Experimental Round Spermatid Injection (ROSI) to Treat Infertile Couples (ROSI)

  • End date
    Dec 9, 2024
  • participants needed
  • sponsor
    Wake Forest University Health Sciences
Updated on 28 February 2022
in vitro fertilization


The purpose of this research study is to evaluate if special types of cells called round spermatids can be gathered from men with non-obstructive azoospermia and used (in absence of elongated spermatids and spermatozoa) to reliably and effectively create pregnancy with a procedure called Round Spermatid Injection (ROSI). This process is similar to In Vitro Fertilization, or 'IVF'. In addition, this study wants to test the safety of ROSI and see what effects (good and bad) it has on embryo created from this method.


Azoospermia is defined as the absence of sperm in the ejaculate. Around 1% of general population suffers from azoospermia. Men who were rendered infertile due to a non-obstructive azoospermia, who have been subjected to Testicular Sperm Extraction (TESE) surgery and found to be lacking elongated spermatids or spermatozoa, are commonly advised to consider utilizing a sperm donor or apply for adoption. It is reported that ~30% of men with non-obstructive azoospermia lack elongated spermatids and spermatozoa but may still produce round spermatids (less mature form of haploid germ cells) in their testicles. Round Spermatid Injection (ROSI) technology to fertilize oocytes is not a brand-new technology, however, it is plagued with notoriously low efficiency. Despite this limitation, it has been reported that most of these patients still desire to have the ROSI procedure instead of applying directly for other options, i.e. sperm donation or adoption.

High failure rate of traditional ROSI has been attributed to a few potential causes:

  1. Incorrect selection of round spermatids (to distinguish from diploid spermatogonia cells)
  2. Using round spermatids that were already in the process of degeneration
  3. Incomplete imprinting in the round spermatid
  4. Incomplete activation of oocytes Recently Tanaka and colleagues in Japan established a new ROSI method and reported over 90 babies born via this method1. They described a new method of round spermatid selection and oocyte activation using NEPA21 super electroporator (10 minutes prior to round spermatid injection).

Babies born from this new ROSI method in Japan have been evaluated for developmental and cognitive differences for 2 years1. Babies conceived with ROSI were found to have a shorter gestation times, and lower body weight at 12 and 18 months when compared to their naturally conceived counterparts, but also showed an increased birth weight and showed no body weight differences at 24 months of age. No diseases resulting from genetic anomalies have been reported thus far, but the relatively small sample sizes present in the literature needs to be tested in larger cohorts. Therefore, this effective ROSI method should still be considered as an "experimental fertility treatment".

Condition Infertility, Male
Treatment Round Spermatid Injection (ROSI), Half ROSI-half Sperm Donor Fertilization
Clinical Study IdentifierNCT04298255
SponsorWake Forest University Health Sciences
Last Modified on28 February 2022


Yes No Not Sure

Inclusion Criteria

Males with no elongated spermatids or spermatozoa present but with round spermatids present on TESE (Testicular Sperm Extraction)
Male diagnosed with non-obstructive Azoospermia
Male partner 18
Female partner greater than 18 years of age and less than 38 years of age or Anti Mullerian Hormone (AMH) greater than 2 ng/ml

Exclusion Criteria

Males with obstructive azoospermia
Males with presence an adequate number of elongated spermatids or spermatozoa
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact



Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note