Original Article	Neuropediatrics 2004; 35: 321-324 DOI: 10.1055/s-2004-830365
Georg Thieme Verlag KG Stuttgart · New York
Fetal Cells in Maternal Blood: A Six-Fold Increase in Women who have Undergone Amniocentesis and Carry a Fetus with Down Syndrome: A Multicenter Study
E. Falcidia1[*], E. Parano2[*], A. Grillo3, P. Pavone4, H. Takabayashi5, R. R. Trifiletti6, P. Scollo7, B. Dallapiccola8, P. Grammatico8, A. Novelli9, D. Paladini10, G. Monni11, A. Gulisano12, G. Scassellati13
1 Fertilia, Human Reproduction Medicine Unit, Catania, Italy 2 Institute of Neurological Science, The National Research Council of Italy, CNR, Catania, Italy 3 Labogen, Human Genetic Laboratory, Catania, Italy 4 Department of Pediatrics, University of Catania, Italy 5 Division of Human Genetics, Medical Research Institute, Kanazawa Medical University, Ishikawa, Japan 6 Department of Neurology and Neuroscience, UMDNJ, Newark, NJ, USA 7 Department of Obstetrics and Gynecology, Cannizzaro Hospital, Catania, Italy 8 Department of Experimental Medicine and Pathology, Medical Genetics, University La Sapienza, and IRCCS - CSS San Giovanni Rotondo and CSS Mendel, Rome, Italy 9 IRCCS - CSS San Giovanni Rotondo and CSS Mendel, Rome, Italy 10 Prenatal Diagnosis Unit, Department of Obstetrics and Gynecology, University Federico II, Naples, Italy 11 Microcitemic Hospital, Prenatal Diagnosis Unit, Cagliari, Italy 12 Department of Obstetrics and Gynecology, University of Catania, Italy 13 Obstetrics and Gynecology Unit, San Camillo-Forlanini Hospital, Rome, Italy

Abstract

Fetal nucleated red blood cells (FNRBCs) circulate in the maternal blood throughout pregnancy. Even if the frequency of fetal cells in the maternal circulation remains to be ascertained, complications of pregnancy such as fetal cells aneuploidies, preeclampsia, abnormal Doppler of the uterine artery without symptoms of preeclampsia, fetal growth restriction and polyhydramnios are associated with an increased feto-maternal trafficking. Based on these observations, previous studies have suggested that determination of the fetal nucleated red blood cell count (FNRBCC) might be a useful non-invasive screening test, either alone or in combination with existing maternal tests, for the non-invasive assessment of aneuploidies, in particular Down syndrome (DS). In this paper we have evaluated the distribution of FNRBCC in a set of 18 normal pregnancies and 18 pregnancies with a trisomy 21-affected fetus, matching for gestational age, maternal age, and, when possible, fetal gender, in order to quantify the difference in the number of fetal cells between the two populations. Maternal blood was collected from each pregnant woman two to three weeks after amniocentesis after knowing the cytogenetic results. Correlation of FNRBCC with the gestational week and clinical status (affected vs. non affected) by multiple regression analysis provided significant results (p < 0.001). Adjusted values of FNRBCC were 48 ± 10.2 in controls and 301 ± 17.01 in DS cases, corresponding to a 6.27fold increase. These retrospective results prompt a prospective evaluation of the use of FNRBCC for screening purposes.

Key words

Fetal nucleated red blood cells - fetal nucleated red blood cells count (FNRBCC) - Down syndrome - general linear model - screening method