What health tests a known sperm donor should complete before donation

When you use a licensed fertility clinic for donor insemination, the clinic screens the donor for you. The donor is tested for a defined panel of infectious diseases, genetic conditions, and semen quality before any arrangement proceeds. The clinic is legally required to do this under the Human Fertilisation and Embryology Authority (HFEA) code of practice, and the results are documented and reviewed by a qualified clinician.

When you arrange a known donor privately, without a clinic, none of this happens automatically. The parties are responsible for arranging and paying for their own screening. This is not a formality. It is the single most important thing you can do to protect the health of the child and the legal position of everyone involved.

This article sets out the specific tests a known donor should complete before any donation arrangement proceeds. It is written for recipients and donors who are arranging a private donation, and for the professionals who advise them.

Infectious disease screening

The donor should complete a full sexually transmitted infection (STI) panel. This is the same panel that the HFEA requires of clinic donors, adapted for private arrangements.

The specific tests are:

• HIV 1 and 2 (antibody and antigen test). HIV can be transmitted through sperm. The window period for the combined antibody/antigen test is approximately 45 days, meaning a donor should be tested at least 45 days after any potential exposure.
• Hepatitis B (surface antigen and core antibody). Hepatitis B is highly transmissible through sperm. A donor who has been vaccinated will test positive for surface antibody, which is not a concern. The test to watch is surface antigen: if positive, the donor is infectious and should not donate.
• Hepatitis C (antibody test). Hepatitis C is less easily transmitted through sperm than hepatitis B, but the risk is not zero. The window period is approximately 8 to 11 weeks.
• Syphilis (Treponema pallidum antibody test). Syphilis is transmissible through sperm and can cause congenital syphilis if the recipient is infected at the time of conception.
• Chlamydia and gonorrhoea (NAAT test, urine sample). These are common bacterial STIs that can cause pelvic inflammatory disease in the recipient and can affect fertility. They are easily treated with antibiotics, but the donor should be treated and retested before donation proceeds.
• Human T-lymphotropic virus (HTLV). This is a retrovirus that can be transmitted through sperm and is associated with adult T-cell leukaemia and neurological conditions. It is included in the HFEA screening panel and should be included in private screening.

All tests should be done through a GP, a sexual health clinic, or a private blood testing service. Home testing kits are available but should not be the sole basis for screening decisions: the sample collection and handling process is less controlled, and the results are harder to document for legal purposes.

The results should be shared in writing with the recipient. A donor who declines to share their results, or who agrees to be tested but does not follow through, is a donor you should walk away from.

Genetic carrier screening

Genetic carrier screening tests whether the donor carries a gene variant that could cause a genetic condition in a child. Everyone carries some recessive gene variants. Most carriers are unaffected because they have one healthy copy of the gene that compensates. The risk arises when both the donor and the recipient carry a variant in the same gene: the child has a 25% chance of inheriting both copies and being affected.

The HFEA requires clinic donors to be screened for:

• Cystic fibrosis (CFTR gene). 1 in 25 people of Northern European ancestry are carriers.
• Sickle cell disease (HBB gene). More common in people of African, Caribbean, and Mediterranean ancestry.
• Thalassaemia (alpha and beta). More common in people of Mediterranean, South Asian, and Middle Eastern ancestry.
• Tay-Sachs disease (HEXA gene). More common in people of Ashkenazi Jewish and French-Canadian ancestry.

For private arrangements, the screening should go beyond these four conditions. Extended carrier panels (sometimes called "extended carrier screening" or ECS) test for 100 to 500 recessive conditions in a single blood or saliva sample. The cost in the UK is approximately £250 to £400 privately, and the results are available in 2 to 4 weeks.

The recipient should also undergo carrier screening. If the recipient carries a variant in a gene that the donor also carries, the risk to the child is 25% per pregnancy. If only one party carries a variant, the child will not be affected (though they may be a carrier). The point of screening both parties is to identify matches where both carry the same condition.

Semen analysis

A semen analysis evaluates the quality of the donor's sperm. The key parameters are:

• Count (million per millilitre). Normal is 15 million or above, per WHO 2021 criteria.
• Motility (percentage of sperm that move). Normal is 40% or above total motility.
• Morphology (percentage of sperm with normal shape). Normal is 4% or above using strict criteria.

A donor with low count, poor motility, or poor morphology may not be a suitable donor for natural insemination, where the sperm needs to travel through the reproductive tract to reach the egg. For clinic-based IUI or IVF, lower-quality sperm can sometimes be used because the sperm is placed directly at or near the egg, but for natural insemination, the sperm needs to be of sufficient quality to complete the journey unaided.

A semen analysis costs approximately £80 to £150 privately in the UK and results are available in 1 to 2 weeks.

Blood type and Rh factor

The donor's blood type and Rh factor should be documented. If the recipient is Rh-negative and the donor is Rh-positive, the child may be Rh-positive, which can cause Rh incompatibility in the pregnancy. This is a manageable condition (the recipient receives anti-D injections during pregnancy), but it needs to be flagged with the recipient's GP or midwife early in the pregnancy.

Why this screening matters more in private arrangements

In a clinic arrangement, the HFEA code of practice requires screening, and the clinic is accountable if it is not done properly. In a private arrangement, there is no regulatory body overseeing the process. If the screening is incomplete or incorrect, and a child is born with a condition that could have been detected, there is no clinic to hold accountable. The parties bear the risk themselves.

This is why documentation matters. Every test result should be in writing, dated, and shared between the parties. If there is a dispute later, the documentation is the only evidence that screening was done. A verbal assurance that "he got tested" is not worth anything if the relationship breaks down.

For guidance on the medical questions to ask a donor beyond the test results themselves, see our companion article on how to screen a known donor. For the legal framework that governs known donor arrangements in England and Wales, see legal agreements and contracts in known donor arrangements.