Azoospermia is the term that’s used when a standard semen analysis finds no sperm in the ejaculate. However, a revolutionary new procedure, the Extended Sperm Search & Microfreeze (ESSM), finds and freezes small numbers of sperm in 44% of men with azoospermia. This groundbreaking lab test is performed by dividing the entire semen sample into 5 micro-liter droplets and carefully scanning the drops under a high-powered microscope. Any sperm located are placed on a specialized device, called SpermVD, and cryopreserved for use in intracytoplasmic sperm injection (ICSI-IVF).

The SpermVD’s innovative design allows individual sperm to be transferred to a microdroplet for freezing. Because the sperm are successfully frozen in such a small quantity of fluid, over 90% of them survive the freeze and thaw process, and also makes them easily found when thawed on the day they are needed to inject into their partner’s egg (ICSI).  

  • This makes it much more likely that sperm will be found than when the sperm are frozen in conventional vials.
  • This makes finding sperm faster, so that they can be injected as soon as possible after the eggs have been retrieved from his partner, which optimizes fertilization and pregnancy outcome rates.

This procedure was introduced to us by Mordechai Koenig of ATIME who has been tireless in his patient advocacy and in his commitment to bring this procedure to the U.S. and to our attention. As a result, Maze is currently the only laboratory in the U.S. offering this procedure. 


If you’ve been diagnosed with one of the following, you may be a candidate for ESSM:

  • Azoospermia: no sperm observed in the ejaculate in a conventional semen analysis; 44% of azoospermic men will have sperm found and successfully frozen
  • Cryptozoospermia: where only a very few sperm can be found, even after centrifuging and concentrating the specimen; almost all of these men will have a successful ESSM and be able to proceed with IVF/ICSI.
  • Severe Oligozoospermia: sperm concentration less than 1 million/mL

Dr. Michael Werner, Maze Lab Director and a fellowship trained urologist specializing in male infertility, feels strongly that every man with the diagnosis of azoospermia or cryptospermia should undergo an ESSM prior to considering sperm mapping or testicular sperm extraction (micro-TESE). ESSM is non-invasive and may be performed as many times as needed. The surgical extraction procedures are invasive and may cause some damage to the testicles. 

However, if the ESSM does not find sperm, sperm mapping followed by micro-TESE (if areas of sperm production are found on the sperm mapping) is a viable option and should be strongly considered.

ESSM test finds sperm in azoospermic patient, yielding 7 healthy embryos.

“I was told I was azoospermic after going to several well-known fertility centers in the tri-state area. I then came to Maze Laboratories for a standard semen analysis, which also showed zero sperm count. However, after having Maze’s ESSM lab test, 42 sperm were recovered and safely stored. In collaboration with the IVF lab, my wife and I are happy to say that 7 healthy embryos were developed!”

– J, 37 –

Notable Publications

  1. Dr. Michael Werner shares background & results for Extended Sperm Search & Microfreeze, with A Time. (March 2021) Read Article
  2. Fertility Outcomes – Extended Sperm Search
  3. Microfreeze- A Novel solution for freezing small numbers of spermatozoa


If you believe you're an appropriate candidate for the ESSM procedure, we encourage you to contact us as soon as possible. A phone consultation will be conducted to discuss the procedure in detail, answer any questions you may have and schedule the appointment. You will then be required to send your records to Dr. Werner for review.

* The Extended Search procedure, which was developed and is performed in Israel by MFC Labs, is exclusively performed in the U.S. by Maze Health. Special thanks to Mordechai Koenig, and ATIME for notifying us about this groundbreaking technique.

Last Updated: April 2022