title: Labor does not affect the neonatal absolute nucleated red blood cell count.
abstract: We investigated whether the presence or absence of physiologic labor may affect the neonatal nucleated red blood cell (RBC) count. We compared absolute nucleated RBC counts taken at approximately 6 hours of life in term infants born by elective cesarean delivery without trial of labor ( n = 32) and in vaginally delivered infants ( n = 28). Venous blood samples were analyzed and differential cell counts were performed manually; absolute nucleated RBC were counted and expressed as an absolute number. There were no significant differences between groups in birth weight, gestational age, maternal age, gravidity, parity, maternal analgesia during labor, 1- and 5-minute Apgar scores, and infant sex. There was a significantly higher hematocrit and RBC count in the vaginally delivered group as compared with the cesarean group. The absolute nucleated RBC, corrected leukocyte and lymphocyte, and platelet counts were strikingly similar in both groups. We conclude that labor does not affect the neonatal nucleated RBC count. This finding supports the speculation that physiologic labor does not induce a fetal hypoxemia severe or prolonged enough to produce hematological evidence of increased erythropoiesis.
authors.affiliation: Department of Obstetrics and Gynecology, Lis Maternity Hospital, Tel Aviv, Israel.
authors.forename: Galit
authors.initials: G
authors.lastname: Sheffer-Mimouni
authors.forename: Francis B
authors.initials: FB
authors.lastname: Mimouni
authors.forename: Ronit
authors.initials: R
authors.lastname: Lubetzky
authors.forename: Michael
authors.initials: M
authors.lastname: Kupferminc
authors.forename: Verda
authors.initials: V
authors.lastname: Deutsch
authors.forename: Shaul
authors.initials: S
authors.lastname: Dollberg
mesh_terms: D000328:Adult; D002585:Cesarean Section; D036861:Delivery, Obstetric; D004906:Erythrocyte Count; D005260:Female; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D007743:Labor, Obstetric / Q000502:physiology*; D008297:Male; D011247:Pregnancy; D011446:Prospective Studies