O-198 The decline in semen quality parameters enhances mosaicism in trophectoderm biopsy of human blastocysts
Authors: Sengebaljir D , Baatarsuren M , Ganbaatar C , Baljinnyam L , Erdenekhuyag B , Enkhbaatar S , Boris T , Ganbat G , Dorjpurev A , Amarsaikhan A , Tumur-Ochir G , Khangarid A , Jamiyansuren J 
Published: July 2024

Abstract

Study question
Do poor sperm parameters impact chromosomal analysis compared to sperm with normal parameters?

Summary answer
Fertilization with more than two abnormal patterns, including severe oligoasthenoteratozoospermia sperm, may increase the rate of embryo mosaicism.

What is known already
Sperm cells constitute the genetic half of the embryo, and the male factor plays a crucial role in embryo chromosome integrity. While PGT-A is widely used to enhance IVF outcomes, the influence of male factors on embryo genetics remains underexplored. We aimed to determine the effect of semen profile on the outcome of PGT-A cycles performed at the blastocyst stage.

Study design, size, duration
A single-center retrospective study conducted between January 2019 and July 2023 analyzed 609 blastocysts with Next Generation Sequencing (NGS) of trophectoderm (TE) biopsies. Four study groups were formed based on sperm parameters: normozoospermia (N), moderate male factor (MMF), severe oligoasthenoteratozoospermia (s-OAT), obstructive azoospermia (OA).

Participants/materials, setting, methods
Patients treated with a minimal ovarian stimulation protocol. PGT-A cycles were divided into three paternal age groups. OUTCOMES: Euploidy, aneuploidy, mosaicism rates; blast formation time; good-quality blastocyst rates. METHODS: Multivariate logistic analysis, Chi-squared tests, and STATA 12.1 statistical software.

Main results and the role of chance
In the 609 TE biopsied blastocysts, euploidy rate was 49.9%, aneuploidy rate was 31.5%, and mosaicism rate was 18.6%. Paternal age ≥43 increased aneuploidy risk compared with &lt;35 (40.1% vs 26.1%, p &lt; 0.05). The euploidy rate and aneuploidy rate were no different in MMF, s-OAT, and OA compared with N (44.8%, 40.6%, and 42.1% vs. 54.2%; 36.8%, 25.0%, and 31.6% vs. 30.5%). Mosaicism rates were significantly difference between sperm parameter groups (N 17.1%, MMF 18.4%, s-OAT 34.4% and OA 26.3%, p &lt; 0.05). In logistic regression analysis adjusted for confounders, severe oligoasthenoteratozoospermia showed 2.5 times higher mosaicism rate (aOR 2.58; 95% CI 1.08-5.08, p = 0.027). The good-quality blastocyst rate was significantly reduced in the OA compared with N, MMF, and s-OAT (21.1% vs 43.4%, 39.2% and 37.5%, p &lt; 0.05). No impact of semen parameters on blastocyst formation time and vitrification time outcomes was observed.

Limitations, reasons for caution
Retrospective, single-center study. Excludes DNA fragmentation index and TESE results, impacting sperm quality evaluation.

Wider implications of the findings
Severe oligoasthenoteratozoospermia is positively associated with mosaicism rate. Poor sperm parameters lead to mosaic embryos. Couples undergoing PGT-A for male factors should discuss potential outcomes. Patients with abnormal semen parameters should consider pretreatment for improved semen quality. Results useful for genetic counseling and clinical decision-making.

Trial registration number
None