New information about Zika may become available before it can be included in this fact sheet. Please contact a MotherToBaby Service for additional information that may be available.
In every pregnancy a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure to the Zika virus may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.
What is Zika? How do people get it?
Zika is a virus that is usually spread through bites from infected mosquitoes. Not all mosquitoes carry the Zika virus and not every person bitten by an infected mosquito will get Zika. People who have the highest risk of getting the Zika virus are those who live in or travel to areas with active Zika transmission.
Other ways people become infected with the Zika virus include sexual contact with an infected partner (vaginal, anal or oral sex, or sharing of sex toys), from an infected pregnant woman to her fetus, and through blood transfusions with infected blood. Blood donations in the U.S. are screened for Zika virus. There is no evidence that Zika is spread through the saliva or by coughing or sneezing.
What are the symptoms of Zika virus?
Four out of 5 people who are infected with the Zika virus do not have symptoms. Those who do develop symptoms usually have a mild flu-like illness with fever, rash, headache, joint and/or muscle pain and conjunctivitis (“pink eye”). Symptoms can begin 3-7 days after being infected and can last for several days to a week.
Can the Zika virus affect my pregnancy?
Yes. If a woman is infected with Zika virus during pregnancy, there is a chance the virus will pass to the developing baby. If this happens, it can increase the risk of microcephaly (small head and brain) and other severe brain defects. It may also cause eye defects, hearing loss, and problems with the joints and limb movement. This pattern of birth defects caused by Zika infection in pregnancy is called ‘congenital Zika syndrome.’ Zika infection in pregnancy might also affect the baby’s growth or increase the chance of miscarriage or stillbirth. Sometimes, a baby can be born with no apparent effects from Zika infection, but can later have slowed head and brain growth as a result of the infection (called postnatal microcephaly).
Researchers are still working to find out how likely it is that a baby exposed to Zika in pregnancy will have congenital Zika syndrome, or if it makes a difference when in the pregnancy the mother becomes infected. Based on limited research, it is possible that infection early in pregnancy could be a greater risk to the baby than infection in later pregnancy. But Zika virus is still considered a risk at any time during pregnancy.
Are there other health problems that having Zika virus can cause?
Yes. People who have been infected with Zika virus have a small increased risk for developing Guillain-Barré syndrome (GBS). GBS is a rare condition affecting a person’s nervous system, leading to weakness or causing the person to not be able to move certain parts of their body (paralysis). Symptoms of GBS can last a few weeks to several months. Most people who develop GBS completely recover, but some can have permanent nerve damage.
How is Zika treated?
A person with Zika can treat the symptoms, such as fever, headache, joint pain, pink eye, and any other symptoms that might develop. There is no cure, medication or vaccine specific for Zika. Even if an infected person treats their symptoms, they can still pass the virus to others through sex or to a developing baby in pregnancy.
How can I protect myself from the Zika virus?
Avoid traveling to areas with active Zika transmission (areas where mosquitoes are spreading the virus). For a list of areas with active Zika transmission, visit the Centers for Disease Control and Prevention (CDC) webpage Zika Travel Information.
Avoid mosquito bites by using insect repellents approved by the Environmental Protection Agency (EPA), wearing protective clothing (such as long sleeves and long pants and/or clothing treated with the insecticide permethrin), and emptying any standing water from around your home, as this is where mosquitoes lay their eggs. When possible, use air-conditioning or screens to keep mosquitoes out of the house. For more information on prevention, visit the CDC webpage Zika Virus Prevention. MotherToBaby fact sheets are available for DEET and Insect Repellents and Pregnancy.
Since the Zika virus can be spread through sexual contact, you can protect yourself by not having sex with a partner who might have the virus. If you do have sex with a partner who might be infected, use barrier protection (male and female condoms and dental dams) correctly from start to finish every time you have sex. For more information, visit the CDC webpage Protect Yourself During Sex.
I am pregnant. What if my partner or I have traveled, or need to travel, to a Zika-affected area?
The CDC recommends that pregnant women and their sexual partners avoid travel to areas where mosquitoes are infected with Zika. For a list of these areas, visit the CDC webpage visit the Centers for Disease Control and Prevention (CDC) webpage Zika Travel Information.
If a pregnant woman must travel to a Zika-affected area, she should avoid mosquito bites and talk to her healthcare provider about being tested for Zika when she gets back. If her partner travels, they should not have sex, or should use barrier protection every time for vaginal, anal or oral sex, for the rest of the pregnancy. Pregnant women and their sexual partners who live in Zika-affected areas should also follow this advice for the rest of the pregnancy. See the CDC webpage Protect Yourself During Sex.
I am thinking about getting pregnant. How long do I need to wait after being in a Zika-affected area or having sex with someone who might be infected?
Women who might have been exposed to the Zika virus through travel or sex should wait at least 8 weeks before trying to get pregnant, even if they don’t have symptoms of Zika. Men who might have been exposed to the Zika virus through travel or sex should wait at least 6 months before trying to conceive a pregnancy, even if they do not have symptoms. During any wait time, men and women should use barrier methods and effective birth control to prevent pregnancy and to protect their sexual partners from the virus. Visit the CDC webpage Women Trying to Become Pregnant for more details.
I had Zika virus months ago. Is there a risk of birth defects for my future pregnancies?
Waiting at least 8 weeks after Zika infection allows time for the virus to clear from a woman’s body before she gets pregnant. After that time, there is no increased risk of Zika-related birth defects in future pregnancies. Based on what we know about other similar viruses, it is unlikely that someone could get Zika virus again after having it once.
Is there a test that can tell if I have or have had the Zika virus?
Yes. The kind of test that may be right for you depends on if and when you had symptoms and whether or not you are pregnant. Not everyone who may have been exposed to Zika virus needs to be tested. Your healthcare provider and your local health department can decide if testing is right for you. Guidelines for testing pregnant women and their sexual partners can be found on the CDC webpage Interim Guidance for Health Care Providers.
What if I am pregnant and test positive for Zika, or if my test results are not clear?
The CDC provides guidance to healthcare providers for following the baby’s growth and development for the rest of the pregnancy (see Interim Guidelines for Healthcare Providers). This may include more frequent ultrasounds (called serial ultrasounds) every 3–4 weeks and prenatal diagnostic tests to look for Zika infection in the baby. It is important to remember that just because a pregnant woman tests positive for Zika, it does not automatically mean her baby will have birth defects.
If I tested positive for Zika, can the baby be checked for Zika virus infection at birth?
Yes. The CDC recommends testing the blood of newborns whose mothers have confirmed or possible Zika virus infection, and closely monitoring their growth and development (see Interim Guidelines for Healthcare Providers). Discuss testing options and recommendations for your baby’s care with your healthcare provider.
Can I breastfeed if I have the Zika virus?
At this time, the CDC has not identified any cases of infants being infected with Zika virus through breast milk. Experts believe the benefits of breastfeeding outweigh any potential risks of Zika virus infection through breastfeeding. Be sure to talk to your health care provider about all your breastfeeding questions.
I got bit by a mosquito in the United States. Could I now be infected with the Zika virus?
The two main types of mosquitoes that can carry the Zika virus (Aedes aegypti and Aedes albopictus) live in many countries worldwide, including parts of the United States (U.S.). Both kinds are common in the southern half of the U.S., while the Aedes albopictus are also found in the Midwest and most of the northeastern states. The mosquitoes are not born with Zika, but can become infected by biting someone who has Zika.
In 2016, the CDC reported several small, local outbreaks of Zika virus in areas of Florida and Texas. These areas are no longer seeing new cases of local infection. As of now, no other places in the U.S. have reported locally-acquired cases. For the most updated information, visit Maps of Zika in the United States or call MotherToBaby toll-free at 1-866-626-6847.
Are there still precautions in place for areas of Florida or Texas?
Currently, Miami-Dade County, FL and Brownsville, TX are still considered areas of caution for Zika virus infection. Couples who are pregnant or planning a pregnancy should consider following the same precautions for these areas as they would for areas with active transmission. For more information, see Advice for People Living In or Traveling to South Florida and Advice for People Living In or Traveling to Brownsville, TX.
Where can I get more information on the Zika virus?
- World Health Organization: http://www.who.int/mediacentre/factsheets/zika/en/
- Pan American Health Organization: http://www.paho.org/hq/index.php?option=com_content&view=article&id=11585&Itemid=41688&lang=en
- Deet: https://mothertobaby.org/fact-sheets/deet-nn-ethyl-m-toluamide-pregnancy/pdf/
- Insect Repellents and Pregnancy: https://mothertobaby.org/fact-sheets/insect-repellents/pdf/
- From the CDC:
- Zika Virus Prevention: http://www.cdc.gov/zika/prevention/index.html
- Zika Travel Information: http://wwwnc.cdc.gov/travel/page/zika-information
- Protect Yourself During Sex: http://www.cdc.gov/zika/prevention/protect-yourself-during-sex.html
- Women Trying to Become Pregnant: http://www.cdc.gov/zika/pregnancy/women-and-their-partners.html
- Pregnant Women: http://www.cdc.gov/zika/pregnancy/protect-yourself.html