Semen specimen


The day prior to oocyte harvesting, the gynaecologist will inform the couple about how to collect the semen specimen and about how, when and where to deliver the specimen.

The semen specimen to be used for the insemination of the oocytes is collected on the same day as the follicular puncture. Only in exceptional cases would more than one semen specimen be requested, with the aim of selecting the best quality sperm. In exceptional circumstances, when difficulties are envisaged regarding collecting the semen specimen on the day of insemination, the gynaecologist should be informed in order to assess the possibility of freezing a semen specimen before the IVF cycle.

The freezing and thawing process may affect the viability of some sperm, which is why cryopreservation of semen specimens is not recommended in cases of severe oligoasthenozoospermia. Freezing should be conducted at least 3 to 5 days before oocyte retrieval, having previously taken prophylaxis antibiotics to avoid possible contamination of the specimen.

The instructions on how to collect the specimen are as follows:

  • Sexual abstinence for 3-5 days before collecting the sample.
  • Antibiotic prophylaxis to avoid possible contamination of the specimen.
  • The semen should be collected by masturbation, taking the appropriate hygiene measures.
  • The semen specimen should be collected in a wide-mouth sterile container which will be provided beforehand or which may be bought at a chemist (like those used for urine collection) and it should be labelled with name, days of abstinence and time of collecting.
    It is important that the entire ejaculate is collected without losing any.
  • The specimen may be collected on the same day at the centre as there are specific rooms available for this purpose. If the specimen is not collected at the centre, it is important to deliver it to the Andrology Laboratory within a maximum of one hour.
  • On delivering the specimen, information should be provided on whether any medications have been taken or if suffering from fever.

Once in the laboratory, the specimen is processed in order to select the most mobile sperm. Sperm contained in a semen specimen are incapable of fertilising an oocyte. They must undergo a series of physiological changes, known as CAPACITATION, in order to gain this fertilising capacity.
In vivo, sperm capacitation takes place in the female reproductive tract. In vitro, the process occurs in the laboratory using sperm washing and density gradient techniques.

There are two main objectives of semen processing in the laboratory before insemination of the oocytes:

  • Sperm washing: to eliminate seminal plasma, immobile sperm, sperm with poor mobility and other non-sperm cells.
  • Density gradient: to select sperm with greatest mobility.

It is important to emphasise that the concentration and mobility of the sperm obtained at the end of the process depends on the initial quality of the specimen.

Sperm bank

Donor sperm samples at the Reproductive Medicine Unit at Women's Health Dexeus are obtained from an external certified Bank with whom a collaboration agreement has been established (Androgen SL; Sabater Tobella Análisis SA).

Potential sperm donor candidates must undergo a rigorous examination in order to avoid possible transmission of diseases to offspring. This examination includes sperm analysis (seminogram), genetic screening (karyotype) and an infectious disease screening (hepatitis, syphilis, AIDS, etc).

Sperm donors are selected according to the immunological and phenotypic makeup of the recipient woman (blood group and Rh, weight, height, eye colour, hair, etc).

Data on the donor and female recipient are maintained at the centre under strict anonymity.

Sperm microaspiration/Testicular biopsy

In cases of azoospermia (obstructive or secretory) where no sperm are found in the ejaculate but where the testicles maintain sperm production, sperm may be retrieved following a simple surgical procedure.

On the same day as the follicular puncture, the andrologist will perform a Testicular Sperm Aspiration (TESA) or, if necessary, a Testicular Sperm Extraction (TESE) in the operating theatre under local anaesthesia. The fluid and tissue obtained is deposited in a test tube with the appropriate washing agent and sent immediately to the IVF laboratory, where the embryologist will retrieve the sperm contained in the sample.

There is a possibility that the sample obtained via sperm aspiration or testicular biopsy does not contain sperm suitable for fertilisation.


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