Yl. Zheng et al., DEMONSTRATION OF SPONTANEOUSLY DIVIDING MALE FETAL CELLS IN MATERNAL BLOOD BY NEGATIVE MAGNETIC CELL SORTING AND FISH, Prenatal diagnosis, 15(6), 1995, pp. 573-578
We investigated a case of massive fete-maternal bleeding by using nega
tive magnetic cell sorting (MACS) and fluorescent in situ hybridizatio
n (FISH). A 37-year-old pregnant woman had an uncomplicated amniocente
sis for advanced maternal age at 16 weeks' gestation. The fetal karyot
ype was 46,XY. At 19 weeks' gestation, she had a minor car accident an
d slight vaginal bleeding. A subsequent Kleihauer-Betke test showed a
140 ml fete-maternal haemorrhage. Serial sonographic examinations indi
cated a normal fetus and placenta. We performed FISH analysis on mater
nal peripheral blood at 25 weeks. Anti-CD45 and MACS were used to depl
ete maternal leucocytes, enriching the proportion of fetal nucleated e
rythrocytes present. The isolated cells were analysed by using dual-co
lour FISH with X and Y specific probes. Approximately 65 800 nucleated
cells were obtained after MACS depletion. A total of 234 cells were a
nalysed by FISH. The results revealed that 70 of the nucleated cells (
30 per cent) were male with one X and one Y signal. Among these cells,
six male metaphases were observed in spontaneously dividing cells.