Blood loss related to participation in pharmacokinetic study in preterm neonates

Neonatology. 2011;100(2):111-5. doi: 10.1159/000323699. Epub 2011 Mar 2.


Background: The amount of blood that can be safely drawn from a preterm neonate for scientific purposes is poorly established.

Objectives: To provide scientific evidence on the amount of blood that can be drawn from very low birth weight (VLBW) neonates for study purposes.

Methods: We performed a post-hoc analysis of a pharmacokinetic (PK) study of penicillin-G, enrolling 18 neonates with a birth weight of <1,200 g, gestational age of <28 weeks and postnatal age of <5 days, with a risk of early onset sepsis. A median of 2.3 ml/kg of blood was collected from each neonate for the PK analysis. Hemoglobin (Hgb), hematocrit (Ht), basic hemodynamic parameters, total fluid intake, number of blood component transfusions and number of blood analysis for clinical indications were recorded. The control group consisted of 35 gestational age-, postnatal age- and birth weight-matched neonates who had not participated in a PK study.

Results: We did not observe significant differences in any studied safety parameter, including Hgb and Ht values, between the two groups. Median number of blood component transfusions (n = 2 in both groups), median volume of transfused red blood cells (22 vs. 24 ml/kg in study vs. control group) and total daily fluid requirement were similar. The median calculated blood loss on clinical indications was 1.9 ml/24 h in the control group and 1.66 ml/24 h in the study group.

Conclusions: In VLBW neonates, up to 2.3 ml/kg of blood (corresponding to 2.4% of calculated circulating blood volume) can be drawn for scientific purposes without compromising basic hemodynamic parameters, Hgb and Ht values, blood component transfusions or fluid requirements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Specimen Collection / adverse effects*
  • Blood Specimen Collection / methods
  • Blood Transfusion
  • Blood Volume*
  • Case-Control Studies
  • Female
  • Hematocrit
  • Hemodynamics / physiology*
  • Hemoglobins / metabolism
  • Humans
  • Infant, Newborn
  • Infant, Premature / blood
  • Infant, Premature / physiology*
  • Infant, Very Low Birth Weight / blood
  • Infant, Very Low Birth Weight / physiology
  • Male
  • Penicillin G / pharmacokinetics*
  • Retrospective Studies


  • Hemoglobins
  • Penicillin G