Complex chromosome abnormality in patients with in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI)

Abstract

To evaluate the incidence of complex chromosome abnormality in embryos derived from IVF and ICSI and its relationship to embryo stages and grading. A retrospective data analyses. Patients who underwent IVF or ICSI and also had PGD were included in the study. PGD was performed by FISH with probes for chromosomes 13, 18, 21, X and Y 3 days after egg retrieval. Additional chromosomes 8, 9, 14, 15, 16, 17, 20 and 22 were examined if indicated. Each embryo was scored by cell number and grade (A-D) on the day of PGD. 1. PGD was performed on 1119 embryos derived from IVF and 460 embryos derived from ICSI. Chromosomal abnormalities were 51.7% and 51.1% in embryos of IVF and ICSI groups, respectively. There were no differences in rates of polyploidy (7.0 vs. 5.9%), haploidy (1.7 vs. 1.3%), aneuploidy (25.0 vs. 17.4%), and complex chromosome abnormality (18.8 vs. 26.5%) between IVF and ICSI groups. 2. The rate of aneuploidy was not different among embryos with different numbers of blastomere (20–30%). However, the rate of complex chromosome abnormality was significantly lower in embryos at 8 cell stage (9 vs. 5%) and higher in embryos with lower cell number (34 vs. 36%) for IVF and ICSI cycles (Fig 1). 3. Complex chromosome abnormality was also rare in embryos with good grade (8 vs. 4% for grade A) and common in embryos with poor grade (53 vs. 48%for grade D) for IVF and ICSI cycles (Fig 2). 1. The PGD results from both IVF and ICSI derived embryos revealed a correlation between the incidence of complex chromosome abnormality and cell number of embryos. 2. Slow growing embryos are associated with more complex chromosome abnormality. 3. Embryo grade is the most important predictor for complex chromosome abnormality. 4. ICSI, performed for male infertility, doesn't change chromosomal pattern revealed by PGD.