Intracytoplasmic morphologically selected sperm injection (IMSI): is it a good choice after two or more IVF or ICSI failures?

Abstract

OBJECTIVE: To study outcome of IMSI after previous failures of conventional IVF or ICSI techniques.DESIGN: A crossover study with each subject acting as their own control.MATERIALS AND METHODS: After at least two previous failures of IVF or ICSI, seventy five infertile couples were offered the IMSI technique, regardless of the initial sperm evaluation. In order to control all of the potential confounders (age, ovarian reserve, aetiology and duration of the infertility), each IMSI cycle was compared to the previous IVF or ICSI cycle of the same patient. Main outcome measures were: fertilization rate, embryo quality, percentage of good quality blastocysts obtained after extended culture. Clinical pregnancy and birth rates were also evaluated. Paired t-test and Mc Nemar test were used for continuous and binary variables, respectively.RESULTS: The mean time interval between IMSI and the previous control cycle was 9.0 ± 5.5 months. No differences were observed between IMSI and controls concerning cycle characteristics such as stimulation protocol, mean number of FSH doses used, mean duration of ovarian stimulation, peak estradiol level and endometrial thickness at ovulation induction, and total number of oocytes retrieved and inseminated. Fertilization rates were significantly increased in IMSI compared to control cycles (72.2% versus 63.3%; p=0.02). The percentage of top embryos obtained at day 2 was also increased in IMSI compared to control cycles (89.0% versus 81.7%; p=0.03). Extended embryo culture up to blastocyst stage was possible in 41.3% of IMSI cycles versus 26.7% of IVF or ICSI cycles (p=0.04). In these cases, the mean number of blastocysts obtained was higher in IMSI cycles (1.5 ± 1.9) than in IVF or ICSI cycles (1.0 ± 1.2) (p=0.03). Blastocyst transfer was possible in 18.7% of IMSI cycles versus 4.0% of control cycles (p=0.007). While no ongoing pregnancy was encountered in control cycles, IMSI treatment resulted in clinical pregnancy and birth rates of 29.3% and 18.6%, respectively. All born babies are normal and healthy.CONCLUSIONS: After at least two IVF or ICSI failures, IMSI technique seems to offer a better fertilization rate with a better embryo quality at day 2, which is associated with more blastocyst development and transfer. Good pregnancy rates and outcomes with IMSI may be explained by these observations and support the use of this technique after repeated failures of IVF or ICSI. OBJECTIVE: To study outcome of IMSI after previous failures of conventional IVF or ICSI techniques. DESIGN: A crossover study with each subject acting as their own control. MATERIALS AND METHODS: After at least two previous failures of IVF or ICSI, seventy five infertile couples were offered the IMSI technique, regardless of the initial sperm evaluation. In order to control all of the potential confounders (age, ovarian reserve, aetiology and duration of the infertility), each IMSI cycle was compared to the previous IVF or ICSI cycle of the same patient. Main outcome measures were: fertilization rate, embryo quality, percentage of good quality blastocysts obtained after extended culture. Clinical pregnancy and birth rates were also evaluated. Paired t-test and Mc Nemar test were used for continuous and binary variables, respectively. RESULTS: The mean time interval between IMSI and the previous control cycle was 9.0 ± 5.5 months. No differences were observed between IMSI and controls concerning cycle characteristics such as stimulation protocol, mean number of FSH doses used, mean duration of ovarian stimulation, peak estradiol level and endometrial thickness at ovulation induction, and total number of oocytes retrieved and inseminated. Fertilization rates were significantly increased in IMSI compared to control cycles (72.2% versus 63.3%; p=0.02). The percentage of top embryos obtained at day 2 was also increased in IMSI compared to control cycles (89.0% versus 81.7%; p=0.03). Extended embryo culture up to blastocyst stage was possible in 41.3% of IMSI cycles versus 26.7% of IVF or ICSI cycles (p=0.04). In these cases, the mean number of blastocysts obtained was higher in IMSI cycles (1.5 ± 1.9) than in IVF or ICSI cycles (1.0 ± 1.2) (p=0.03). Blastocyst transfer was possible in 18.7% of IMSI cycles versus 4.0% of control cycles (p=0.007). While no ongoing pregnancy was encountered in control cycles, IMSI treatment resulted in clinical pregnancy and birth rates of 29.3% and 18.6%, respectively. All born babies are normal and healthy. CONCLUSIONS: After at least two IVF or ICSI failures, IMSI technique seems to offer a better fertilization rate with a better embryo quality at day 2, which is associated with more blastocyst development and transfer. Good pregnancy rates and outcomes with IMSI may be explained by these observations and support the use of this technique after repeated failures of IVF or ICSI.