ROSI (ROUND SPERMATID INJECTION)

Cyprus IVF ROSI (Round Spermatid Injection) Method

ROSI (Round Spermatid Injection) is a specialized microinjection technique used in in vitro fertilization (IVF) treatments. This method involves the use of immature sperm cells, called round spermatids, in men who are stuck in the early stages of sperm production and are unable to produce mature sperm (spermatozoa).

In Which Situations Is ROSI Used?

In cases of azoospermia (absence of sperm in the semen), especially in men with arrested spermatogenesis (sperm production).

When mature sperm cannot be found even with methods such as testicular sperm extraction (TESE).

When spermatid production has stopped at the spermatic cord, but stem cells (spermatogonia) or spermatocytes are present.

How Is ROSI Performed?

Testicular Biopsy: Micro-TESE searches for spermatids (round or elongated) in the testicular tissue. Spermatid Selection: Immature spermatids are identified under special microscopes.

Injection: The selected spermatid is injected into a woman's egg (oocyte) using a technique similar to ICSI.

Embryo Development: If fertilization is successful, the embryo is developed in the laboratory and transferred to the uterus.

Rosi Success Rates and Risks

Low Fertilization Rate: Because spermatids do not fully package their DNA, fertilization rates are lower than with conventional ICSI (~30-40%).

Embryo Quality: The risk of aneuploidy (chromosomal abnormalities) in the resulting embryos may be increased.

Pregnancy Chance: Live birth rates range from 10-20%, but this depends on the center's experience and patient factors.

Controversies Regarding Rosi

Ethical and Legal Status: In some countries, Rosi is still considered experimental and limited in routine clinical practice.

Genetic risks: The risk of epigenetic disorders in the fetus due to the immature DNA of spermatids is theoretically discussed.

ROSI Application in Cyprus

The embryologists at the Omni IVF Clinic in Cyprus received training in ROSI from the team that developed the ROSI technique in Japan and have added it to our treatment options.

Alternatives

Searching for mature sperm with Micro-TESE (if available).

Using donor sperm.

Spermatogonial stem cell research (still in the experimental phase).

Conclusion: While ROSI offers hope for men with severely impaired sperm production, its success rate is limited. A detailed urology and reproductive genetics consultation is essential.