Última actualización:
4/9/2025
Años publicados: 1997, 2005, 2025
NORD gratefully acknowledges Gioconda Alyea, MD (FMG), MS, National Organization for Rare Disorders, for assistance in the preparation of this report.
Advertisement
Introduction
Congenital varicella syndrome (CVS) is a very rare disorder in which affected babies have distinctive abnormalities at birth because their mother had a chickenpox (maternal varicella zoster) infection early in her pregnancy.1
The varicella-zoster virus (VZV), a type of herpesvirus that can infect many different parts of the body, causes chickenpox when someone is first infected. It’s very contagious and spreads through coughs, sneezes, or contact with the fluid from chickenpox blisters. After someone recovers from chickenpox, the virus does not go away completely. It stays inactive in the body and can reactivate later in life as shingles, which causes a painful rash.2
Pregnant females who are not immune to the VZV have higher risks if they catch the virus. They’re more likely to develop a serious lung infection called varicella pneumonitis, which can cause lung inflammation and respiratory distress that can be life-threatening.2
When the virus passes to the baby during pregnancy, it can lead to miscarriage, stillbirth, or to congenital varicella syndrome (CVS) if the baby is infected between 8 and 20 weeks of pregnancy. Babies with CVS may be born with birth defects like scars on their skin, underdeveloped arms and legs, and problems with their brain, eyes, and/or, in rare cases, other areas of the body.3,4
In many cases of congenital varicella syndrome, abnormal growth delays occur during fetal development (intrauterine growth retardation).4
If the mother gets chickenpox within five days before giving birth (delivery) or two days after delivery, the newborn can develop neonatal varicella, a severe form of chickenpox. Because a newborn’s immune system is so fragile, this can cause serious illness and even death.3
For people planning a pregnancy, checking immunity to VZV and getting vaccinated if needed, can help prevent these complications and keep both mother and baby safe.
The signs and symptoms of congenital varicella syndrome (CVS) may include:2,3,6
If a mother gets chickenpox right around the time of delivery, specifically 5 days before to 2 days after birth, the newborn has the highest risk of developing neonatal varicella, a severe and sometimes life-threatening form of the disease.3
Newborns with neonatal varicella might look healthy at first, but symptoms usually appear within a few days. These babies often develop a typical chickenpox rash with small, fluid-filled blisters. In severe cases, the infection can spread throughout the body, causing pneumonia, liver inflammation (hepatitis), brain swelling (meningoencephalitis) and blood clotting problems (coagulopathy) due to liver failure and low platelet counts.2 Fetal death can occur if the fetus is severely affected.7
Congenital varicella syndrome (CVS) is caused by the varicella-zoster virus (VZV) when a female who is not immune to the disease gets infected during the first half of pregnancy. The highest risk is between 8 and 20 weeks (especially between 13 to 20 weeks), with about a 2% chance of the baby developing CVS if the mother gets chickenpox during this time.2
The pregnant female who is not immune to VZV catches the virus through direct contact with an infected person or by breathing in respiratory droplets from someone with chickenpox. The varicella zoster virus invades the fetal nerves (e.g., optic stalk, cervical cord, lumbosacral cord). This can lead to less nerve growth and/or damage to the nerve signals (denervation) to certain tissues.5
Babies with CVS may be born with birth defects like scars on their skin, underdeveloped arms and legs and problems with their nervous system.3
If the mother gets chickenpox within five days before delivery or two days after, the newborn can develop neonatal varicella, a severe form of chickenpox. Because a newborn’s immune system is so fragile, this can cause serious illness and even death.3
Neonatal infection may be caused by the virus traveling from the mother to the fetus through the placenta (transplacental transmission), exposure to the fluid inside blisters (vesicles) associated with VZV during delivery, or respiratory droplets. The risk of neonatal infection is lower if maternal chickenpox occurs early enough before delivery to allow for the transplacental transfer of protective anti-VZV antibodies.5
Shingles, which happens when the virus reactivates later in life, isn’t a risk to unborn babies. This is because mothers who are already immune pass protective antibodies to their baby through the placenta.2,3
In addition, pregnant females who are not immune are more likely to develop a serious lung infection called varicella pneumonitis which can be life-threatening. 2 For people planning a pregnancy, checking immunity to VZV and getting vaccinated if needed, can help prevent these complications and keep both mother and baby safe.
Congenital varicella syndrome is rare, with around 41 cases reported each year in the U.S., 4 in Canada and 7 in the U.K.2,6 In one study conducted in 2006 to 2009, the annual incidence of congenital varicella infection was 0.19 per 100,000 live births and the incidence of neonatal infection was 2 per 100,000 live births.6 If a pregnant female gets chickenpox, especially in early pregnancy (before 20 weeks), the baby has a small risk, about 1% to 2%, of developing congenital varicella syndrome. If a female gets chickenpox later in pregnancy (after 20 weeks), the risk of CVS drops significantly. Only 9 isolated cases have been reported between weeks 21 to 28.
Varicella infection during pregnancy is rare because most females of childbearing age are already immune, either from having chickenpox as a child or from getting the varicella vaccine, which became widely available in 1995. More than 90% of adults in the U.S. and Europe have immunity to VZV, meaning they’ve either had chickenpox or received the vaccine and are protected from getting it again. 2,5,6,7 Neonatal varicella infection is also very rare.7
If a pregnant female gets a widespread, itchy rash with fluid-filled blisters at different stages of healing, that’s usually enough to diagnose chickenpox. If the rash looks unusual, doctors may scrape a blister to test for the virus using a direct fluorescent antibody test or polymerase chain reaction (PCR) test, a lab test that looks for the virus’s genetic material. For babies showing signs of neonatal varicella, these same tests can be done on their skin lesions to confirm the diagnosis.2
Detecting congenital varicella syndrome before birth is difficult. Blood or amniotic fluid (the fluid in the womb around the baby) samples aren’t always reliable for identifying the infection. Instead, prenatal ultrasounds can look for signs like:2
Treatment
Administering the varicella vaccine before pregnancy effectively prevents varicella-related complications in mothers, fetuses and newborns.
If a baby is affected by congenital varicella syndrome (CVS), meaning the virus caused damage while the baby was still developing in the womb, antiviral treatments like acyclovir will not reverse that damage. This is because the harm happened during early development and the medicine cannot undo the damage. However, if the baby shows signs of an active chickenpox infection after birth, acyclovir should be given through an IV to control the virus. The treatment should continue until there are no new skin blisters or PCR confirms the virus is gone.2
If a mother contracts chickenpox between 5 days before and 2 days after delivery, the most dangerous time for the baby, because of the risk of neonatal varicella, the newborn should receive varicella-zoster immune globulin (Varizig) immediately after birth to provide passive immunity. Passive immunity is a type of immunity where someone is given antibodies for the infection, in this case this medication, instead of their body making antibodies. If Varizig is unavailable, intravenous immune globulin (IVIG) can be used instead.2,6
Pregnant females without evidence of immunity who have been exposed to varicella should receive Varizig as soon as possible, ideally within 96 hours, but it can be administered up to 10 days after exposure. This treatment is meant to lessen the severity of the disease.6
At risk females (for example, those without a confirmed history of varicella, documentation of receiving two doses of varicella vaccine, or laboratory evidence of immunity) who have had a significant exposure to a person with varicella or zoster are typically given medical treatments to help prevent an infection after the exposure (post-exposure prophylaxis).6
Varizig is an immunoglobulin product containing a high concentration of VZV-specific antibodies. In the United States, Varizig is the only available product with VZV-specific antibodies. Those exposed should be given Varizig within 10 days of exposure.2,6 Varizig is given intramuscularly, meaning directly into the muscle, with dosing based on body weight.
Therefore, immunoprophylaxis (post-exposure vaccination recommended for eligible individuals and Varizig for people ineligible for vaccination, like immunocompromised individuals, pregnant females and newborns) decreases the risk of having varicella after exposure and results in a milder illness in those who test positive for the disease when having a negative test before (seroconvert) despite post-exposure prophylaxis.6
So far, research hasn’t shown any long-term side effects from VZIG or acyclovir when used in newborns. Since these treatments can prevent severe, life-threatening illness, the benefits far outweigh any possible risks.2
Unfortunately, the prognosis for babies born with congenital varicella syndrome is poor. About 30% of affected babies don’t survive the first month of life, often due to severe complications like:2
With VZIG, the death rate drops to 7%.
Even if a baby survives congenital or neonatal varicella, they might still face challenges. One common issue is infant shingles (herpes zoster), a painful rash caused by the reactivation of the chickenpox virus that stays dormant in the body. Normally, shingles happens later in life, but these children can develop it within their first or second year, even though they never had a typical chickenpox rash.2,6
Information on current clinical trials is posted on the Internet at https://clinicaltrials.gov/ All studies receiving U.S. Government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY:Â (866) 411-1010
Email:Â [email protected]
Some current clinical trials also are posted on the following page on the NORD website:https://rarediseases.org/living-with-a-rare-disease/find-clinical-trials/
For information about clinical trials sponsored by private sources, contact:http://www.centerwatch.com/
For information about clinical trials conducted in Europe, contact:https://www.clinicaltrialsregister.eu/
4. Behrman RE, Kliegman RM, Arvin AM., eds. Nelson Textbook of Pediatrics. 15th ed. 1996:525-26.
NORD y la Fundación MedicAlert se han asociado en un nuevo programa para brindar protección a pacientes con enfermedades raras en situaciones de emergencia.
Aprende más https://rarediseases.org/patient-assistance-programs/medicalert-assistance-program/Asegurarse de que los pacientes y los cuidadores estén equipados con las herramientas que necesitan para vivir su mejor vida mientras manejan su condición rara es una parte vital de la misión de NORD.
Aprende más https://rarediseases.org/patient-assistance-programs/rare-disease-educational-support/Este programa de asistencia, primero en su tipo, está diseñado para los cuidadores de un niño o adulto diagnosticado con un trastorno raro.
Aprende más https://rarediseases.org/patient-assistance-programs/caregiver-respite/The information provided on this page is for informational purposes only. The National Organization for Rare Disorders (NORD) does not endorse the information presented. The content has been gathered in partnership with the MONDO Disease Ontology. Please consult with a healthcare professional for medical advice and treatment.
The Genetic and Rare Diseases Information Center (GARD) has information and resources for patients, caregivers, and families that may be helpful before and after diagnosis of this condition. GARD is a program of the National Center for Advancing Translational Sciences (NCATS), part of the National Institutes of Health (NIH).
View reportOrphanet has a summary about this condition that may include information on the diagnosis, care, and treatment as well as other resources. Some of the information and resources are available in languages other than English. The summary may include medical terms, so we encourage you to share and discuss this information with your doctor. Orphanet is the French National Institute for Health and Medical Research and the Health Programme of the European Union.
View report