Placing the newborn on the maternal abdomen increases the volume of umbilical cord blood collected C. PAFUMI*, G. ZIZZA*, A. RUSSO*, M. FARINA*, G. PERNICONEà, S. BANDIERAà, P. GIARDINAà, L. MANGIAFICO , R. MANCARI , I. MAGGI*, A.E. CALOGERO§, A. CIANCI* *Department of Microbiological and Gynaecological Sciences,  Haematology, àClinical pathology, §Chair of Endocrinology, Department of Internal Medicine, University of Catania, Italy. Summary Haematopoietic stem cell transplantation is an important therapy for certain haema- tological and malignant disorders. Umbilical cord blood contains a high proportion of potentially transplantable haematopoietic progenitor cells. However, the use of cord blood stem cell transplantation is limited by the low number of stem cells obtainable from a single cord blood donor. The aim of our study was to investigate the possibility that procedures during delivery might in¯uence the number of umbilical cord blood haematopoietic progenitor cells available for transplantation. We assessed the effects of `upper' and `lower' positions of the newborn infant on the yield of cord blood stem cells in 51 vaginal deliveries. Neonates in the `upper position' group were placed by the midwife on the maternal abdomen immediately after birth, while those in the `lower position' group were placed on the delivery table, below the maternal introitus. The total volume of cord blood and the total number of CD34+ cells collected from babies in the upper position group were signi®cantly higher than those from babies in the lower position group. There were no signi®cant differences in cord blood haemoglobin levels and white blood cell counts between the two groups, nor were there any adverse effects in the newborn infants. The simple manoeuvre of placing the newborn on the maternal abdomen after delivery may thus increase the yield of transplantable hae- matopoietic progenitor cells in cord blood. Keywords Delivery, newborn position, umbilical cord blood Introduction The structural and functional integrity of the haemato- poietic system is maintained by CD34+ stem cells, which can self-renew or differentiate, producing cells of var- ious haematopoietic lineages (Morrison & Shah, 1997). Haematopoietic stem cell transplantation is an important therapy for certain haematological and malignant disor- ders (Miniero et al., 1995; Katzenstein et al., 1997; Arcese et al., 1998; Engelfriet et al., 1998). Umbilical cord blood contains a high proportion of potentially transplantable haematopoietic progenitor cells (Rubinstein et al., 1998), with a higher proliferative potential in vitro and in vivo than bone marrow or mobilized peripheral blood stem cells (Bertolini et al., 1998). Accepted for publication 30 August 2001 Correspondence: Professor Carlo Pafumi, Department of Microbio- logical and Gynaecological Sciences, University of Catania, Via G. D'Annunzio 125±95127, Catania, Italy. Tel: + 39 330847191; Fax: + 39 095326628; E-mail: pafumi@mbox.unict.it Clin. Lab. Haem. 2001, 23, 397±399 Ó 2001 Blackwell Science Limited 397