Blog

When choosing a donor, you’ll likely consider a few criteria off the bat. A donor’s education, career, personality qualities, or ethnic background may be important in your selection. Another consideration as you begin your family-building process is CMV status.

What is CMV status, and why is it important?

CMV is short for cytomegalovirus, which is a common virus. It’s so common that over half of adults will have been infected with CMV by age 40. A first infection may result in flu-like symptoms or no symptoms at all. Once the body is infected with CMV, the virus lies dormant for life. CMV is in the cluster of Herpes, chickenpox, and mononucleosis viruses.

There is currently no vaccine for CMV, and many people won’t know they have it until a positive blood test. While CMV is usually not concerning in adults, for infants, CMV can be serious and cause life-long complications.

There is little to no risk of getting CMV from donor sperm, but because it’s impossible to rule out the chance completely, you may want to learn more about CMV status and factor it into your decision.

Should you use a CMV-negative or positive donor?

A donor’s CMV status will be either positive or negative. It’s important to know your CMV status if you plan to become pregnant before you choose a donor. If you are negative for CMV, meaning you do not have CMV antibodies, you will want your donor to be negative for CMV. With a negative status, you are vulnerable to CMV during pregnancy.

If you are positive for a prior CMV infection, you will likely ward off potential exposures. With a future pregnancy, there is a very low to no chance of passing the virus to the fetus. If your status is positive, you can use a donor with a positive or negative CMV status. A donor with a positive CMV status means that they are positive for a prior infection, not that they are positive for a current infection.

How do people contract CMV?

CMV spreads by coming into close contact with someone who has an infection. You can get CMV through sexual contact. Though it’s most commonly spread through direct contact, blood transfusions and organ transplants are additional ways to get CMV. CMV passes through bodily fluids such as:

• Tears
• Semen
• Urine
• Breast milk
• Saliva
• Blood
• Vaginal fluids

Some pregnant people will not know they have CMV. Testing for CMV during pregnancy involves two simple blood tests. You can ask your doctor for both. A CMV-IgG test screens for prior exposure to the virus. A CMV-IgM test indicates an active infection.

How can CMV affect pregnancy?

In pregnant people, CMV symptoms can include fever, swollen lymph nodes, sore throat, extreme fatigue, or no symptoms. CMV can be concerning due to the risk of passing it to the fetus or placenta. In severe cases, CMV can cause pregnancy loss.

If a pregnant person contracts a CMV infection, they have a 1 in 3 (33%) risk of passing it to the fetus. The risk of transmitting CMV to a fetus with a nonprimary infection, meaning a prior infection or infection with a new strain, is around 1%.

If you contract CMV during pregnancy, your obstetrician will closely monitor the fetus. Your provider can diagnose prenatal CMV by detecting CMV-DNA in amniotic fluid or fetal blood. If any findings indicate the effects of in-utero CMV, you may be referred to a specialist in high-risk obstetrics.

It’s important to know that only 1-4% of people develop a primary CMV infection during pregnancy. The risk of an infant developing complications is greatest if the pregnant person has a primary CMV infection in the first trimester.

CMV can also be passed to an infant during birth or nursing. A common period for CMV transmission is early childhood, which is a consideration if an expectant person is caretaking other young children or works at a school or daycare.

How can CMV affect babies?

When a baby is born with CMV, it’s called congenital CMV. CMV is the most common congenital viral infection. The risk of transmitting congenital CMV to a fetus from semen is extremely low, though not impossible.

One out of every 200 babies is born with a congenital CMV infection. Many babies with CMV are asymptomatic. According to the Centers for Disease Control and Prevention (CDC), one in five (20%) of babies born with congenital CMV will have long-term health problems; many of them will not. If an infant contracts a CMV infection postpartum, it’s unlikely they will experience any long-term complications.

There are a few categories of infants with congenital CMV: babies born with CMV who appear healthy, babies born who appear healthy and develop signs over time, and babies who are born sick. Babies who develop symptoms later may have hearing loss or a developmental delay. CMV is the most common cause of non-genetic hearing loss in infants and children.

For babies with congenital CMV who are born sick, symptoms can include:

• Premature birth
• Low birth weight
• Rash
• Jaundice (yellowing of the skin or eyes)
• Enlarged spleen or liver
• Seizures
• Microcephaly (small head)

For infants with congenital CMV, antiviral medication can treat the infection and prevent future complications.

Considering CMV status when choosing a donor

Many adults have a positive CMV status because of how common the virus is. At Fairfax Cryobank, we screen all sperm donors for CMV antibodies and screen semen samples using PCR (DNA testing) every three months. We also have a 6-month quarantine period to ensure accuracy. We are the only sperm bank that uses DNA testing for CMV. If a donor has an active infection, we destroy the sample.

Even though the risk of getting CMV from donor sperm is significantly low, knowing CMV status matters because you deserve to be the most informed during the family-building process. If you have questions about deciding on a donor’s CMV status, speaking with your provider can help determine the best action.