Zika virus and pregnancy

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.  

Download our Zika resources: 

• Zika and pregnancy fact sheet
• Zika and pregnancy infographic 

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 about a week after getting infected. 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 and birth. 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. 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.
• Through infected blood and body tissue, including semen. You may come in contact with infected blood or body tissue in a health care setting (like a laboratory) or if you have a blood transfusion. A blood transfusion is when you have new blood put into your body.

Where Zika is spreading?

The Centers for Disease Control and Prevention (also called the CDC) has maps that show where Zika is spreading around the world. These are called Zika-affected areas. You can see the maps at cdc.gov/zika. In 2018 and 2019, there have been no reports of mosquitoes spreading Zika in the continental U.S. 

If you’re pregnant or trying to get pregnant, don’t travel to a Zika-affected area unless you absolutely have to. If you do travel, talk to your provider before you go about how to protect yourself from Zika. This includes preventing mosquito bites and using a barrier method of birth control (like a condom or dental dam) if you have sex. Some barrier methods, like male or female condoms, keep a man’s sperm from reaching a woman’s egg, and some help protect against sexually transmitted infections (also called STIs, sexually transmitted diseases or STIs). A dental dam is a square piece of rubber that can help protect you from STIs during oral sex.  

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 yourself 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 go 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
• 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 Zika, wait to donate blood or umbilical cord blood. Wait at least 120 days after a positive Zika test or 120 days after you last had Zika symptoms, whichever time is longer, before donating. Umbilical cord blood (also called 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. Cord blood is collected when you give birth. To donate cord blood, your baby’s birth needs to be at least 120 days after a positive Zika test or you last had symptoms. If you have Zika and are thinking about donating or storing cord blood, talk to your provider.
• If you’re thinking about getting pregnant with donated sperm, talk to your provider. Donated sperm isn’t tested for Zika, but donors are asked if they’ve been in a Zika-affected area. If so, their sperm isn’t allowed to be used. But because the sperm’s not tested, there may be some risk of infection.

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, IR3535 and 2-undecanone. If the product contains DEET, make sure it has at least 20 percent DEET. Don’t put bug spray or lotion on your skin under clothes. If you use sunscreen, put it on before the spray or lotion. If you have children: 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 the spray or lotion on your baby’s hands or near her eyes or mouth. Don’t put the spray or lotion on cut, sore or sensitive skin.
• 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 severe 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:

• 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.
• Congenital Zika syndrome. This is a group of five health conditions present at birth that are linked to Zika infection during pregnancy. It includes birth defects (like microcephaly) and other health and development problems. Birth defects are health conditions that are present at birth. They change the shape or function of one or more parts of the body, and they can cause problems in overall health, in how the body develops or in how the body works. About 1 in 10 pregnant women (10 percent) with Zika infection in the United States and the District of Columbia has a baby with birth defects. Pregnant women with Zika infection during the first trimester may be more likely to have a baby with birth defects than women infected later in pregnancy.

If your baby is born with congenital Zika syndrome, he may need care from different providers. 

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. Signs of a condition are things someone else can see or know about you, like you have a rash or you’re coughing. Symptoms are things you feel yourself that others can’t see, like having a sore throat or feeling dizzy. You can be sick with Zika for several days to a week. The most common signs and symptoms of Zika are:

• Headache
• Fever (You may or may not have a fever if you have Zika.)
• Joint or muscle pain
• Pink eye (also called conjunctivitis)
• Rash

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 have signs or symptoms of Zika, wait at least 8 weeks from your first sign or symptom before trying to get pregnant. 
• If you think you were exposed to Zika but don’t have signs or symptoms, wait at least 8 weeks from when you think you were exposed before trying to get pregnant.
• If your partner has signs or symptoms of Zika, wait at least 3 months from his first sign or symptom before trying to get pregnant.
• If your partner has been exposed to Zika but doesn’t have signs or symptoms, wait at least 3 months from when he thinks he was exposed before trying to get pregnant.

The CDC recommends that you wait at least this long to be sure you and your partner aren’t infected with Zika virus when you try to get pregnant. If you live in or often travel to a Zika-affected area, talk to your health care provider about getting tested for Zika before you try to get pregnant. Zika infection usually stays in your blood for about a week, but it can stay in blood for more than 12 weeks.

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 before or during pregnancy, see your provider. Your provider may test your blood and urine for Zika. 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 a prenatal test called amniocentesis (also called amnio) to check for Zika virus in the amniotic fluid that surrounds your baby in the womb.

The CDC recommends you get tested for Zika during pregnancy if:

• You have signs or symptoms of Zika symptoms and you may have been exposed in the 8 weeks before you got pregnant or during pregnancy. You can get blood and urine tests for Zika up to 12 weeks after you first have signs or symptoms, but it’s best to get tested as soon as possible.
• You don’t have signs or symptoms of Zika, but you have an ongoing risk of being exposed to Zika (for example, you live in or often travel to a Zika-affected area or you have unprotected sex with an infected man). You get blood and urine tests for Zika at your first prenatal care checkup. If these tests are negative, you get tested for Zika two more times during pregnancy as part of regular prenatal care.
• You may have been exposed to Zika recently and ultrasounds show your baby may have signs of conditions that are part of congenital Zika syndrome. You get blood and urine tests for Zika. Your provider may want to test your baby’s placenta for Zika after birth. Testing can help your provider find out if your baby may have Zika-related birth defects.

If you may have been exposed to Zika recently, but you don’t have Zika symptoms and you don’t have ongoing exposure to Zika, talk to your provider about the risks and benefits of testing to decide if testing is right for you. If you have a miscarriage or stillbirth and you may have been exposed to Zika before or during pregnancy, your provider may recommend testing the placenta and other tissues for Zika.

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.

Depending on where you live, your state or local health department may have different testing recommendations than those from CDC. For example, recommendations for testing may be different from CDC’s because of the number or kind of mosquitoes in your area at certain times of the year. It’s OK for your health department to have its own recommendations based on the conditions in your area. For more information, contact your state, tribal, local or territorial health department.

If you have Zika during pregnancy, do you need special medical care?

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.

Are all babies tested for Zika infection after birth?

No. Your baby gets tested for Zika infection and health conditions that are part of congenital Zika syndrome if:

• Your baby has birth defects that are part of congenital Zika syndrome and you may have been exposed to Zika during pregnancy.
• Your baby doesn’t have birth defects that are part of congenital Zika syndrome, but lab tests show you possibly had Zika infection during pregnancy.

If you may have been exposed to Zika during pregnancy but you didn’t get tested or you got tested more than 12 weeks after your exposure, your baby’s provider may test him for Zika and check for signs of congenital Zika syndrome after birth.

If you have 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.

More information

• Zika virus and pregnancy fact sheet 
• Zika virus and pregnancy infographic
• Protect your baby from Zika factsheet
• Centers for Disease Control and Prevention (CDC)
• World Health Organization (WHO)

See also: Microcephaly

Last reviewed: May 2019