What Does CMV-Positive Mean When Choosing a Sperm Donor?

Short answer: A CMV-positive sperm donor usually has antibodies showing that he was exposed to cytomegalovirus in the past. It does not automatically mean that he has an active infection or that his sperm cannot be used. The fertility clinic should review whether the result reflects past exposure or active infection, the CMV status of the person who will carry the pregnancy, and the clinic's own policy before treatment.

What is CMV?

Cytomegalovirus, commonly called CMV, is a widespread virus in the herpesvirus family. Many healthy people acquire it without noticeable symptoms. After infection, CMV remains in the body and can sometimes reactivate.

CMV matters in pregnancy because a pregnant person can pass the virus to the fetus. The greatest concern is generally a first CMV infection during pregnancy, although reinfection or reactivation can also occur. This is why sperm-donor programs and fertility clinics evaluate CMV results as part of infectious-disease risk management.

Why are sperm donors tested for CMV?

The U.S. Food and Drug Administration regulates donated reproductive tissue, and sperm donors are tested for CMV as part of donor screening. The American Society for Reproductive Medicine also addresses CMV IgG and IgM testing in its guidance for sperm donation.

Testing does not eliminate every possible infectious risk. It helps sperm banks and clinics distinguish evidence of previous exposure from findings that could indicate a recent or active infection, and it supports appropriate counseling and consent.

What do IgG-positive and IgM-positive results mean?

• IgG-positive: This usually indicates past exposure to CMV and the presence of antibodies. An IgG-positive result alone does not prove an active infection.
• IgM-positive: This may be associated with a recent or active infection, but it is not interpreted in isolation. Confirmatory testing and clinical review may be needed.
• IgG-negative and IgM-negative: This generally means that antibodies were not detected at the time of testing and there is no laboratory evidence of prior exposure in those results.

ASRM guidance states that donors with evidence of active CMV infection should be excluded. Semen from a CMV-seropositive donor without active infection may be considered under appropriate clinical circumstances.

Does a CMV-positive donor have to be ruled out?

Not automatically. CMV is common, and a positive antibody result may reflect an infection that occurred long ago. ASRM states that using semen from a CMV-seropositive man without active infection is permissible when the person carrying the pregnancy is also CMV-seropositive, or after informed consent when she is CMV-seronegative.

That does not mean every clinic will accept every CMV-positive donor. Sperm banks and fertility clinics may use more restrictive policies, and the clinic performing IUI, IVF, or embryo transfer should approve the specific donor specimen before it is purchased or shipped.

If the recipient is CMV-negative, must the donor also be negative?

Some clinics prefer a CMV-negative donor for a CMV-negative recipient, while others may permit a donor with evidence of past exposure after counseling and informed consent. The appropriate choice depends on the donor's complete results, whether active infection has been excluded, the treatment plan, and the clinic's policy.

A profile label that simply says "CMV positive" may not provide enough information. Ask whether the result is IgG-positive, IgM-positive, or both, when the testing was performed, and whether repeat testing or quarantine requirements were completed.

What if a gestational surrogate will carry the pregnancy?

When donor sperm is used to create embryos for a gestational surrogate, the clinic still reviews the sperm donor's eligibility and infectious-disease records. The medical team should also determine which CMV testing or counseling is appropriate for the person who will carry the pregnancy.

The intended parent's CMV status does not replace the carrier's medical assessment. The fertility clinic should evaluate the complete arrangement before embryo creation or transfer and confirm that the donor specimen is acceptable for the planned use.

Does CMV status affect sperm quality or the child's genetics?

CMV status is an infectious-disease screening result. It is not a genetic trait, a genetic carrier-screening result, or a score for semen quality. Sperm quality is evaluated through semen testing, while inherited risks are assessed through medical history and genetic screening of the sperm and egg sources.

CMV is therefore only one part of donor selection. Intended parents should also review genetic compatibility, family medical history, donor identity options, vial type, treatment requirements, and future vial availability. See our guides to sperm-donor screening and choosing a sperm donor.

Questions to ask before buying donor-sperm vials

1. Is the donor CMV IgG-positive, IgM-positive, or both?
2. Has the sperm bank ruled out active CMV infection?
3. When was the donor tested, and was repeat testing completed?
4. What is the CMV status of the person who will carry the pregnancy?
5. Does the fertility clinic approve this specific donor and vial for the planned treatment?
6. Will additional counseling or informed consent be required?

The bottom line

A CMV-positive sperm donor is not necessarily infected now and is not automatically unsuitable. The key questions are whether the result reflects past exposure or active infection, what the recipient's or gestational carrier's CMV status is, and whether the fertility clinic approves the specimen after reviewing the complete records.

Expecting.ai can help intended parents compare donor profiles and organize the questions that matter before selection. Always obtain written confirmation from your fertility clinic before purchasing or shipping donor-sperm vials.

Authoritative sources

• ASRM: Gamete and embryo donation guidance
• FDA: What You Should Know - Reproductive Tissue Donation
• CDC: Clinical Overview of CMV and Congenital CMV

This article is for general educational purposes and does not replace individualized medical advice, laboratory interpretation, or approval from a fertility clinic.