[Detection of fetal chromosomal aneuploidy in pregnant women at advanced maternal age during the first trimester].

Objective: To investigate the value of maternal plasma cell-free fetal DNA (cff-DNA) examination in detection of fetal chromosomal aneuploidy in pregnant women at advanced maternal ages during the first trimester of pregnancy.

Methods: A total of 136 pregnant women (11 to 13+6 gestational weeks) with advanced maternal ages were screened for fetal chromosomal aneuploidy with ultrasound and maternal plasma cff-DNA examination during March 1, 2011 to August 31, 2013, and the results were then confirmed by karyotype analysis and fluorescence in situ hybridization (FISH).

Results: Of the 136 women examined, cff-DNA screening detected chromosomal aneuploidy in 5 cases, including trisome-21 in 3 cases, trisome-18 in 1 case, and 45,X in 1 case as confirmed subsequently by karyotype analysis. Ultrasound screening reported a normal finding in one case of trisomy-21, thickening of the NT in the case of trisomy-18, and fetal anasarca in the case of 45,X. Karyotype analysis and follow-up of the women did not find chromosomal abnormality in the 131 negative cases screened by cff-DNA detection.

Conclusion: Screening of material plasma cff-DNA allows accurate and early detection of fetal chromosomal aneuploidy in women of advanced maternal ages to avoid unnecessary invasive antenatal examinations.