Applied research of combined G-banding and array-CGH in the prenatal diagnosis of ultrasonographic abnormalities in fetuses

Objective To use combined comparative genome hybridization （array-CGH） and conventional karyotype analysis to study the relationship between ultrasonographic abnormalities of fetuses and chromosomal aberrations. Methods One hundred twenty two fetuses with ultrasonographic abnormalities in middle and late trimesters suspected with chromosomal abnormalities were collected between March 2012 and February 2013. Results The pregnant women had an average age of 31 yr （22-38）, among whom 35 were above the age of 35. The average gestational age was 27＋5 weeks （18-37 weeks）, and the most common abnormal findings have involved heart, central nervous system and bones. Multiple malformations were found in 49 cases. The success rate of the combined methods was 100%. In 24 （19.7%） of the cases, a chromosomal abnormality was detected. Among all cases, 16 （13.1%） were detected by the combined method （12.3%）. Seventeen cases （13.9%） of chromosomal abnormalities and 4 cases （3.3%） of polymorphic variation were detected by karyotype analysis, and 23 cases （8.9%） of abnormalities were detected by array-CGH. Meanwhile, 7 cases （5.7 %） of abnormalities were detected by array-CGH, but the results of karyotype analysis were normal. One case （0.8%） with low level of chromosome chimerism detected by the karyotype analysis was missed by array-CGH. Conclusion The results suggested that multiple congenital deformity of the fetus has a strong correlation with chromosomal abnormalities. For fetuses with ultrasonographic abnormalities, array-CGH can improve the detection sensitivity of the chromosomal disease. Key words: Prenatal ultrasound diagnosis;  G-banding;  Array comparative genomic hybridization