ANEUPLOID SPERM

• Chromosomal aberrations are common among genetic abnormalities, causing genetic syndromes, for which there is no definitive treatment. Most of these abnormalities are new mutations that arise during the gametogenesis of the parents, and these are also the cause of reproductive abnormalities such as miscarriage, stillbirth or preimplantation failure.
• Theoretically, sperm aneuploidy will cause embryo aneuploidy. But in practice using ICSI, is it possible to select aneuploid sperm?

Case 47, XXY – Abnormal sex chromosomes originating from father

• Sperm aneuploidy can occur in any sperm sample, with rates ranging from 0 to 0.15% per haploid chromosome. However, in infertile men, sperm aneuploidy occurs with greater frequency than normal.
• Sperm aneuploidy helps to assess the rate of aneuploidies in semen samples of men. The ratio of aneuploidy of 1 chromosome = number of abnormal sperm / total number of sperm analyzed.
• Sperm aneuploidy will determine the percentage of aneuploid sperm in the sperm sample on chromosomes 13, 18, 21, X and Y.

Effects on ART

• An aneuploid sperm when fertilized creates an aneuploid embryo. Diploid sperm to form triploid embryo
• Reduce the rate of successful pregnancy after ICSI when the aneuploidy rate is high
• Increased chance of miscarriage when aneuploidy rate is high
• Increased aneuploidy associated with detected aneuploidy (Down, Klinefelter or Turner syndrome)

Affects the embryo

• An aneuploid sperm when fertilized will lead to an aneuploid embryo.
• If not screened, the percentage of babies born with birth defects will be higher.

 Effects on pregnancy

• Aberrations of spermatozoa have a strong association with recurrent miscarriage, which is one of the factors that cause unexplained consecutive miscarriage and consecutive implantation failure.

The rate of sperm aneuploidy was higher in the group of consecutive miscarriages than in the control group (SMD: 1.07, 95% CI: 0.39-1.75, P<0.01)

Sperm aneuploidy and recurrent pregnancy loss:

A systematic review and meta-analysis

- Pu et al., Cogent Biology (2020), 6: 1759393

• Find out the cause of reproductive abnormalities: infertility, infertility, multiple miscarriages, pre-implantation failure
• Predicting the inheritance of chromosomal abnormalities from fathers to offspring;
• Help doctors make treatment options in assisted reproduction: performing PGT-A, using donor sperm…

• Miscarriage, recurrent stillbirth.
• Repeated failure to implement assisted reproductive measures.
• Men with genetic abnormalities: HC Klinefelter, HC cyclic, cases of inversions, translocations, microdeletions on the Y chromosome.
• Men with abnormalities in sperm count, function and morphology: oligospermia, HC OAT, azoospermia due to obstruction or not.
• Men who perform treatments that can affect spermatogenesis such as chemotherapy, radiation therapy, etc.

Using Fluorescence In Situ Hybridization (FISH) technology

• Men were instructed to take samples according to WHO guidelines (2021): abstain from ejaculation for 2-7 days; clean genitals and hands, collect by masturbation, collect the entire sample into the prepared semen container
• For the first 1 hour, store semen at room temperature. After 1 hour, store semen at 4 – 80C, avoid freezing. Test samples within 24 hours of ejaculation.
• Sperm samples after washing are stored at 4 – 80C, transferred to the Lab within 48 hours after ejaculation.

Sperm sampling - Sperm washing - Sperm spreading and immobilization - Extraction of sperm chromosomes - Hybridization - Detection - Analysis.

Sample: Washed and filtered sperm

Storage: Washed and filtered sperm Store at 4-8 degrees Celsius (not more than 48 hours)

Time to return results: 10 days after receiving the sample.

 The method to evaluate Sperm aneuploidy is performed based on FISH method (Fluorescent In Situ Hybridization) - an intermediate technique between cellular genetics and molecular genetics. FISH was performed using the hybrid DNA fragment of chromosomes 13, 18, 21 and X, Y.