Do They Test for Varicella During Pregnancy? Understanding Varicella Zoster Virus (VZV) Screening
Whether they test for varicella during pregnancy depends largely on a woman’s previously documented immunity to the virus. Usually, the initial prenatal screening will involve a blood test to confirm if a woman is immune to varicella, ensuring appropriate management during the pregnancy.
Varicella Zoster Virus (VZV): A Brief Background
Varicella zoster virus (VZV), responsible for chickenpox (varicella) and shingles (herpes zoster), is a highly contagious virus. While most people contract chickenpox during childhood, it can pose significant risks during pregnancy. Congenital varicella syndrome, though rare, can lead to severe birth defects, and maternal varicella infection near delivery can cause serious neonatal varicella in the newborn. Therefore, determining a pregnant woman’s immunity is paramount.
Why Knowing Varicella Immunity Matters During Pregnancy
Knowing a woman’s varicella immunity status is crucial for several reasons:
- Protecting the Mother: Chickenpox during pregnancy can lead to pneumonia and other complications in the mother.
- Preventing Congenital Varicella Syndrome: If the mother contracts chickenpox during the first 20 weeks of pregnancy, the fetus is at risk of congenital varicella syndrome, a rare but serious condition.
- Preventing Neonatal Varicella: If the mother contracts chickenpox near delivery, the newborn may develop neonatal varicella, which can be life-threatening.
- Guiding Treatment Decisions: Knowing the immunity status helps healthcare providers determine the appropriate treatment options if a pregnant woman is exposed to or contracts chickenpox.
How Varicella Immunity is Assessed During Pregnancy
The primary method for assessing varicella immunity during pregnancy is a blood test called a varicella antibody test. This test checks for the presence of specific antibodies to VZV in the mother’s blood.
- Antibody Test: The blood test, usually part of a standard prenatal panel, detects varicella-specific IgG antibodies.
- Positive Result: A positive result indicates that the woman has antibodies and is considered immune, either from a previous infection or vaccination.
- Negative Result: A negative result means the woman does not have antibodies and is susceptible to varicella infection.
- Equivocal Result: Sometimes, the test result may be equivocal or indeterminate. In these cases, repeat testing may be recommended, or the woman may be presumed to be non-immune.
Managing Susceptible Pregnant Women
If a pregnant woman is found to be non-immune to varicella, certain precautions are taken:
- Avoid Exposure: The most important step is to avoid exposure to individuals with chickenpox or shingles.
- Varicella Zoster Immune Globulin (VZIG): If a non-immune pregnant woman is exposed to chickenpox, VZIG may be administered within 10 days of exposure. VZIG provides temporary protection by supplying antibodies against the virus. It does not prevent infection entirely but can reduce the severity of the illness.
- Vaccination Postpartum: Vaccination is recommended after delivery to protect the mother in future pregnancies. The varicella vaccine is a live attenuated vaccine and is contraindicated during pregnancy.
Common Misconceptions Regarding Varicella Testing During Pregnancy
Many misconceptions exist about varicella testing and management during pregnancy. Understanding these can help alleviate unnecessary anxieties.
- Misconception 1: Everyone is immune to varicella. While many adults are immune due to childhood infection or vaccination, not everyone has acquired immunity.
- Misconception 2: The varicella vaccine is safe during pregnancy. The varicella vaccine is a live attenuated vaccine and is contraindicated during pregnancy.
- Misconception 3: VZIG will completely prevent chickenpox after exposure. VZIG provides temporary protection and may reduce the severity of the illness but may not prevent it entirely.
Varicella Testing Compared to Other Pregnancy Screenings
Varicella antibody testing is often included as part of routine prenatal blood work, alongside other important screenings:
| Test | Purpose | Timing |
|---|---|---|
| Varicella Antibody Test | Determine immunity to varicella zoster virus (VZV) | Usually during the first prenatal visit |
| Rubella Antibody Test | Determine immunity to rubella (German measles) | Usually during the first prenatal visit |
| HIV Test | Screen for HIV infection | Usually during the first prenatal visit |
| Syphilis Test | Screen for syphilis infection | Usually during the first prenatal visit |
| Hepatitis B Surface Antigen | Screen for Hepatitis B infection | Usually during the first prenatal visit |
Frequently Asked Questions About Varicella Testing During Pregnancy
Is varicella testing mandatory during pregnancy?
No, varicella testing is not always mandatory, but it is strongly recommended as part of routine prenatal screening, especially if there is no documented proof of previous infection or vaccination. Individual doctors make this decision based on protocols and patient history.
What happens if I don’t know if I’ve had chickenpox or not?
If you are unsure whether you’ve had chickenpox or been vaccinated, the varicella antibody test will determine your immunity status. A blood test can confirm the presence or absence of antibodies.
Can I get the varicella vaccine while pregnant?
No, the varicella vaccine is not safe to administer during pregnancy. It is a live attenuated vaccine, which could pose a risk to the developing fetus. Vaccination is safe and recommended after delivery.
How accurate is the varicella antibody test during pregnancy?
The varicella antibody test is generally highly accurate in determining immunity. However, false negatives are possible, especially if the test is performed very soon after exposure.
What are the risks of getting chickenpox while pregnant?
Contracting chickenpox during pregnancy carries risks for both the mother and the baby, including pneumonia in the mother, congenital varicella syndrome in the fetus (if infected during the first 20 weeks), and neonatal varicella in the newborn if the mother is infected close to delivery.
What is Congenital Varicella Syndrome?
Congenital varicella syndrome is a rare but serious condition that can occur when a pregnant woman contracts chickenpox during the first 20 weeks of pregnancy. It can cause birth defects, including skin scarring, limb abnormalities, eye problems, and neurological problems.
What is Neonatal Varicella?
Neonatal varicella is a chickenpox infection in newborns whose mothers contract chickenpox shortly before delivery. It can be severe and even life-threatening, as the baby has not had time to develop protective antibodies.
What should I do if I’m exposed to chickenpox while pregnant and am not immune?
If you are exposed to chickenpox while pregnant and are not immune, contact your healthcare provider immediately. They may recommend Varicella Zoster Immune Globulin (VZIG), which can provide temporary protection.
How does VZIG work?
VZIG contains antibodies against the varicella-zoster virus. It provides passive immunity, which means it supplies pre-formed antibodies to help fight off the virus.
Is VZIG safe for pregnant women?
VZIG is considered safe for pregnant women. It is a human immunoglobulin product and does not contain live virus.
Can I breastfeed if I get chickenpox after giving birth?
Yes, you can usually breastfeed even if you get chickenpox after giving birth. However, it is important to take precautions to prevent the baby from getting infected, such as covering any chickenpox lesions and practicing careful hand hygiene. Consult with your healthcare provider for specific recommendations.
If I tested positive for varicella immunity during a previous pregnancy, do I need to be tested again in subsequent pregnancies?
Generally, if you have a documented positive varicella antibody test from a previous pregnancy, repeat testing is not usually necessary. However, your healthcare provider will review your medical history and determine if repeat testing is indicated based on individual circumstances.