Semen Analysis
By performing semen analysis on a freshly produced semen sample a rough estimate of the potential of that sample is obtained. The analysis is a very basic fertility test and only concentrates on the physical and morphological aspects of the sperm. In most cases, a normal semen analysis show a good potential in fathering a child, however, one has to bear in mind that there are many other factors playing a role. The optimum period of abstinence (no sexual activity or ejaculation) before producing a semen sample for analysis is 4 days, however, anywhere between 2 and 5 days will suffice.
The London Fertility Centre (LFC) recommends patients to produce their semen samples on site in our dedicated production rooms. In exceptional circumstances patients may produce their sample off site and bring it to the laboratory. This is not recommended as the time between production and analysis is crucial and it may not be possible to reach the laboratory within the recommended 1 hour time frame. Contact a member of the laboratory team before arrangements are made regarding this.
When a semen analysis is performed, certain parameters of the semen sample are measured and compared to the normal values according to the World Health Organisation (WHO) standards. The measured parameters will fluctuate from one sample to the next for the same patient and one need to consider the fact that it takes 3 months for sperm to be produced. Thus, the effect of excessive smoking, drinking or the use of recreational drugs, or illness is only seen in the quality of the sperm 3 months afterwards. The following parameters are measured:
- Volume: The volume of the sample could be between 2-5 ml. The volume is often directly related to the period of abstinence, with shorter abstinence periods often reflecting smaller volumes.
- Viscosity: A slightly viscous sample is normal. When semen is initially produced, it is very viscous. We allow a 15-20 minute period for the samples to liquefy before the analysis is performed. Very watery samples are often an indication that the sample contains very few sperm or none at all.
- Density: This reflects the sperm count and is expressed as [million per ml of semen sample]. 20 million sperm or more per ml of semen is considered to be normal. Counts below this norm do not necessarily imply male factor infertility and could be a result of a very short period of abstinence.
- Motility: The percentage of the sperm in the sample that is actually moving. The normal value is 50% or higher. Longer than recommended abstinence periods could result in a decreased motility.
- Progression: This is the way in which the forward motion of sperm is expressed, as a grade out of 4 (4 being the highest). A value of 0 would indicate immotile sperm and 3 would be good forward progression. Values of 2 and higher are considered normal.
- Abnormal forms: The physical appearance or morphology of the sperm (head, mid piece and tail) is assessed and any deviation from the normal morphology is considered as abnormal. Any normal sample could contain between 80-85% abnormal forms. This may sound high; however, one needs to remember that the figures represent million of sperm. If the sperm count is very low, the abnormal forms may not be counted.
- Cells, Debris, Agglutination: These are some secondary observations of the sample and could give further information relating to a patient’s wellbeing. For example, the occurrence of white blood cells could indicate the presence of an infection or cold.
- Anti-body test: Sperm are produced in the testes where it does not come directly in contact with blood. Anti-sperm antibodies occur when the body becomes sensitized to sperm, causing an immune system response that destroys the sperm. Normally, sperm is protected from the immune system by way of a barrier in the testes. In men who have anti-sperm antibodies, this barrier has been broken, allowing the immune cells (i.e. antibodies) to have access to the sperm. Because sperm have a unique antigen surface, their presence is detected by the immune system and triggers a response. Severe or constant injury to the testes could cause contact between sperm and blood, where after anti-bodies could be present on the surface of the sperm. In a very minor degree (≤5-10% of the sperm in the sample) it will not necessarily have any affect but higher percentages could cause the sperm to stick together and subsequently affect their progression and motility.
- A doctor could sometimes request a 24/48 hour survival test to evaluate how the motility and progression of a sperm sample will change from preparation. The sample is washed to remove most of the immotile and very abnormal sperm and concentrated to yield a sample of good motile sperm. The sample is then analysed 24 hours and 48 hours after the day of preparation to observe the change in sperm quality. If the values for any of these parameters are border-line, a repeat semen analysis may be recommended. As mentioned above, it would be most accurate to repeat the analysis only after approximately 3 months of leading a healthy lifestyle.
Semen Freezing
A semen freeze may be requested by a patient or physician based on a diagnosis and potential permanent male factor infertility or as part of a treatment cycle. Prior to freezing, a blood screen needs to be performed – at least 24 hours before the intended freeze. There are different blood tests to be performed for different scenarios of treatment. The most important blood tests however are Hepatitis B, Hepatitis C and HIV – to be performed for all freezes. Please check with your physician or the embryology laboratory before you set up your appointment to find out if you require additional blood tests (for example known sperm donors or surrogacy).
Consent forms for freezing need to be completed and signed prior to the sample being frozen. These include our in-house consent forms as well as obligatory consent forms from the Human Fertilisation and Embryology Authority (HFEA).
Following production of the semen sample, a semen analysis is performed as described above. Cryo-protectant is added to the semen in a 1:1 dilution. The sperm is frozen in large plastic vials (between 1.0 and 1.8ml per vial). The vials are all labelled with the patient’s surname, patient number and date of freeze and witnessed to be correct by a second person.
The semen samples are frozen in liquid nitrogen vapour over a 1 hour period which allows a gradual slow cooling of the samples. Afterwards the samples are placed and safely stored in storage vessels containing liquid nitrogen at a temperature of -196C. The vessels are self supporting and topped up with fresh liquid nitrogen on a weekly basis when their individual alarms are checked as well.
LFC cannot guarantee the rate of survival of the sperm once it is thawed, but we usually observe a survival rate of approximately 50%. Samples that are initially poor when frozen might have a much lower survival rate or in severe circumstances show no survival at all.
Initial consent to freeze sperm is valid for a maximum of 10 years or any other time period less than 10 years stated by the patient. The initial semen analysis, semen freeze and 1st years’ storage is all payable on the day of producing the sample.
Payment options for semen storage
In the event of cryopreservation of sperm, patients are liable to pay LFC an annual storage charge after the first year’s storage. There are two methods of payment open to patients: firstly, patients are able to pay for annual storage by monthly instalments; and secondly, patients are able to pay annually. You will be asked to complete a payment form in order for LFC to process your preferred method of payment. Most LFC patients have opted to pay by monthly instalment as this enables them to spread the payment throughout the year. It is crucial that patients stay in touch with LFC and update us on any change of address or telephone numbers. If the letters fail to reach the patient and they have not consented to discard the samples, they will still be billed every year.