In January, a study was published. Nature MicrobiologyResearchers found a link among certain chemicals in cosmetics and hygiene products and an increased risk of preterm birth. These chemicals build up in the vagina, and are then broken down into substances that can affect fetal development.
While the gut microbiome gets a lot of attention for its role in health and disease, it’s not the only place bacteria like to call home. Your vaginal microbiome contains billions of microorganisms which, when healthy, can help protect your reproductive system.
Pregnancy puts additional pressure on the fragile balance of good and poor microbes within the vaginal microbiome. Preterm birth can be a risk factor for any changes that could lead to an unhealthy environment. A poor vaginal microbiome can lead to preterm birth and an unhealthy environment. Exposure to harmful toxins—some of which we can find right at home.
What causes preterm births?
Premature births account for 15 million babies every year. Preterm birth is not a common problem despite the high number. It appears that multiple factors are at work.
First there’s the genetic component. Scientists have identified six genes that are involved in the timing of a baby’s birth and the length of a pregnancy. Preterm births can also be inherited from families. 2020 research found that women who had three or more preterm babies were more likely to give birth early than women who have no such family history. Other research has suggested it’s the baby’s genes, not the mom’s, that causes preterm birth.
Many environmental factors can also increase the likelihood of preterm births. These are:
Some environmental factors can be avoided. Preterm births can be reduced by quitting smoking during pregnancy. The chemicals in personal care products were found to accumulate over time, according to the current study. This could be prevented by reducing the use of personal care products that contain known chemical toxins.
Related: 5 questions you should ask your first fertility appointment
Preterm births can be increased by chemical exposure to personal care products
The study authors took swabs from the vaginas 232 women during their second trimester. 80 preterm births were experienced by the 232 women.
Researchers focused their attention on the vaginal metabolome—a set of small molecules like metabolites produced by cells and bacteria living in the vaginal microenvironment.
“The metabolome can be seen as a functional readout of the ecosystem as a whole,” explains Tal Korem, PhD, an assistant professor in the program for mathematical genomics and the departments of systems biology and obstetrics and gynecology at Columbia University, in a press release. “Microbiome profiling can tell us who the microbes are; metabolomics gets us close to understanding what the microbes are doing.”
Related: Ara Katz wants children to love their microbiomes
The 232 pregnant women identified more than 700 different vaginal compounds. All women were able to identify 108 of the 700 metabolites, regardless of their delivery date. Researchers found that there were more metabolites in the 80 women who delivered earlier than the women who delivered to term.
Four metabolites were linked to spontaneous preterm delivery. Three of them—ethyl-beta glucoside, tartrate, diethanolamine (DEA)—were not created from existing vaginal microbes but from an outside source.
Although the source of this group of metabolites was not identified in the study, the researchers noted that many of them are found in cosmetics and hygiene products. These chemicals, despite being produced by outside sources, were found in more than 95% of preterm-born women.
Related: Male fertility may be affected by PFAS exposure
What does preterm birth look like?
The study authors suggest that choline could be a possible reason. Low levels of choline were associated with preterm births. This is an essential nutrient that aids in the growth and development the foetus. Preemies with low levels of choline in pregnancy are more likely to have short stature and premature organ development. Low levels of DEA metabolite have been previously shown to cause disruption in choline metabolism.
Related: More choline during pregnancy boosts kids’ attention
Metabolites could be a good biomarker for predicting preterm infant mortality
A team of machine learning algorithms was used to create an algorithm that could predict preterm births by measuring certain metabolites. Two groups of preterm or full-term women were tested to see if the model worked. The model was able to predict who would have preterm delivery in the middle or late stages of a pregnancy and it proved robustly accurate. The model was also found to be more accurate than models that only collect data on the vaginal microbiome or on the mother’s age, BMI and birth history.
The algorithm is an excellent starting point for preterm birth diagnosis. But don’t expect to find the tool in your doctor’s office anytime soon. This model was based only on the results of a small group of pregnancies. It’s also possible there’s another metabolite not seen in this group that could be linked to spontaneous preterm birth. Additionally, it’s hard to generalize the results against other groups of women in different stages of pregnancy.
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Your best option for now is to reduce your exposure to chemicals that can trigger early delivery. You might check to see if your products contain chemicals like DEA. Douching is a preterm birth-related product that you might want to avoid. If you’re unsure whether something you’re using could compromise your baby’s health, bring it to your next prenatal visit. They will be able to tell you if the products are safe or not.
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Fuchs F. Monet B. Ducruet N. Chaillet N. Audibert F. Preterm birth and maternal age: A large cohort study. PLoS One. 2018;13(1):e0191002. Published 2018 Jan 31. doi:10.1371/journal.pone.0191002
Kindschuh F, Baldini FF, Liu MC. Liao Y. Meydan Y., Lee HH. Heinken AB, Thiele I. Thaiss CA. Levy T. Preterm births are associated with xenobiotics. Nature Microbiology. 2023 Jan 12:1-4. doi:10.1038/s41564-022-01293-8
Koire A, Chu D, Aagaard K. Preterm birth is predicted by family history. Am J Obstet Gynecol MFM 2021;3:100277. doi:10.1016/j.ajogmf.2020.100277
Misra DP, Trabert B. African American women are at higher risk for preterm birth due to vaginal douching. Am J Obstet Gynecol. 2007;196(2):140.e1-140.e1408. doi:10.1016/j.ajog.2006.10.880
Soneji S, Beltrán-Sánchez H. Association of Maternal Cigarette Smoking and Smoking Cessation With Preterm Birth. JAMA Netw Open. 2019;2(4):e192514. doi:10.1001/jamanetworkopen.2019.2514
Zhang G, Feenstra J, Bacelis J. Liu X. Muglia LM. Juodakis J. Miller DE. Litterman N. Jiang PP. Russell L. Hinds DA. Genetic associations with gestational length and spontaneous preterm birth. New England Journal of Medicine. 2017 Sep 21;377(12):1156-67. doi:10.1056/NEJMoa1612665
