What pregnant women need to know about Zika in 2017

It’s summer in Texas, and the mosquitoes are back in full force. Well, they never really left this year. We didn’t get the cold weather this winter that normally helps control the mosquito population. That means this summer could be an especially buggy one.

Of course no one likes itchy mosquito bites, but for pregnant women they can be downright dangerous.

With mosquitoes and warm weather come rising risks of contracting the Zika virus, which exploded on the scene in 2015 and is still a serious health concern in parts of Texas. We may not yet understand the full effects of the virus, but it has been proven to cause serious birth defects.

Prevention is critical because Zika has no vaccine and no treatment. Going into summer 2017, here is what you need to know to guard you and your baby against the disease.

Zika in Texas

Three hundred twenty two people in Texas had symptoms of Zika infection from December 2015 to December 2016. Six of those people were likely infected by mosquitoes carrying the Zika virus in the lower Rio Grande Valley. The good news is that is the only part of Texas that has found Zika carrying mosquitos. The remaining cases were related to travel to areas with known cases of Zika transmission, such as Brazil, Mexico, or Puerto Rico. From January 1 through May 12 of this year the Texas Department of State Health Services reported an additional twelve cases.

Four out of five people who catch the Zika virus don’t get sick at all. But if a woman is infected with the virus – even if she has no symptoms – her unborn child is at serious risk for birth defects. The most recent estimates suggest there is a 10 percent risk of birth defects if a woman has Zika any time during her pregnancy – and it rises to 15 percent if the infection occurs in the first trimester.

Because of this, pregnant women are reported into a special U.S. Pregnancy Registry by the Centers for Disease Control and Prevention. Since Zika emerged as a concern at the end of 2015, the state of Texas has reported 192 pregnant women with any evidence of Zika infection to the registry.

State officials are particularly concerned about Zika transmission in south Texas. Brownsville, Texas (the Cameron County seat), remains a “yellow area,” where pregnant women are not recommended to visit and should consider postponing travel because risk of exposure to mosquitoes carrying the illness.

Texas Health and Human Services has expanded routine screening during pregnancy to six counties along the Rio Grande. Obstetricians in those areas are advised to check for evidence of infection in the first trimester and again in the second trimester. In the rest of the state, women are being screened only if they have a positive travel history or have symptoms following travel to or sex with a partner who traveled to a region with risk of Zika.

My concerns

I’m a little worried people aren’t taking this as seriously as they should.

One patient recently told me she went with her husband to Cancun early in her pregnancy. Another was planning a destination wedding in Puerto Rico. Fortunately, she and her doctor had a conversation about the need to avoid pregnancy for six months after returning. But did that message reach the members of her family and wedding party? There could be others in the group who were pregnant or were thinking about pregnancy in the next year and hadn’t really considered the ramifications of making the trip.

Patients aren’t the only ones who are a little confused. In early May, I attended a national meeting of Ob/Gyns and went to a seminar about late-breaking Zika updates. During a question and answer session, one physician asked about the safety for his patients to travel to Puerto Rico to get on a cruise ship for a trip around the Caribbean.

Puerto Rico is a definite “red area” and pregnant women should not travel there. All patients should review where the CDC has issued travel warnings before planning trips, especially if outside the United States.

Testing update

There are two different ways we test for Zika. In the first test, we look for the presence of the actual virus in a patient’s blood or urine.

This test has its limitations. While Zika doesn’t hang around long in blood or urine, the virus can hide in a man’s semen for a long time. That’s why the CDC recommends waiting six months after your partner has returned from an area with known Zika transmission to try to become pregnant or using condoms for the duration of pregnancy if your partner traveled to a country with a risk of Zika.

I’ve had lots of patients ask about Zika testing for their male partners who have traveled, in an effort to shorten condom use or reduce the wait time before attempting pregnancy. But commercial labs currently do not test semen, and receiving the “all clear” from a blood or urine test will not necessarily tell us whether the virus is present in semen.

The second type of test involves looking at whether your body has produced antibodies to Zika. This is how we check for immunity to rubella – we look for the presence of an IgG antibody which tells us a person has either had the illness or been vaccinated in the past.

IgM antibodies are a little different. If they show up in your blood, it means you’ve recently had that illness. Currently for Zika infection, we only have the IgM test. Until recently, we thought it would tell us that someone was infected two to 12 weeks before the blood test was performed. To make things more confusing, it now looks like the Zika IgM antibody might stay in the bloodstream longer, making it hard to pinpoint when the actual infection took place.

Our recommendations

• Don’t travel to an area with Zika (including U.S. cities like Miami or Brownsville) during pregnancy.
• If your partner needs to travel to any location with active Zika while you are pregnant, you need to use condoms for the duration of the pregnancy.
• Liberally use mosquito repellants and cover bare arms and legs as much as possible when outside.
• If you do travel, let your provider know. We are asking about travel to areas with Zika at every prenatal visit – don’t ignore this or let “no” become a rote answer.
• Finally, take a critical look around your yard for areas of standing water. The type of mosquitoes that transmit Zika typically don’t fly far and need very little moisture to lay eggs.

Other illnesses

Zika isn’t the only mosquito-borne illness for us to worry about this summer. Already around Dallas mosquitoes carrying West Nile Disease have been found. Fortunately, young, healthy pregnant women are less likely to suffer severe illness from an acute West Nile infection, and transmission to the fetus is very unusual.

For more information about pregnancy, labor, and delivery, sign up to receive Your Pregnancy Matters email alerts when we publish new stories. You can also make an appointment to see one of our specialists by calling 214-645-8300.