P–270 Paternal age and reproductive potential with fresh and vitrified spermatozoa: An analysis of 11016 ICSI donor oocytes
Authors: Parrella A , Ramos B , Vilella I , Garcia-Sifre A , Rogel S , Orteg. Lopez L , Aizpurua J 
Published: August 2021

Abstract

Study question
Does paternal age impair embryo aneuploidy and clinical outcomes in ICSI donor-oocytes cycles when fresh (FRs) and vitrified (VTs) spermatozoa are used?

Summary answer
Paternal age affects clinical outcomes, not embryo aneuploidy. With VTs, young and old men had similar outcomes. With FRs, young men had higher reproductive potential.

What is known already
Advanced paternal age is associated with low quality of sperm and an increase of reactive oxidative species, responsible of the DNA fragmentation, as well epigenetic disorders. In these men, the DNA repair mechanisms have a reduced ability to repair damaged DNA enhancing the likelihood of replication errors in the germ line. This genomic instability of the male gamete entails to chromosome abnormalities, generating potentially a negative effect on implantation and clinical outcomes. In addition, when the maternal oocyte repair mechanisms are not able to compensate quantitatively and qualitatively the sperm damages unrepaired embryos might develop.

Study design, size, duration
This retrospective study includes 848 couples undergoing 905 ICSI donor-cycles between January 2019 and February 2020, with similar quality and number of mature oocytes retrieved. Maternal age of recipients was 40.9±6 years and only those with previously failed cycles with their own oocytes were included. The clinical outcomes and aneuploidy were analyzed in two groups with the male partner being younger (M ≤ 40) or older than 40 years (M &gt; 40).

Participants/materials, setting, methods
This study includes couples that underwent ICSI cycles with donor-oocytes using FRs and VTs ejaculates. Samples were analyzed according to WHO 2010 criteria. An in house-protocol (Vitri-Sperm®) was used to perform spermatozoa vitrification/warming. Embryo quality was assessed with time-lapse technology (Geri®), Aneuploidy Testing (PGT-A) was carried out on blastocyst’s trophectoderm using NGS (Illumina®) and Fisher’s Exact test was used for statistical analysis. P-value was considered statistically significant at a threshold of &lt; 0.05.

Main results and the role of chance
Fresh ejaculate was used in 192 cycles with M ≤ 40 (concentration: 39.4±35 x 106/mL; motility: 35.1±16%) and 242 with M &gt; 40 (concentration: 36±34 x 106/mL; motility: 30±16%) yielding similar fertilization: 75.3% (1785/2369) Vs 75.6% (2232/2938). Comparing M ≤ 40 with M &gt; 40 implantation decreased significantly from 66.6% (92/138) to 54.4% (79/145, P = 0.03), Clinical Pregnancy Rate (CPR) from 68% (85/125) to 54.3% (75/138 P = 0.03). Pregnancy loss from 15.2% (19/125) to 17.3% (24/138), not statistically significant.
Vitrified spermatozoa in 195 cycles with M ≤ 40 (concentration: 4.9±7 x 106/mL; motility: 13.4±9%), and 276 with M &gt; 40 (concentration: 4.3±4 x 106/mL; motility: 13.9±12%) yielded significant difference in fertilization, 76.2% (1841/2416) Vs 72.4% (2386/3293, P &lt; 0.001), respectively. In M ≤ 40 and M &gt; 40 implantation was 51.9% (40/77) Vs 49.1% (60/122) (p &lt; 0.05), CPR was 53% (38/71) Vs 54% (59/109). Pregnancy loss was 16.9% (12/71) Vs 13.7% (15/109), not statistically significance.
In M ≤ 40 undergoing ICSI+PGT-A cycles (N = 43) with FRs, euploidy was 71% (157/221) Vs 73.5% (256/348) in M &gt; 40 cycles (N = 71). Implantation and CPR were equal in FRs groups, 77.1% (27/35) Vs 75.8% (44/58). Using VTs euploidy in M ≤ 40 cycles (N = 63) was 71.9% (210/292), compared to 70.0% (279/399) in M &gt; 40 cycles (N = 82). Implantation and CPR were higher in both groups, 76.5% (36/47) Vs 73.6% (53/72), not statistically significant.

Limitations, reasons for caution
Normo- and oligo-zoospermic patients, with quite different parameters and ethnicities have been included, allowing an analysis on a larger study population, but suitable of being analyzed further by subgroups. Implantation parameters like receptivity or immunologic disorders weren’t addressed. No data have been included on perinatal and obstetrical outcomes for pregnancies.
Wider implications of the findings: Paternal age affects the clinical outcomes and embryo viability, it does not affect embryo aneuploidy when FRs and VTs are used. In ICSI donor-oocytes cycles with VTs, no significant difference in clinical outcome was found between young and older men. However, young men with fresh ejaculate have higher reproductive.

Trial registration number
N/A