 1162-1163
• 6 Ballard J L, Khoury J C, Wedig K, Wang L, Eilers-Walsman B L, Lipp R. New Ballard Score, expanded to include extremely premature infants.  J Pediatr. 1991;  119 417-423
• 7 Lubchenco L O, Hansman C, Boyd E. Intrauterine growth in length and head circumference as estimated from live births at gestational ages from 26 to 42 weeks.  Pediatrics. 1966;  37 403-408
• 8 Snijders R JM, Abbas A, Melby O, Ireland R M, Nicolaides K H. Fetal plasma erythropoietin concentration in severe growth retardation.  Am J Obstet Gynecol. 1993;  168 615-619
• 9 Dollberg S, Fainaru O, Mimouni F B, Shenhav M, Lessing J B, Kupferminc M. Effect of passive smoking in pregnancy on neonatal nucleated red blood cells.  Pediatrics. 2000;  106 E34
• 10 Philip A GS, Tito A. Increased nucleated red blood cell counts in small for gestational age infants with very low birthweight.  Am J Dis Child. 1989;  143 164-169
• 11 Cassady G. Plasma volume studies in low birth weight infants.  Pediatrics. 1966;  38 1020-1027
• 12 Soothill P W, Nicolaides K H, Campbell S. Prenatal asphyxia, hyperlacticaemia, hypoglycaemia, and erythroblastosis in growth retarded fetuses.  BMJ. 1987;  294 1051-1053
• 13 Oski F A, Naiman J L. Hematologic problems in the newborn. Philadelphia; WB Saunders 1982: 1-31
• 14 Harris P F, Harris R S, Kugler J H. Studies of the leukocyte compartment in the guinea-pig bone marrow after acute hemorrhage and severe hypoxia: evidence for a common stem-cell.  Br J Haematol. 1966;  12 419-432
• 15 Jackson C W, Edwards C C. Biphasic thrombopoietic response to severe hypobaric hypoxia.  Br J Haematol. 1977;  35 233-244
• 16 Langdon J R, McDonald T P. Effects of chronic hypoxia on platelet production in mice.  Exp Hematol. 1977;  5 191-198
• 17 McDonald T P. Platelet production in hypoxic and RBC-transfused mice.  Scand J Haematol. 1978;  20 213-220
• 18 Christensen R D, Koenig J M, Viskochil D H, Rothstein G. Down-modulation of neutrophil production by erythropoietin in human erythropoietic clones.  Blood. 1989;  74 817-822