What to expect (from your vaginal microbiome) when you’re expecting

There’s one gift your mother has given you that may stay with you your whole life: the millions of microorganisms she passed to you during birth and through her breastmilk, your microbiome. While your own unique microbiome begins developing during your first year, this inherited microbiome plays a huge role in protecting you from disease during this vital period.

But what about the other side of coin? A pregnant mother’s vaginal microbiome doesn’t just affect her unborn child—it also affects her own health. Research has found that the vaginal microbiome changes during pregnancy and the postpartum period. These changes can have a huge effect on pregnancy outcomes, with some kinds of bacteria leading to increased risk of preterm delivery.

While the research on the vaginal microbiome during pregnancy is still developing, here’s a summary of what researchers do know. By learning more, you can take steps to help encourage a healthy vaginal microbiome during pregnancy and beyond.

Your vaginal microbiome changes during pregnancy

Several studies have revealed that vaginal microbiome changes during pregnancy. Generally, pregnant women’s microbiomes have lower rates of bacterial diversity (meaning a lower number of species in the environment) as compared to those of non-pregnant women.

Pregnant women also tend to have larger populations of Lactobacillus, a “good” bacterium which is key to a healthy vaginal microbiome. This abundance of Lactobacillus may be caused by an increase in vaginal mucus in pregnant women, which leads to more glycogen, a carbohydrate Lactobacillus lives on. Pregnant women also tend to have smaller populations of Ureaplasma, a bacterium found in the urinary tract that can cause vaginal infections.

Everyone’s vaginal microbiome is different, including during pregnancy. While researchers can’t predict the exact makeup of a pregnant woman’s microbiome, the vaginal microbiome does generally correlate with several factors. For example, there are differences in vaginal microbiome correlated with ethnicity, with white and Asian American women having higher concentrations of Lactobacillus and black and Latina women having more diverse vaginal ecosystems. Everyone’s vaginal microbiome is unique, so researchers advise that it’s better to know your own unique vaginal microbiome before pregnancy so you can track how it changes.

Your vaginal microbiome doesn’t just change when you’re expecting. It undergoes a sharp change after delivery, too. Postpartum, most women’s vaginal microbiomes change to include lower concentrations of Lactobacillus and more bacterial diversity. While researchers have yet to discover the health impacts of your changing postpartum microbiome, it could have an effect on maternal health, especially for women who choose to get pregnant again soon after delivery.

An unbalanced vaginal microbiome can contribute to pregnancy risks

As we mentioned above, friendly Lactobacillus bacteria tends to proliferate during pregnancy, but that’s not true for every woman. Bacterial imbalances can take hold while you’re expecting, too.

This is important, because several studies have shown that low populations of Lactobacillus and high levels of Gardnerella are correlated with premature delivery. In fact, undetected amniotic fluid infection is one of the most common causes of preterm births—and researchers think that these infections could come from the pregnant woman’s own microbiome.

Bacterial vaginosis (BV) is a very common vaginal condition characterized by a relatively low abundance of Lactobacillus and an overgrowth of other kinds of bacteria, like Gardnerella vaginalis, Prevotella spp, and more. BV is also associated with preterm birth. Though exact results can vary from woman to woman, in general, a lower level of Lactobacillus and a higher level of other bacteria like Gardnerella or Ureaplasma can be linked to an increased risk of preterm birth.

Here’s how to promote a healthy vaginal microbiome when you’re expecting

Researchers are still investigating the links between specific species of bacteria in the vaginal microbiome and pregnancy complications. However, numerous studies suggest that knowing the composition of your vaginal microbiome can help keep you stay healthy—and protect the health of your child.

Screening tests like uBiome’s SmartJane can tell you not only the composition of your very own vaginal microbiome, they can also test for problems like BV, which may be symptomless but can increase your preterm delivery risk.

You can help keep yourself and your child healthy by making vaginal health part of your prenatal health routine. Eating good foods, staying away from toxins, and making sure you get all your recommended nutrients is good for you, and for the bacteria that keep your vagina healthy and happy. Your vaginal microbiome is a gift you’ll give your child for life—so why not take care of it now?

Talk to your healthcare provider about how your vaginal microbiome may affect your pregnancy. uBiome’s SmartJane test can help monitor your vaginal microbiome before and during pregnancy, including screening for potentially harmful conditions like bacterial vaginosis.