About Cytomegalovirus (CMV): The Most Common Cause of PMG
According to Dr. William B. Dobyns, one of the leading researchers who studies PMG as well as other brain malformations, the most common cause of PMG, by far, is related to prenatal infection from Cytomegalovirus (CMV). CMV is a herpes type of virus that is very common and is typically harmless to the general population.
The National CMV Network at www.nationalcmv.org states the following information:
According to the Centers for Disease Control and Prevention (CDC), out of every 100 Americans, 50- 80 people will have had a CMV infection by the time they are 40 years of age. A CMV infection causes cold-like symptoms, such as sore throat, fever, fatigue and swollen glands. These mild Cytomegalovirus symptoms last for only a few short weeks and is rarely a cause for concern for healthy kids or adults. The symptoms are sometimes so mild, only resembling a common cold, that most people do not even know they have it. These mild Cytomegalovirus symptoms last for only a few short weeks and is rarely a cause for concern for healthy kids or adults. Once the CMV virus is in the persons body, it stays there for life.
Types of CMV Infections
Primary – A “Primary CMV Infection” is when a person contracts CMV for the very FIRST time. People with Primary CMV Infection will have no pre-existing immunity to the virus. For a pregnant mother, this is the most critical situation because her body has had no opportunity to make antibodies (the body’s natural immune system) against the virus. Because the unborn baby’s immunity comes from the mother, the infection is much more significant to the pregnant mother and unborn child.
Recurrent – A “Recurrent CMV Infection” is when a previous CMV infection that has been considered dormant becomes active again. Because the body has already built up antibodies or a pre-existing immunity to the virus, it will rarely cause any noticeable symptoms. A CMV infection can be brought on again when a persons immune system is down because of issues with elevated stress, disease, hospitalizations or certain therapeutic drugs.
If a woman is pregnant and becomes infected with the virus again, her body has already built up an immunity to the virus, thus, making it easier to protect the baby from the more serious complications that you would get with a “Primary CMV Infection.”
CMV and Pregnancy
CMV can cause critical problems for babies who are infected in the womb. This is referred to as Congenital CMV. It occurs when a infected mother passes the virus to her unborn child through the placenta, causing birth defects and developmental disabilities.
In the United States, approximately one to four percent of (1-4%) of uninfected women have a Primary CMV infection during a pregnancy, and approximately 40% of women who become infected with CMV for the first time during pregnancy pass the virus to the unborn child.
Congenital CMV affects one in every 150 babies born each year, making it the most common Congenital Viral Infection in the United States. That is approximately 30,000 children annually!! Of that statistic, one in every five children born with Congenital CMV will develop permanent health problems with as many as 400 infant deaths annually.
Congenital CMV infection is arguably the most common PREVENTABLE cause of neonatal disability in the United States. More children are being born with disabilities due to Congenital CMV than any other well-known infections and syndromes, including Downs Syndrome, Fetal Alcohol Syndrome, Spina Bifida, and Pediatric HIV/AIDS.
Nearly 90% of infants born with Congenital CMV appear healthy at birth, and the vast majority will not have any visible symptoms or long term issues. Health problems or disabilities caused by Congenital CMV infection can sometimes appear roughly two or more years after birth. Infants and children who are infected with CMV after birth rarely present with symptoms and will not be exposed to any permanent problems or disabilities.
It is extremely disturbing that there are NO standard warnings for pregnant women who may come down with “severe cold” symptoms or “mononucleosis-like illness” during pregnancy to be tested for the CMV Virus. There are NO mandates from the Centers for Disease Control and Prevention (CDC), the NIH, or the American College of Obstetricians and Gynecologists (ACOG) to test for CMV or to warn pregnant women of the potential risks of CMV to their unborn children. In fact the National CMV Foundation stated that only 9% of women know about CMV. This is frightening and must change!
As of right now, only 86% of OB/GYNs who reported ever testing for CMV during pregnancy, did so ONLY because their patients requested a test or because a fetal anomaly was identified during ultrasound. www.cdc.gov/mmwr/preview/mmwrhtml/mm5703a2.htm
CMV Screening and Testing
Every woman of childbearing age should know her CMV status! Unfortunately, if you are reading this, you or your child may have already been diagnosed or have seen the consequences of a CMV infection. But for those who are planning to conceive or maybe you are considering having another child, KNOW YOUR RISK! Before you plan to conceive, ask you doctor to have a blood sample drawn for a CMV IgG and IgM antibody tests. (for more information on what these tests are, please visit www.nationalcmv.org/resources/glossary.aspx#cmvigg.
Women can be tested for CMV prior to pregnancy! Ask your doctor to run CMV IgM and IgG antibody tests. If a woman has been exposed to a recent CMV infection it is recommended that she wait until her CMV IgM antibody levels decline to an undetectable level, and her CMV IgG avidity index climbs to a highly favorable percentage, BEFORE trying to conceive. This can take anywhere form six to twelve months. It is highly recommended to wait until the CMV infection has resolved itself because it minimizes the risk of CMV transmission from the pregnant woman to her baby in utero.
If you are already pregnant, you can request that CMV IgM and IgG antibody lab tests be added to your routine labs. These tests are relatively inexpensive and are covered by most insurance plans. If a pregnant woman IS diagnosed with CMV during her pregnancy, her doctor should perform an amniocentesis to determine whether Congenital CMV has passed to her unborn baby.
CMV Treatment Options
Currently, several medications are undergoing clinical trails or are licensed for the treatment and possible mitigation of the effects of Congenital CMV. For pregnant women who have transmitted a “Primary CMV Infection” to their baby, administration of Cytogam, a CMV hyperimmune globulin, may lessen or reverse CMV symptoms in utero. For newborns who are already showing symptoms of being infected, there are antiviral treatments that MAY be beneficial.
There is no available vaccine for preventing Congenital CMV infection. However, a few CMV vaccines are being tested in humans, including live attenuated (weakened) virus vaccines and vaccines that contain only pieces of the virus. The Institute of Medicine has ranked the development of a CMV vaccine as a highest priority because of the lives it would save and the disabilities it would prevent. It may be a number of years before there is a FDA approved CMV vaccine. See more at www.cdc.gov/cmv/overview.html and www.nationalcmv.org/cmv-research/vaccines-clinical-trials.aspx
What We Can Do
Many experts believe that a CMV vaccine is possible within the next 10 to 20 years, but a CMV vaccine is unlikely to occur without the awareness and support of the general public. The best thing we can do to help is to become knowledgeable about CMV and its risks, share what you have learned with everyone you know and encourage people to REQUEST to be screened for CMV before becoming pregnant. Hopefully, one day, a CMV screening will be a routine test given to all women wishing to become pregnant and we can STOP CMV in its tracks before it causes any more catastrophic effects to our children.