Zika virus and pregnancy
If you get infected with Zika during pregnancy, you can pass it to your baby. It causes a birth defect called microcephaly and other brain problems.
What is Zika virus?
Zika is a virus that can cause serious problems during pregnancy. If you’re pregnant and infected with Zika virus, you can pass it to your baby. Zika infection during pregnancy causes a birth defect called microcephaly and other brain problems. It also may be linked to other serious problems for a baby.
Our Zika resources
How does Zika virus spread?
Zika virus spreads in several ways:
- Through mosquito bites. This is the most common way Zika spreads. You can get infected from a mosquito that carries the Zika virus, and a mosquito can get the virus by biting an infected person. The mosquito can then pass the virus by biting someone else. Zika infection usually stays in a person’s blood for a few days to a week after getting infected. The mosquito can’t pass the virus until 8 to 12 days after biting an infected person. The mosquitoes that carry Zika virus can live both inside and outside. They’re called day biters because they bite most often during the day, but they also bite at night.
- By passing it to your baby during pregnancy. More research is needed, but experts think Zika virus can pass through the placenta to your baby. The placenta grows in your uterus (womb) and supplies your baby with food and oxygen through the umbilical cord.
- Through sex with an infected person. During sex, an infected male can pass Zika through semen. Zika stays in a man’s semen for at least 2 weeks and possibly more than 3 months after his signs and symptoms start. Semen contains sperm, which is what fertilizes an egg to get a woman pregnant. An infected woman can pass Zika to her partner during sex through vaginal fluids or blood from her menstrual period. Zika has been found in a woman’s cervical mucus up to 11 days after her signs and symptoms start. Cervical mucus is a body fluid that collects in the vagina.
- Through a blood transfusion with infected blood. A blood transfusion is when you have new blood put into your body.
- Through laboratory exposure in a health care setting
The Centers for Disease Control and Prevention (also called CDC) has maps that show where Zika is spreading (also called Zika outbreaks or Zika-affected areas) in the United States and around the world. You can see the maps at cdc.gov/zika.
Zika-affected areas include:
- The United States and its territories, including Puerto Rico. Zika is spreading by mosquitoes in the Wynwood and Miami Beach areas of Miami, Florida. The CDC says pregnant women and their partners who are worried about being exposed to Zika may want to postpone travel to all parts of Miami-Dade County unless it’s absolutely necessary.
- North, Central and South America
- Pacific Islands
How can you protect yourself and others from Zika virus?
There’s no vaccine to help prevent the Zika virus. Researchers are working to develop a Zika vaccine, but it may not be available to the public for 1 to 2 years. If you’re pregnant or trying to get pregnant, here’s what you and your partner can do to protect yourselves from Zika:
- Don’t travel to a Zika-affected area unless you absolutely have to. If you do visit these areas, talk to your health care provider before you travel and take steps to prevent mosquito bites during your trip. Check CDC travel alerts for updates.
- Prevent mosquito bites. See the information below about how to protect yourself and your family.
- Don’t have sex with a male or female partner who may be infected with Zika virus or who has recently travelled to a Zika-affected area. If you do have sex, use a barrier method of birth control every time. Barrier methods keep a man’s sperm from reaching a woman’s egg, and some help protect against sexually transmitted diseases (also called STDS). Barrier methods include condoms (male or female) and dental dams. A dental dam is a square piece of rubber that can help protect you from STDs during oral sex.
- If you work in a hospital, doctor’s office, lab or other health care setting, follow your workplace safety rules. Wear gloves, a gown, a mask and goggles. Don’t have direct contact with body fluids and lab samples that may be infected with Zika virus. After direct contact with infected patients, fluids or lab samples, wash your hands well with soap and water or use a hand sanitizer with 60 percent alcohol in it. Follow safety rules for throwing out needles and other items that may have body fluids on them.
- If you have or may have Zika, wait at least 4 weeks before donating blood and don’t donate umbilical cord blood (also called cord blood). Cord blood is the blood in the umbilical cord and placenta after your baby is born and the cord is cut. It’s possible that Zika may spread through cord blood.
Here’s how you can prevent mosquito bites:
- Use an insect repellant (a product that keeps insects from biting you), like bug spray or lotion, that’s registered with the Environmental Protection Agency (also called EPA). All EPA-registered bug sprays and lotions are checked to make sure they’re safe and work well. Make sure the product contains one or more of these substances that are safe to use during pregnancy and breastfeeding: DEET, picaridin, oil of lemon eucalyptus, para-menthane-diol and IR3535. If the product contains DEET, make sure it has at least 20 percent DEET. Always follow the instructions on the product label. Most bug sprays and lotions are safe to use on babies 2 months and older, but don’t use products that contain oil of lemon eucalyptus or para-menthane-diol on children younger than 3 years. Don’t put bug spray or lotion on your skin under clothes. If you use sunscreen, put it on first before the spray or lotion.
- If you’ve been in a Zika-affected area, use bug spray or lotion for 3 weeks after you get back to help prevent Zika from spreading to others.
- Wear a hat, a long-sleeved shirt, long pants, shoes and socks. Treat clothes, shoes and other gear with a bug spray called permethrin, or wear permethrin-treated clothes if you’re spending time hiking, camping or doing other outdoor activities. Don’t spray permethrin directly on your skin. If you work outside, talk to your boss about getting bug spray or lotion to use at work, or ask if you can work inside. If you do have to work outside, make sure your clothes cover and protect your skin. The Occupational Safety and Health Administration has guidelines to help prevent you from being exposed to Zika at work.
- Stay in places that have air conditioning or screens on windows and doors to keep mosquitoes out. Make sure screens on doors and windows don’t have holes in them.
- Remove still water from inside and outside your home or workplace. Check things like flowerpots, buckets, animal water bowls and children’s pools. Scrub them clean and turn them over or cover them so that they don’t collect water. Mosquitoes can lay eggs inside or outside in very small amounts of water, like the size of a bottle cap. Use water treatment tabs that kill young mosquitoes in standing water. The tabs won’t harm you or your pets, but don’t use them in drinking water.
- If you’re in a Zika-affected area and sleeping outside or in a room that doesn’t have screens on doors and windows, sleep under a mosquito bed net. You can buy one at an outdoor store. Get one that’s approved by the World Health Organization Pesticide Evaluation Scheme (also called WHOPES) and that’s treated with permethrin. If you use a net with permethrin, don’t wash it or put it in the sun.
- Put mosquito netting across the top of your baby’s stroller or crib to help keep your baby safe from mosquitoes. Make sure it doesn’t touch your baby’s face or body.
How can Zika virus affect a baby during pregnancy?
Zika infection during pregnancy causes microcephaly and other serious brain problems. Microcephaly is when a baby’s head is smaller than expected, compared to babies of the same sex and age. Babies with microcephaly often have smaller brains that don’t develop properly. Not every baby whose mother has Zika is born with microcephaly. Researchers are working to find out how often Zika causes microcephaly when a baby is exposed in the womb.
Zika also may be linked to:
- Birth defects, including hearing loss and problems with the eyes. Birth defects are health conditions that are present at birth. Birth defects change the shape or function of one or more parts of the body. They can cause problems in overall health, in how the body develops or in how the body works.
- Growth problems in the womb
- Miscarriage. This is when a baby dies in the womb before 20 weeks of pregnancy.
- Stillbirth. This is when a baby dies in the womb after 20 weeks of pregnancy.
What are the signs and symptoms of Zika?
You can find out if you have Zika with a blood test or a urine test. Your health care provider may use both tests. Most people with Zika (about 80 percent or 4 in 5 people) don’t get sick and have no signs or symptoms. If you do get sick with Zika, it’s usually a mild illness, and you may not even know you’re infected.
If you do have signs or symptoms of Zika, they usually begin 2 to 7 days after you’ve been exposed to the virus. You can be sick with Zika for several days to a week. Signs and symptoms include:
- Fever (You may or may not have a fever if you have Zika.)
- Joint or muscle pain
- Pink eye (also called conjunctivitis) or pain behind the eyes
- Throwing up
There are no medicines to treat Zika. If you have signs or symptoms, you can:
- Get plenty of rest.
- Drink plenty of fluids.
- Take acetaminophen (Tylenol®) to relieve fever and pain.
If you or anyone in your family has or may have Zika, protect yourselves from mosquito bites. This can help prevent Zika virus from spreading to others.
If you or your partner have or may have Zika, when is it OK to get pregnant?
The CDC says:
- If you’ve been tested for and have Zika, wait at least 8 weeks from your first sign or symptom before trying to get pregnant.
- If your partner has been tested for and has Zika, wait at least 6 months after his first sign or symptom before trying to get pregnant.
- If you or your partner may have Zika but neither of you have signs or symptoms and neither of you has been tested, wait at least 8 weeks from when you think you may have been exposed to Zika before trying to get pregnant.
The CDC recommends that you wait this long to be sure you and your partner aren’t infected with Zika virus when you try to get pregnant. Zika infection usually stays in your blood for a few days to a week, but it has been found in an infected man’s semen more than 3 months after symptoms started.
Remember, most people who have Zika don’t have signs or symptoms. If you think you or your partner may have Zika but haven’t had signs or symptoms, talk to your provider.
If you’re pregnant, should you get tested for Zika?
The CDC doesn’t recommend Zika testing for all pregnant women. If you’re pregnant and may have been exposed to Zika virus, see your health care provider. Your provider may test your blood or urine. If you do have Zika, you may get more than one ultrasound throughout pregnancy to check your baby for signs of microcephaly or other health problems. Ultrasound is a prenatal test that uses sound waves and a computer screen to show a picture of your baby inside the womb. You also may get amniocentesis (also called amnio) to check for Zika virus in the amniotic fluid that surrounds your baby in the womb.
If you’re pregnant and live in a Zika-affected area or often travel to a Zika-affected area:
- If you have signs or symptoms of Zika, see your health care provider right away and get tested. If your test shows you have Zika or the test results are unclear, your provider may use ultrasound to check your baby for signs of microcephaly.
- If you don’t have signs or symptoms of Zika, your health care provider tests you for Zika in the first and second trimester as part of your regular prenatal care. Prenatal care is medical care you get during pregnancy. If you have Zika or the test results are unclear, your provider may use ultrasound to check your baby.
- If you have an ultrasound that shows that your baby has microcephaly or calcium deposits in the brain, you or your baby may be retested for Zika. Your provider also may want to test the placenta and umbilical cord for Zika after your baby’s birth.
If you’re pregnant and don’t live in a Zika-affected area but may have been exposed to Zika (through travel, unprotected sex with an infected man, a blood transfusion or exposure to infected body fluid or lab samples):
- If you have signs or symptoms of Zika within 2 weeks of your exposure to Zika, see your health care provider right away and get tested. If the test shows you have Zika or the test results are unclear, your provider may use ultrasound to check for signs of microcephaly.
- If you don’t have signs or symptoms, see your health care provider and get tested. If you get tested within 2 weeks of exposure and the tests are negative, see your provider for follow-up testing 2 to 12 weeks after your exposure to Zika. Even if you see your provider for the first time 2 to 12 weeks after exposure, get tested. If the test shows you have Zika or the test results are unclear, your provider may use ultrasound to check your baby.
- If you have an ultrasound that shows that your baby has microcephaly or calcium deposits in the brain, get retested for Zika. Your provider may want to test the placenta and umbilical cord for Zika virus after your baby’s birth.
If you think you’ve been exposed to Zika virus and don’t see your provider until 12 weeks or more after the exposure, it’s still important to tell your provider about it. She may test you for Zika or use repeat ultrasounds to check your baby for signs of microcephaly or other problems.
If you have Zika during pregnancy, your provider may want you to see a maternal-fetal medicine specialist or an infectious disease specialist. Maternal-fetal medicine specialists (also known as MFMs) are doctors with special education and training to take care of women who have high-risk pregnancies. An infectious disease specialist is a doctor with special training in the diagnosis and treatment of infections.
Your health care provider may talk to you about sharing information about your Zika infection with the CDC. The CDC has a registry to collect information about pregnant women and their children who have been infected with Zika. They use this information to learn more about the infection and its effect on pregnancy and babies.
What is Guillain-Barré syndrome? How is it related to Zika virus and how does it affect pregnancy?
In Brazil, there’s been an increase in the number of people with Zika who develop a rare disorder called Guillain-Barré syndrome (also called GBS). Researchers don’t fully understand what causes GBS, but some people get it after having the flu or other infections.
In a healthy person, the immune system protects the body from infection. If you have GBS, your immune system attacks your nerve cells. This can cause weak muscles and paralysis. Paralysis is when you can’t feel or move one or more parts of your body.
If you have GBS during pregnancy, you need treatment at a hospital so your provider can closely monitor your health and your baby’s health. GBS may increase your risk of pregnancy complications, including premature birth. This is birth that happens too early, before 37 weeks of pregnancy. Babies born this early can have serious health problems at birth and later in life.
If you think you have GBS, tell your provider. Signs and symptoms of GBS include:
- Breathing problems
- Fast heart rate
- Low or high blood pressure
- Muscle pain, aches or cramps, or muscle weakness in your arms and legs. You may have trouble walking or going up stairs.
- Tingling in your fingers, toes, ankles or wrists
- Problems with eye or facial movements. You may have trouble speaking, chewing or swallowing.
- Problems with your bladder or bowel. Your bladder is where your body holds urine. Your bowel is the tube that helps you digest food and carries solid waste out of the body.
Signs and symptoms of GBS usually last a few weeks. Most people with GBS get better, but some have lasting nerve damage.
If you’ve been exposed to Zika virus during pregnancy, does your baby need special medical care after birth?
If you’ve been exposed to Zika during pregnancy and your baby seems healthy at birth, you get tested for Zika. If you do have Zika or your Zika test results aren’t clear, your baby gets a physical exam and a blood or urine test to check for Zika virus and other health problems. She may get other tests, too, like testing of her spinal fluid. If your baby doesn’t have Zika, she just needs regular medical checkups unless she has signs and symptoms of other health problems.
If your baby has Zika or her Zika test results aren’t clear, her provider does these tests:
- A detailed physical exam to check her head size; her liver and spleen; and for rash or other skin damage
- Ultrasound to check her skull and brain
- Tests to check for problems with the nervous system. The nervous systems is made up of your brain, spinal cord and nerves. Your nervous system helps you move, think and feel.
- Hearing screening test. Even if your baby had a hearing test as part of newborn screening after birth, she should have another hearing screening when she’s 6 months old if she has or may have Zika.
- Eye exam, including an exam of the retina. The retina is the nerve tissue that lines the back of the eye.
Your baby’s provider closely monitors your baby’s growth and development during her first year. Some babies who have or may have Zika may need to see specialists, like a child ophthalmologist, for more tests. A child ophthalmologist is a doctor who treats eye and vision problems in children.
If you find out during pregnancy that your baby has microcephaly or your baby has microcephaly at birth, she’ll get a complete physical exam, tested for Zika and other medical care she needs.
If you had Zika during pregnancy or after giving birth, is it OK to breastfeed your baby?
Yes. Zika virus has been found in breast milk, but there are no reports of babies getting infected with Zika from breastfeeding.
Last reviewed: August 22, 2016