Does ICSI increase the incidence of chromosomal aberration in embryos?

Abstract

A chromosomal aberration of fetus is a major risk factor of first-trimester miscarriage in both spontaneous pregnancy and pregnancy after reproductive treatment. It increases with age. In this study, we assessed effects of insemination methods and donor ages on the incidences of chromosomal aberrations. Retrospective study. Two hundred fifty five patients who underwent IVF and ET between January 2006 and December 2009, and suffered first-trimester miscarriage were included in this study. All informed consent was obtained from each patient. This study was approved by a local ethical committee. The incidence of chromosomal aberrations in 50 conventional IVF cycles (age: 36.2 years old) and 165 ICSI cycles (36.8 years old) were analyzed according to age. The incidence of chromosomal aberrations of first-trimester miscarriage was 78.6% (169/215). The incidence of chromosomal aberrations in ICSI cycles (81.2%) was significantly higher (P<0.05) than that in cIVF cycles (68.0%). In the group of patients under 34 years old, the incidence of chromosomal aberrations in ICSI cycles (79.5%) was significantly higher (P<0.01) than that in cIVF cycles (38.9%). However, there were no differences between insemination methods in the groups of 35 and 39 years old (cIVF: 73.7% vs. ICSI: 75.7%), and of 40 and older (cIVF: 100% vs. ICSI: 91.7%). Data of the present study revealed that the incidence of chromosomal aberrations in the cases of first-trimester miscarriage in ICSI cycles was high compared with that in cIVF cycles in the group under 34 years old. It was assumed that an increase of chromosomal aberrations in ICSI cycles was caused by more cases of male factor infertility. On the other hand, the aberration rate was over 70% in both insemination methods over 35 years old. It was thought that this was because an age factor strongly related in addition to a male factor.