Pregnant woman talking with doctor

For Healthcare Providers

Healthcare Provider Information and Resources

CMV can be a serious problem for babies who are infected before birth. This is referred to as congenital CMV and it occurs when a pregnant woman passes the virus to her unborn child. Congenital CMV can cause birth defects and developmental disabilities and more children will have disabilities due to congenital CMV than other well-known infections and syndromes, including Downs Syndrome, Fetal Alcohol Syndrome, Spina Bifida, and Pediatric HIV/AIDS. We have provided these resources for physicians, OB-GYNs, midwives, and nurses to enable better identification, prevention, and treatment for congenital CMV.

In the United States, approximately 1 to 4% of women will have their first, primary CMV infection during a pregnancy, and about 40% of these women who become infected with CMV for the first time during pregnancy will pass the virus to their babies. It is crucial that physicians and OB-GYN doctors share this information with women who are pregnant or preparing for pregnancy.

Looking for guidance on how to best counsel women about congenital CMV during pregnancy? The CDC offers a PDF download titled "CMV Facts for Pregnant Women and Parents" that may be helpful here.

About 1 out of every 200 babies (roughly 30,000 children annually) is born with congenital CMV making it the most common congenital viral infection in the United States. More than 6,000 children annually suffer permanent disability as a result. Severe complications from congenital CMV result in approximately 400 deaths nationwide per year.


Transmission of CMV is very rare through casual contact. CMV is spread from one person to another, usually by direct and prolonged contact with bodily fluids, including saliva, urine, and breast milk.

CMV is common among healthy children 1 to 3 years of age who attend daycare and can easily spread CMV among their peers. CMV is not generally harmful to these children and most kids will not show any signs or symptoms of infection.

Contact with the saliva or urine of young children is a major cause of CMV infection among pregnant women, especially mothers, daycare workers, preschool teachers, therapists, and nurses. Women who are pregnant or plan to become pregnant should practice standard hygiene procedures around young children to reduce their risk of CMV infection because the virus can be transmitted to her unborn child.

Signs/Symptoms of CMV in the Pregnant Patient

Most people who contract CMV will show no symptoms and may not even know that they have been infected. Others may develop a mild illness and may have any of the following symptoms:
  • High fever
  • Fatigue
  • General discomfort, uneasiness, or ill feeling
  • Joint stiffness
  • Muscle aches or joint pain 
  • Night sweats
  • Prolonged fever 
  • Sore throat
  • Swelling of the lymph nodes 
  • Weakness
  • Loss of appetite 
  • Weight loss
Since these are also symptoms of other illnesses, most people may not realize that they have been infected with CMV. If you have a pregnant patient experiencing symptoms similar to a seasonal illness, order a test for CMV IgM and IgG antibodies.

How to read CMV IgG and IgM lab results:

IgG negative + IgM negative = Not previously CMV infected, at risk for primary infection – Recommend CMV prevention precautions to your patient to help minimize their risk of contracting CMV during pregnancy. No further CMV antibody testing should be necessary unless the patient begins showing signs of a CMV infection or if the baby shows sign of a possible CMV infection during a routine ultrasound.

IgG positive + IgM positive = Recent CMV infection – Recommended that your patient delay conception until her CMV IgM antibody levels decline to an undetectable level and her CMV IgG avidity index climbs to a high favorable percentage. These results would show that her primary CMV infection has resolved itself and that there is minimal risk of CMV transmission to a new baby. It can take anywhere from 6 to 12 months for these CMV antibody and avidity tests to be favorable so that a woman can be safely ready to conceive without fear of passing her CMV infection to her baby. If your patient is already pregnant, consider extra ultrasounds to track the baby’s development in utero and to confirm that there are no prenatal signs of CMV infection. If the baby does show signs of CMV infection in ultrasound, an amniocentesis may be necessary to determine whether the baby has a CMV infection.

IgG positive + IgM negative = Past CMV infection that is not recent – Recommend that your patient practice CMV prevention recommendations during pregnancy. It is still possible that a recurrent CMV infection or an infection with a different strain of CMV can occur.

Signs/Symptoms of CMV in Utero

If your patient is believed to have contracted CMV during their pregnancy, regular ultrasounds and/or amniocentesis are the preferred methods to determine if CMV has been passed to the baby in utero. The CDC includes information about diagnosis, treatment and ongoing monitoring in their PDF download, "Diagnose, treat, and monitor children with Congenital Cytomegalovirus (CMV) to help improve their health outcomes"

Signs of CMV infection in utero include the following:
  • Placental thickening
  • Organomegaly - abnormal enlargement of organs
  • Hepatomegaly – abnormal enlargement of the liver
  • Splenomegaly – abnormal enlargement of the spleen
  • Pyelectasis - dilation of the renal pelvis, the funnel-like dilated proximal part of the ureter (muscular tubes that propel urine from the kidneys to the urinary bladder) in the kidney (also a marker for Down Syndrome)
  • Megaloureter – abnormal dilation of the ureter
  • Ascites - gastroenterological term for an accumulation of fluid in the peritoneal cavity (is a potential space between the parietal peritoneum and visceral peritoneum, that is, the two membranes that separate the organs in the abdominal cavity from the abdominal wall)
  • Fetal hydrops - accumulation of fluid in the fetal compartments
  • Abnormality of amniotic fluid
  • Microcephaly – small head circumference, more than two standard deviations smaller than average
  • Cerebral ventriculomegaly – dilation of the lateral ventricles of the brain
  • Intracranial calcifications - the build up of calcium salts in the soft tissue of the brain
  • Hyperdense image in thalamic arteries
  • Periventricular echodensities
  • Hepatic echodensities
  • Intestinal echodensities
  • Cystic structures in the germinal zone

Treating Congenital CMV During Pregnancy

If you have a pregnant patient who has been diagnosed with CMV during pregnancy, there are treatments and trials available. Recent studies indicate that Cytomegalovirus Immune Globulin Intravenous (CMV-IGIV) treatment may reduce the risk of congenital infection and/or disease in an unborn baby when given to pregnant women experiencing a primary CMV infection.

If you would like more information about clinical trials and the treatment options available to your patient during their pregnancy, please  contact us.

Signs/Symptoms of CMV in the Newborn

About 90 percent of babies born with congenital CMV will appear healthy at birth, and the vast majority will not have any visible symptoms or long-term issues. Many times, health problems or disabilities caused by congenital CMV infection can sometimes appear roughly two or more years after birth. Signs of CMV infection that may be present at birth:
  • Premature birth
  • Small size at birth
  • Small for Gestational Age (SGA)
  • Intrauterine Growth Restriction (IUGR)
  • Red or purple spots on the body caused by broken blood vessels (Petechiae / Purpura)
  • Yellow skin and eyes caused by increased bilirubin levels in the blood (Jaundice)
  • Liver problems
  • Lung problems
  • Spleen problems
  • Low blood platelet levels (Thrombocytopenia)
  • Small head size / small brain (Microcephaly)
  • Seizures
If your infant patient shows any of the signs and symptoms listed above, test the infant for congenital CMV infection using a saliva or urine PCR test. It is important to note that congenital CMV can only be accurately diagnosed if the newborn is tested within 21 days of life because after 3 weeks, it is hard to determine if the baby could have contracted the infection through nursing or by exposure to siblings or others who may be shedding the virus. Please refer to the CDC for additional information regarding interpreting laboratory tests.

Treating Congenital CMV in Newborns

Emerging research shows that antiviral drugs, Ganciclovir or Valganciclovir, may help newborns born with symptomatic congenital CMV. These antiviral treatments may prevent or lessen the severity of hearing loss and may improve head and brain growth. Ganciclovir and Valganciclovir can also help combat immediate medical concerns caused by CMV, such as thrombocytopenia, organ failure (most commonly spleen and/or liver), hepatitis, and pneumonitis. Treatments generally last from six weeks to six months and are administered orally or through an IV or PICC line.

Both Ganciclovir and Valganciclovir can have serious side effects, so be sure to consult with a doctor before and during the treatment period. Newborns receiving these antiviral treatments should have their regular blood counts taken to avoid problems with severe neutropenia  or anemia.

If you have a newborn patient born with congenital CMV and you would like more information about antiviral treatments, please contact us. Ongoing Interventions & Therapies If you have a newborn patient diagnosed with congenital CMV, be sure to refer the patient to have their hearing and vision checked regularly to identify any early onset of hearing or vision loss. Early diagnosis is critical to experiencing long-term developmental successes.

If you are concerned about potential seizure activity in the newborn, ask the parent to record the baby’s behavior for your review. They may need to schedule a consult with a pediatric neurologist. Additional monitoring, including EEG, may be suggested to properly diagnose whether the child is experiencing seizures.

Refer your newborn patients born with congenital CMV to your local Early Intervention (EI) program to determine whether the child should be evaluated for EI services.

To find out months and years down the road that this virus is common but preventable makes me so angry sometimes, but so happy to know that the education I have received now, can prevent other families for enduring what we have.
— Erica, Mother