Impact of female age and ovarian reserve on the outcomes of ICSI cycles with either fresh or frozen-thawed testicular spermatozoa retrieved from non-obstructive azoospermic patients

Abstract

To evaluate the influence of female age and ovarian reserve on the outcomes of ICSI cycles with either fresh or frozen-thawed testicular spermatozoa retrieved from non-obstructive azoospermic patients when compared to a large cohort who had undergone ICSI with either fresh or frozen-thawed ejaculated or aspirated sperm. This retrospective cohort study was conducted in a private IVF clinic between August 2011 and December 2015. A total of 550 non-obtructive azoospermic males underwent microdissection testicular sperm extraction (MicroTESE). Over a four-year period, some of the same couples applied for IVF and ICSI was performed using either testicular spermatozoa or frozen-thawed testicular spermatozoa, according to the clinical evaluation of the patients. In the same period 10086 couples applied for IVF and ICSI was performed with either fresh or frozen-thawed ejaculated or aspirated sperm. In the stated time-period, 248 and 150 embryo transfers were derived from fresh microTESE and frozen-thawed microTESE samples, respectively. A total of 8299 embryo transfers derived from either fresh or frozen-thawed ejaculated or aspirated sperm. Embryos were transferred either on day 3, 4 or 5 according to embryo development and the number of embryos to be transferred (one or two). Fourteen and sixteen days after pick-up, serum β-hCG was measured. At 7 weeks, a transvaginal ultrasound was performed to monitor early pregnancy. Clinical pregnancy was defined as fetal heart beat seen by transvaginal ultrasonography. No statistically significant differences were found between the microTESE and ejaculated/ aspirated sperm groups regarding the number of retrieved cumulus-oocyte complexes (COCs) for the five distinct categories (1-5; 6-10; 11-15; 16-20; >20). Clinical pregnancy rates (CPR) varied from 36.9 to 58.1% in the microTESE group for the first and last group, whereas CPR were of 34.35 and 47.7, in the same categories (p=0.59 and p=0.26, respectively). On the other hand, female age was causing a decrease of 4.5 to 6.5% in the CPR of the microTESE group when compared to the ejaculated/ aspirated sperm group for all age categories analyzed (<30; 30-34; 35-37; 38-40; 41-42 and 43≥). The trend in the age-dependent decline was significant (p=0.0158 and p<0.0001, respectively). The CPR was calculated as 56.1 and 50.8% in the ejaculated/ aspirated sperm group and microTESE group for <30 years of age, respectively. No significant differences were found between the ejaculated/ aspirated sperm group and microTESE group regarding CPR in all COC or female age categories. The female age-related decline was significant in both groups and was causing a 4.5 to 6.5% decline in the CPR of the microTESE group. Therefore, microTESE should not be regarded as a factor which aggravates IVF success rates once an embryo transfer could be planned.