It has been a year since scientists officially confirmed that Zika, a mosquito-borne virus that can also be spread through unprotected sex, can cause serious birth defects.

While scientists are still trying to answer a host of questions about this strange and troubling disease, they've learned enough to know what precautions new and expecting parents should take. 

Some of those precautions (like wearing an EPA-approved insect repellent and avoiding travel to Zika-affected regions) have been in place since the outbreak began. But others, such as when and how often to get tested for Zika, have recently evolved. 

Here's a breakdown of the Centers for Disease Control and Prevention's recommendations for how to protect yourself from Zika if you are pregnant or are thinking of having a baby:

Know the Risks

An infected mother can pass the virus on to her developing fetus at any point during her pregnancy, but the risk of that fetus developing severe birth defects as a result is greatest during the first trimester. 

An infected fetus has about a 3 to 4 percent chance of developing microcephaly—a condition marked by a severely underdeveloped brain and an abnormally small head, and the most severe Zika-related birth defect reported to date. 

For other, less severe birth defects, including hearing loss, vision trouble, and cognitive deficits, the numbers are fuzzier. In one recent analysis of Brazilian cases, 42 percent of babies exposed to the virus went on to develop these other problems. But according to data from the U.S. Zika Pregnancy Registry, the rates here were much lower. Just 5 percent of babies born to mothers with suspected Zika virus infection developed birth defects other than microcephaly, and just 10 percent of babies born to women with confirmed infections did.   

Get Tested

Before you conceive: If there's a chance you were exposed to Zika, ask your doctor for a Zika antibody test before you become pregnant. Because the test can detect antibodies months after the infection passes out of your system, it can be difficult to tell whether a positive test during pregnancy signifies a risk to your fetus. (The antibodies may linger after the infection passes, but the virus can be passed to your fetus only if it's in your system while you're pregnant). 

During your pregnancy: If you've traveled to (or live in) a Zika-affected region, you should be tested for Zika early in your pregnancy, then at least once every trimester. And if you undergo amniocentesis, a test sometimes done during pregnancy to check for genetic and other health problems, ask your doctor to test for Zika then, too.  

After your baby is born: If you tested positive for the virus during your pregnancy, or if you developed flulike symptoms after returning from a Zika-affected region, your baby should have a Zika test at birth. The infant should also have a head ultrasound or CT scan within the first year of life, and routine hearing, vision, and cognitive tests to check for brain defects that might not be evident at birth. The CDC recently reported that at least one-third of doctors and families skipped these tests. 

Protect Yourself and Your Baby

Before you conceive: If there's a chance that you or your partner has been exposed to Zika, you may want to delay pregnancy for at least six months. That's how long the virus can stay in the genital tract, and thus how long it can potentially infect a developing fetus.  

More on Pregnancy and Childbirth

During your pregnancy: Protecting yourself from Zika during pregnancy is the same as protecting yourself at other times but more urgent, because if the virus gets into your bloodstream, it can cross the placenta and attack your baby's developing brain.

You should avoid travel to affected regions. And if your partner has traveled to an affected region, he or she should wear insect repellent for at least two weeks after returning because that's how long the virus remains in the bloodstream (where it can be passed to another mosquito and from there to another human). Abstain from unprotected sex with anyone who may have been exposed to the virus. 

Finally, wear an effective insect repellent on your exposed skin, and on your clothing if you're going to be outside for long periods of time.

After your baby is born: The virus is most damaging to the brain when neurons are still developing, which is why Zika usually causes no symptoms in adults but can wreak havoc on a fetus. But because brain development continues after birth, scientists and parents alike have worried whether babies bitten by Zika-carrying mosquitoes also faced an increased risk of neurologic damage. So far there's no evidence of that. Still, if you live in an area where Zika is spreading (see the tool below), it's wise to protect babies from mosquito bites by making sure windows have screens or, if necessary, using a mosquito net. And when outdoors, make sure you use an effective repellent.

Guide to Mosquito and Tick Diseases

Where Most Cases Occur

Serious Side Effects

Symptoms appear


Common Symptoms