This mosquito-borne illness can threaten your unborn baby’s health. Here’s what you need to know about the Zika virus.

If you’re pregnant – or trying to conceive – the Zika virus is probably a top-of-mind concern right now, and with good reason: this mosquito-borne virus is dominating headlines with its scary multi-country advance and potentially devastating consequences for pregnant women and their babies.

Zika surfaced last May in South America, and Brazil has been disproportionately affected, with thousands of babies suffering severe birth defects, including brain damage, in utero when their mothers contracted the virus. But it has now spread to nearly three dozen countries, and has even shown up in the United States (although it’s important to note that the U.S. cases were brought by returning travelers from affected regions). The virus is likely to spread further, according to the World Health Organization (WHO), because the mosquito that transmits Zika is in all but two countries of the Americas, and the people in these regions lack immunity to the virus.

If you’re expecting (and frankly, even if you’re not), it’s crucial to arm yourself with information and up-to-date advice. This is what you need to know:

What is Zika virus?
The Zika virus is an insect-borne illness that can be primarily transmitted by infected Aedes mosquitoes, the same kind that carries dengue and yellow fever. The name comes from the Zika Forest in Uganda where monkeys with the virus were first found in 1947.

Why is it dangerous?
For the relatively few people who show signs of a Zika infection, the illness is often very mild. But in pregnant woman, the effects can be devastating, and can include pregnancy loss or a baby born with an abnormally small head and brain- a condition known as microcephaly. Microcephaly may be associated with developmental delays, mental retardation, and seizures, and in some cases can be fatal.

Because the Zika virus has been associated with significant risk to the fetus, the assumption is that the effects seen are in fact caused by the virus. But there are still many unknowns -including how likely it is that an infection in a pregnant woman will be passed on to her fetus; whether some fetuses are infected but don’t develop microcephaly; how often pregnancy loss may occur in expecting women with Zika virus; and whether pregnancy makes women more susceptible to the virus.

While the Zika virus remains in the blood of an infected person for a few days to a week, according to the CDC, there’s no current evidence to suggest that it poses a risk of birth defects in future pregnancies. And Zika won’t cause infections in a baby that’s conceived after the virus has left the bloodstream.

How is Zika transmitted?
In a scary new update, the CDC confirmed in early February the first U.S. case of Zika virus infection that is believed to have been transmitted sexually, from a traveler to a non-traveler in the United States. But Zika is primarily spread through the bite of infected mosquitos. When a mosquito bites and draws blood from someone who’s infected, the insect itself becomes infected and then goes on to bite other people.

The Zika virus can also be transmitted from mother to baby during pregnancy or around the time of birth, but according to the American College of Obstetricians and Gynecologists (ACOG), there are no clinical studies to measure the risk to an unborn child if the mother is infected.

Zika virus has been detected in fetal tissue, amniotic fluid, full-term infants, and in the placenta, according to ACOG, and trace amounts of the virus have also been found in breast milk, but because the amount is tiny, it’s unlikely to pose a threat. Oral infections of Zika haven’t been documented and, if one were to occur, it would likely be the same mild version as seen in adults. The many benefits of breastfeeding outweigh this possible risk.

What are the symptoms of Zika?
A Zika infection is similar to a mild case of the flu and may include such symptoms as a low-grade fever, headache, rash, muscle and joint pain, and conjunctivitis (pink eye). Symptoms may last several days to a week. Only 20 percent of people infected with the Zika virus will actually become ill. We don’t know at this time if pregnant women are more likely to develop symptoms if infected.

Testing for Zika virus
Right now there’s no commercially available test for Zika virus; just a few state health departments are able to test for it, and the test isn’t perfect. Because it cross reacts with other related viruses, it’s possible to have a positive test but not actually have the Zika virus. Because of this, the CDC recommends the test only for people who’ve been exposed (i.e., traveled to a high-risk country) and show symptoms.

Federal health officials are urging that newborns be tested if the mother has visited an affected area and also exhibits symptoms of the Zika virus. Your healthcare provider should contact the health department for information about testing for Zika. Even if you don’t show signs, your unborn baby should be examined, usually via ultrasound. If there are concerns following an ultrasound, amniocentesis may be the next step.

Reducing the risk
Because there’s no vaccine for Zika, the best way to reduce your risk is to stay current with the latest recommendations. If you’re pregnant, delay travel to the regions listed in the CDC’s advisory. If travel can’t be avoided, take every precaution to avoid mosquito bites, including:
• Wearing shirts with long sleeves and pants, rather than shorts
• Using bug spray with DEET, which is safe for pregnant and nursing women (check the label and follow the directions carefully)
• Treating clothes with permethrin, a type of insecticide
Additionally, the CDC recommends avoiding exposure to semen from someone who has been exposed to Zika virus; and if you’re trying to conceive, talk to your healthcare provider if your partner has been exposed to Zika virus.

The latest recommendations
The CDC has issued a level-2 travel notice urging women who are pregnant to avoid visiting the following countries: American Samoa, Barbados, Bolivia, Brazil, Cape Verde, Colombia, Commonwealth of Puerto Rico- US Territory, Costa Rica, Curacao, Dominican Republic, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Jamaica, Martinique, Mexico, Nicaragua, Panama, Paraguay, Saint Martin, Samoa, Suriname, Tonga, U.S. Virgin Islands, and Venezuela.

This list is changing almost daily, so it’s important to check the CDC’s travel information site for updates.
Pregnant women in any trimester – as well as women who are trying to become pregnant or thinking about becoming pregnant – should talk to their doctor or other healthcare provider before traveling to these areas and strictly follow steps to avoid mosquito bites during the trip. Although most viruses have a more serious impact during the first trimester, we can’t say whether this is completely true for Zika.

As always, contact your healthcare provider for specific questions or concerns you may have.

– Leslie