What pregnant women actually need to know about herpes

When I saw the press release for a new study linking the risk of autism to maternal infection with genital herpes, my heart sunk. Because you can’t put two scary buzzwords like “autism” and “herpes” into a press release without creating this kind of media response:

Being a new mom can be frightening for anyone, and women with HSV-2—also known as genital herpes—tend to have it a lot worse than most. Lots of doctors are behind the times when it comes to sexually transmitted infections, and herpes in particular has a history of being incredibly stigmatized, even within the medical community—despite the fact that it’s by far the most common STI, and one that usually carries no symptoms at all.

So what’s the deal with this scary new study, and what do the 1 in 5 women of childbearing age who have herpes need to worry about?

Ladies with herpes: this new study isn’t about you

It’s not! Not even a little. The aforementioned and woefully misreported study published Wednesday in mSphere suggests that women who get HSV-2 during their pregnancy might have higher odds of delivering a baby who’ll be diagnosed with an autism spectrum disorder.

The jury is still out on what causes autism, but most researchers think the behavioral changes must be the result of some combination of genetic predisposition and environmental factors. One frequently proposed environmental factor is infection during pregnancy. In many mouse studies and several human epidemiology studies—projects where researchers went back to look at available medical data for autistic children and their mothers to try to find some kind of pattern—scientists have found a link between infections during early and mid-pregnancy and neurological problems like autism and schizophrenia.

This new study didn’t uncover anything groundbreaking: Just like many studies before it, it showed a correlation between infection during pregnancy and rates of autism diagnosis. Infection during pregnancy is the key point here: the herpes itself had nothing to do with it. Women who’d carried the chronic STI in their nerve cells for some time before pregnancy showed no increase risk for their children. Whatever is happening here, it’s the body’s immune response that’s important—not the virus itself. This one study found that HSV-2 seemed to raise risk even when other infections they examined did not, but another paper found that any diagnosis of an infection at all during pregnancy raised the risk of an autism diagnosis by nearly 1/3. So it remains to be seen whether a mother’s immune response to herpes really is more dangerous than her response to the flu, for example. And it’s unlikely that an infection of any kind can be blamed solely for a baby’s autism—it’s likely just one piece of a genetic and environmental puzzle that scientists are only just beginning to put together.

While it’s tempting to make it sound like herpes is the star of the new study, that’s really nothing more than a cheap shot—an attempt to turn STI stigma into salivating clickbait. And in any case (one more time for the people in the back) the risky thing is to get herpes while pregnant, not to have it when you get pregnant.

In fact, prospective moms should not be afraid of their herpes at all

You may have heard that the risk of herpes transmission from mother to newborn—which can be fatal for the infant—means that HSV-positive moms need to opt for c-sections. But in many cases, this simply isn’t true. Once again, it’s herpes acquisition during pregnancy that should cause concern. In fact, it’s sort of the reverse risk scenario of that described in the new study: Moms who get herpes in the first or second trimester are likely to develop antibodies to the virus in time to pass them along to their fetus—something that a mom who had herpes before getting pregnant will do regardless of how long she’s has the virus, or how many symptoms she may or may not have. It’s only a late-in-pregnancy infection that poses a big risk, since the baby might be exposed to the virus during birth without having received a nice big boost of antibodies beforehand.

According to the Centers for Disease Control and Prevention, the risk of transmission from a mother with a history of herpes (or who acquired it early during the pregnancy) to her neonate is less than one percent. The risk can raise as high as 50 percent, but only as the primary infection gets very close to the delivery itself. It’s true that doctors might advise these mothers, or anyone with a visible outbreak of herpetic blisters when they go into labor, to choose a c-section over a vaginal delivery. But most HSV-positive moms can give birth however they’d like.

You know what we need? More testing!

The best way to protect your unborn child from any possible HSV-related risks is to know your STI status when you get pregnant—and make sure any partners you plan on continuing to have sex with during the pregnancy do the same. Studies have shown that most people who have herpes have no idea they’ve got it—and most people with the STI never experience symptoms—so making your partner or partners get tested is crucial. Your partner may be quite certain that they’ve never had itchy blisters on their genitals, but that doesn’t mean they don’t have HSV-2—which they’re perfectly capable of passing on to you, blisters or no. It might sound funny to demand a full STI screening panel at your first ultrasound appointment, especially if you’re in a committed monogamous relationship with the co-parent of your unborn child. But if either of you is unsure of your status, that’s the time you want to find out.

Knowledge is power, and it is possible for someone with HSV-2 to keep their partner from getting it. Condoms cut risk in half, and so (according to some research) does the use of suppressive anti-viral therapy. If you’ve already got herpes, there’s nothing to worry about—you and your doctor can monitor your symptoms and come up with the birth plan that makes the most sense.