Sperm collection and preparation
Sperm collection is done by masturbation into a sterile cup, either at the hospital in the room provided for the patient, or at home provided that the travel time between home and hospital is +/- 1 hour and the temperature of the sample is preserved (body temperature). It is recommended to respect 2 to 5 days of sexual abstinence.
The preparation of sperm consists of:
- removing the seminal fluid (a fluid that largely makes up semen; it nourishes and transports the sperm to the vagina).
- selection and concentration of the most mobile sperm.
The technique for preparing sperm used in the laboratory is called density gradient.
An evaluation of the quantity and mobility of sperm (spermogram) is performed before and after any preparation.
When no sperm is detected during the first spermogram, another preparation technique (Percoll gradient) can be performed to concentrate the sample to see if any sperm are present.
Surgical sperm retrieval
If one or more ESP tests are negative, a surgical sperm retrieval is considered. This involves an epididymal puncture and/or a testicular biopsy.
Epididymal puncture
The epididymis is a canal adjacent to the testicle that allows for the maturation and storage of sperm (acquisition of their mobility). It connects the testicle (the place of sperm production) to the vas deferens (the transport zone towards the prostate and ejaculatory ducts). An epididymal puncture consists of aspirating the contents of the epididymis, using a fine needle, of sperm that may be blocked in the canal due to an obstruction (called obstructive azoospermia). The biologist observes the presence or absence of spermatozoa under a microscope.
If spermatozoa are present, they are frozen at -196°C (see sperm freezing). They can be used later for intracytoplasmic sperm injection (ICSI) in in vitro fertilization.
Note that the epididymal aspiration can be converted to a testicular biopsy if it turns out negative.
Testicular biopsy
In case of secretory azoospermia, meaning a problem with sperm production, a testicular biopsy must be performed. Small pieces of testicular tissue are taken under general anesthesia. The biologist examines under the microscope whether or not sperm cells are present.
If sperm is present, they are kept in our incubators for 24 hours to complete their maturation and are then frozen at -196°C (cf sperm freezing). They can be used later in an ICSI during in vitro fertilization.