What is Congenital Varicella Syndrome (Congenital Chicken Pox)?
The varicella-zoster virus (VZV), more commonly known as the chickenpox virus, is a very infectious virus from the herpes family. Chickenpox is a common disease among children. Since the introduction of the chickenpox vaccine for all children in 1995, most adults in the United States and Europe are now immune to it. It’s thought that more than 90% of pregnant women are immune to this virus as they have the VZV antibody in their system.
However, those who don’t have the VZV antibody (seronegative patients) can still catch the chickenpox virus during pregnancy. This situation can be dangerous as it may lead to a severe lung condition called varicella pneumonitis, which can result in a higher chance of death. The virus also poses risks to the unborn baby, such as the possibility of the baby dying or developing severe health problems. These health problems include congenital varicella syndrome (damage to the embryo) or neonatal varicella (the baby contracting chickenpox or a widespread disease within the first 10 days of birth). Both of these conditions can result in serious health issues and even death.
What Causes Congenital Varicella Syndrome (Congenital Chicken Pox)?
The varicella-zoster virus (VZV) is a common virus found worldwide that can cause chickenpox and shingles. Anyone can get chickenpox by coming into contact with tiny droplets in the air that someone with the virus has breathed out, or by touching fluid from shingles sores.
Here’s how it works: the virus first multiplies in the respiratory tract, then spreads to nearby lymph nodes. From there, it finds its way into the bloodstream and spreads across the body. As the number of viruses in the body increases, new itchy blisters appear on the skin, generally numbering between 250 to 500 at different stages of development.
After someone is exposed to the virus, it can take anywhere from 10 to 21 days for the first symptoms to show up. Chickenpox often begins with fever, feeling unwell, stomach pain, and headaches. The person becomes contagious – that means they can spread the virus to others – one to two days before the rash breaks out and remains so until all blisters have crusted over. In pregnant women, the virus can pass through the placenta and infect the baby.
After someone gets over chickenpox, the virus doesn’t go away completely but instead hides in the body (in nerve cells) and can reactivate years later causing shingles. Shingles is typically accompanied by a painful blistering rash in an area determined by the affected nerve (dermatome) and can lead to lingering nerve pain (postherpetic neuralgia). Direct contact with shingles blisters can spread the virus, but this mainly happens in individuals who have a lower immune response or weakened immune systems. Shingles, however, does not pose a risk to unborn babies as they are protected by their mother’s immunity which passes to them through the placenta.
Risk Factors and Frequency for Congenital Varicella Syndrome (Congenital Chicken Pox)
Varicella, also known as chickenpox, is not a common issue during pregnancy because most women of childbearing age are already immune by having had chickenpox or the varicella vaccine (introduced in 1995). However, if a pregnant woman who is not already immune comes into direct contact with someone with chickenpox, either by contact with their skin lesions or respiratory droplets, she can become infected.
This infection can cause a condition known as Congenital Varicella Syndrome (CVS) in the baby if the mother is infected with the virus during the first half of her pregnancy. The greatest risk (2%) is between 13 and 20 weeks of gestation. There have been rare instances of CVS as late as 28 weeks. Since CVS was first described in 1947, approximately 41 cases per year occur in the US, 4 in Canada, and 7 in the United Kingdom.
If a pregnant woman catches chickenpox close to giving birth, her newborn may also get the infection. The virus can be passed from mother to baby in three ways: through the placenta, during delivery via contact with skin lesions or blood, and after birth by respiratory droplets or skin contact with infected lesions. Babies are at greatest risk if the mother gets chickenpox 5 days before and 2 days after delivery, this is when the baby will be exposed to the virus but won’t have enough time to get protective antibodies from the mother.
Signs and Symptoms of Congenital Varicella Syndrome (Congenital Chicken Pox)
Congenital Varicella Syndrome is a condition that can affect several parts of the body like the skin, limbs, eyes, and both the central and autonomic nervous systems. Skin lesions known as cicatrix, scarring in a unique pattern along the body, are a characteristic sign of this syndrome. Other defects may include underdevelopment or malformation of limbs and digits, eye conditions like chorioretinitis, cataracts, and nystagmus, brain abnormalities resulting in seizures and mental delays, and problems with the nervous system that can lead to issues like a neurogenic bladder, kidney swelling, esophageal dilation, and acid reflux.
Babies born to mothers who have varicella, a high-risk disease, typically appear healthy at first. However, if they do show symptoms, they often display classic skin lesions. There’s also a risk of more serious conditions spreading throughout the body, including pneumonia, hepatitis, meningitis and brain inflammation, as well as serious blood clotting issues due to liver failure and low platelet count.
- Scarring skin lesions known as cicatrix
- Underdeveloped or malformed limbs and digits
- Eye defects (chorioretinitis, cataracts, nystagmus)
- Brain abnormalities (seizures and mental delay)
- Nervous system problems (neurogenic bladder, kidney swelling, esophageal dilation, acid reflux)
- Potential for severe conditions (pneumonia, hepatitis, meningitis and brain inflammation, serious blood clotting issues)
Testing for Congenital Varicella Syndrome (Congenital Chicken Pox)
When it comes to congenital varicella syndrome (a condition that happens when a mother has chickenpox early in her pregnancy), testing the baby’s blood or the fluid in the womb isn’t very reliable. To find serious signs of a chickenpox infection in the unborn baby, doctors often use prenatal ultrasounds. These scans could show signs like unevenly short or malformed limbs, unusual tissue densities in the intestines and liver, slowed growth of the baby inside the womb, abnormalities in the baby’s brain (like increased fluid or undersized head), and even serious issues like excessive fluid in the fetus or the baby’s death.
As for a new mom who has chickenpox (known as neonatal varicella infection), it’s important to verify that the mother is indeed carrying the virus. Usually, pregnant women with chickenpox have clear symptoms like a scattered, blister-like rash that develops in different stages. If a doctor isn’t sure, they can gently scrape the base of one of the skin blisters for testing under fluorescent light or for a technique known as PCR (which can identify the virus’s genetic material). Viruses can also be grown from these samples, but this often takes up to a week for results. Any questionable skin blisters on the baby’s body should also be tested this way.
Treatment Options for Congenital Varicella Syndrome (Congenital Chicken Pox)
Cardiovascular problems in newborns can be a result of damage while the baby is still in the womb. These problems are usually untreatable after birth, as they develop even before the baby is born. However, when newborns show signs of active infection, a medicine called acyclovir can be given through an IV. The length of this treatment depends on when new skin lesions stop forming or when tests for the virus that causes chickenpox and shingles turn negative.
If a mother gets chickenpox during a critical period (five days before to two days after giving birth), her baby should receive a certain kind of treatment right after birth, or as soon as the mother starts showing symptoms if she gets chickenpox in the two days after delivery. This treatment, Varicella-zoster immune globulin (VZIG), helps to fight off the virus. If VZIG is not available, intravenous immune globulin (IVIG) can be used instead. Even if the mother has been treated with VZIG, newborns should still receive their own treatment. These newborns are monitored closely, and if they show signs of chickenpox, they should be treated quickly with intravenous acyclovir.
What else can Congenital Varicella Syndrome (Congenital Chicken Pox) be?
In addition to Zika, doctors need to consider other infections that can be passed from mother to baby during pregnancy or birth. These include:
- Cytomegalovirus (CMV): Newborns with CMV may have a smaller head than average, calcium deposits in the brain, large fluid-filled areas in the brain, eye inflammation, hearing loss, and small red skin spots.
- Herpes Simplex Virus (HSV): This infection can be identified by a blister-like skin rash or a severe infection that includes liver problems and blood clotting issues. The baby is often born to a mother who had active genital herpes sores during delivery.
- Rubella: Newborns with this disease often have cataracts (clouding of the lens in the eye) and heart defects.
- Toxoplasmosis: Signs of this infection can include inflammation of the eyes, too much cerebrospinal fluid in the brain causing pressure (hydrocephalus), calcium deposits in the brain, and a rash with red spots and bumps.
Doctors must be cautious and consider these conditions while diagnosing a baby.
What to expect with Congenital Varicella Syndrome (Congenital Chicken Pox)
The overall outlook for babies born with congenital varicella syndrome, a disorder caused by chickenpox in the mother during pregnancy, is often poor. Approximately 30% of affected infants unfortunately die within their first month of life. Early death often happens due to uncontrollable gastrointestinal reflux, serious recurrent pneumonia, and respiratory failure.
In the case of babies with varicella infection acquired after birth, if left untreated, the death rate is around 31%, often caused by severe pneumonia brought on by varicella. However, if the infants receive the necessary treatment using VZIG, which is a specific type of medication for this condition, the death rate decreases to around 7%.
Possible Complications When Diagnosed with Congenital Varicella Syndrome (Congenital Chicken Pox)
Both inborn chickenpox condition and chickenpox infection in newborn babies can lead to a high death rate. Babies who manage to survive can go on to experience infantile shingles within their first or second year of life, even if they haven’t had the primary chickenpox infection.
Preventing Congenital Varicella Syndrome (Congenital Chicken Pox)
Before getting pregnant, a woman’s immunity to the varicella-zoster virus (VZV), also known as chickenpox, should be checked. This can be done by looking at the woman’s medical history to see if she has had chickenpox or has had two doses of the vaccine. If neither of these is the case, a blood test for VZV antibodies should be performed. Women who could potentially become pregnant and haven’t built immunity should be informed about the dangers of getting chickenpox during pregnancy.
Those who aren’t pregnant and haven’t built immunity should ideally get two doses of the chickenpox vaccine, spaced four to eight weeks apart. However, since it’s a live vaccine and we don’t know how it affects the development of the fetus, it should not be administered during pregnancy. It’s safe to give the vaccine right after childbirth; even women who are breastfeeding can receive it. Getting vaccinated to avoid VZV infection is crucial to prevent complications in newborn babies.
