Prenatal karyotyping using fetal blood obtained by cordocentesis: rapid and accurate results within 24 hours.
Spontaneously-dividing nucleated erythrocytes present in prenatal cordocentesis samples can be used to obtain fetal karyotype information within 24 hours. Following a modified protocol we performed rapid chromosome analysis on fetal blood from 70 second- and third-trimester fetuses. In all cases cordocentesis was performed following detection of ultrasound abnormalities. Cytogenetic diagnoses were obtained within 24 hours from 59 (84.3%) of the 70 samples. Follow-up chromosome analysis from mitogen-stimulated cultures showed concordant results in 57 of the 59 successful cases. In one case a mosaicism for 45, X[4]/46,X,i(X)(q10)[4] was detected in unstimulated harvest while mitogen-stimulated preparations showed only the 46,X,i(X)(q10) line. In the second case, a marker chromosome was identified in all 5 cells analyzed from the unstimulated harvest while mitogen-stimulated cultures showed only 4 out of 100 cells with the marker.
Tharapel
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Cytogenetics Reference Laboratory, Pathology and Laboratory Medicine Services, Veterans Affairs Medical Center, Memphis, TN 38104, USA. atharapel@utmeml.utmem.edu
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Shulman
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Tharapel
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D017218:Cordocentesis; D005260:Female; D005312:Fetal Blood; D006801:Humans; D007621:Karyotyping / Q000379:methods*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D011296:Prenatal Diagnosis / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results; D013997:Time Factors