Plus, there are some other issues. Many aren’t regulated by the Food and Drug Administration. There is understandable confusion about which strains to use for certain health conditions. And speaking of strains, there are dozens of unpronounceable varieties on the market, each one promoting itself as a cure for a host of different problems. Of course, all of these already-muddy questions get even muddier when you apply them to pregnancy. Most studies of OTC drugs, vitamins, and supplements don’t include pregnant women, so any data we do have doesn’t usually apply to expectant people. Is this true for probiotics? Well…yes and no. Here’s what we know about the safety of taking probiotics during pregnancy.

What Are Probiotics, Exactly?

Probiotics are live microorganisms designed to enhance the bacterial “flora” of different parts of your body—primarily your gut, but also your mouth, urinary tract, and vaginal region. While some bacteria can make us sick, others are actually good for us and help keep us healthy. If we don’t have enough good bacteria, our body’s microbiome can get thrown out of balance, potentially leaving us vulnerable to illness or uncomfortable symptoms (like diarrhea).  That’s where probiotics come in: using microorganisms that are essentially the same as the ones naturally occurring in our bodies, probiotics can help us restore the balance of good and bad bacteria.  Some foods naturally contain probiotics, including yogurt and cottage cheese. There are also fermented products, such as sauerkraut, that offer probiotics. If you don’t like those foods or don’t usually have access to them, you can also take a supplement. Not everyone should or needs to take probiotics. Many of us have bodies that can regulate the balance of bacteria all on their own. But taking certain medications, like antibiotics, or having certain health conditions, such ad inflammatory bowel disease (IBD), can disrupt your microbiome more than usual.

Are Probiotics Safe to Take During Pregnancy?

We don’t have a definitive answer to whether probiotics are safe to use during pregnancy, explains Dr. Rose Chang-Jackson, OBGYN at Austin Regional Clinic in Austin, Texas. The data is limited for the general population, and a lot of what we have revolves around patient self-reports about symptom improvement. “There aren’t really any studies comparing head-to-head [the results] for patients who take them versus those who don’t,” she says. It’s important to note, though, that we also don’t have data signifying that probiotics are unsafe. “What we know by reviewing patient reports and looking at adverse events is that it seems fairly safe in pregnancy—there are no increased C-section rates or risks for preterm births,” Dr. Chang-Jackson says. For example, a 2018 review of studies published in “BMC Pregnancy and Childbirth” found that probiotic use during pregnancy neither reduced nor increased the risk of preterm birth—or any other maternal/fetal health outcomes, for that matter. 

Why Take Probiotics When Expecting?

While probiotics are often touted as miracle supplements for people with digestive disorders or chronic GI distress, Dr. Chang-Jackson says their most common use in pregnancy is actually for maintaining the vaginal flora, not for curing stomach ills. “Nausea and vomiting during pregnancy, as well as constipation, are due to hormonal changes," she explains. “So probiotics might not have as much of an effect [for pregnant women as they would for other people].” However, pregnant women are more susceptible to vaginal and yeast infections than non-pregnant women. Taking probiotics can help preserve the balance of the vaginal microbiome, may prevent the occurrence of infections, and can reduce the need for prescription medication to treat vaginal infections.  “Patients don’t usually know much about them, but we do tell ones with recurring vaginal infections that they can add probiotics to their routine,” Dr. Chang-Jackson adds.

Are There Risks or Concerns for Taking Probiotics When Pregnant?

Not especially, though again, we’re working off a lack of evidence all around. Still, the nature of probiotics makes them much less risky than many other OTC or prescription drugs. “Probiotics are generally considered safe to try [during pregnancy] since they’re processed through your gut,” the doctor says. “Plus, the bacteria we’re giving you are ones that are already colonized in your gut—basically, we’re giving you more of what you already have.” A 2011 study published in Canadian Family Physician confirms this theory, stating that whether taken orally or used vaginally, probiotics are safe, well-tolerated, and rarely have any systemic absorption that would make them unsafe during pregnancy and lactation.  There are a few words of warning, though, to anyone interested in taking probiotics (including pregnant women). Also, if you are taking certain medications—like antibiotics or antifungal medications—you should talk to your doctor about timing your use of probiotics so they don’t interfere with the effectiveness of your medication. 

Does It Matter What Type of Probiotics You Take?

Typically, the strains promoted for treating vaginal or yeast infections are from the lactobacillus family: lactobacillus acidophilus, lactobacillus rhamnosus, and lactobacillus reuteri.  Dr. Chang-Jackson says there is no specific strain she would recommend other than the ones commonly marketed to women needing vaginal flora support. She does, however, remind patients to be aware of the limitations of probiotics.  “Many of the probiotics that are sold aren’t cleared by the FDA, so just like with any supplement, you have to take it with a grain of salt,” she says.

How Often Should You Take Probiotics While Pregnant?

It will depend on the type of probiotic you purchase, since different brands may have different dosages and dosing instructions. Additionally, some probiotics are shelf-stable and some require refrigeration, so be sure you’ve read about the correct way to store your specific brand.  For the most part, says Dr. Chang-Jackson, as long as you’re following the package directions on whatever probiotics you purchased, they are generally safe to take during pregnancy.