Diagnosing and preventing inherited disease: Pregnancies following pre-conception diagnosis of common aneuploidies by fluorescent in-situ hybridization

Chromosomal aneuploidies contribute considerably to the low pregnancy rate in in-vitro fertilization (IVF). The objective of this experimental work was to explore the possibility of detecting common aneuploidies in oocytes by polar body sampling. The study included 45 infertile patients of advanced maternal age participating in an IVF programme. The first polar body was removed prior to fertilization or both the first and second polar bodies were removed after fertilization and studied by fluorescent in-situ hybridization (FISH) using chromosome-specific probes for chromosomes X, 18 and/or 13/21. Of 155 oocytes with FISH results, 36 demonstrated chromosomal abnormalities. Of 119 oocytes predicted to be free from aneuploidy of chromosomes X, 18 and/or 13/21, 72 were normally fertilized, cleaved and transferred in 23 treatment cycles, which resulted in two healthy deliveries and three ongoing pregnancies confirmed to be unaffected by chorionic villous sampling. The method may appear useful for the detection of oocytes with common chromosomal aneuploidies in IVF patients of advanced maternal age.