An Unknown Cause of Infertility

Although the construct of the family unit is evolving, having children remains important to the majority of adults. Yet, more and more adults are experiencing difficulties having children and are turning to assisted reproductive methods to start a family. A reported 10% of the population are infertile, although from personal experience, I believe that number is much higher. This is due to a multitude of reasons, one of the reasons being advanced maternal age. The CDC reported that the average age of women giving birth to their first child rose to 27.3 years of age, and delayed childbearing, having your first baby over 35, has rose 9 fold since women and men are focusing on creating successful careers and enjoying life before buckling down to raise a family. Over 50% of people with advanced educational degrees have been exposed to reproductive medicine. But, when they do decide to begin trying for a family, seemingly healthy adults are struggling to conceive. What was once thought to be a woman’s issue, 50% of the infertility cases is due to the male partner. Besides advanced age, what else could be contributing to infertility in healthy adults?

One part of the body that few are looking to for the cause is their mouth. I know this because I have been a patient of several fertility clinics and not one clinic asked about my oral health, yet the research is clear that oral health is vital to fertility. It is known that bacteria from the mouth, mainly Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn) leave the mouth, penetrate the gum tissues, enter the blood stream, and damage the reproductive system in a number of ways. See, our gingival tissues are meant to be a protective barrier to keep what is in the mouth out of the body, but when harmful bacteria and inflammation are present, the gingival tissues break down, become leaky (like leaky gut!) and allow what is in the mouth to penetrate the body. An infection with Fn alone will increase infertility by three times!

Let’s start with the males since infertility has historically thought to be a woman’s problem. In males, a properly functioning penis is important for conception, but men can develop erectile dysfunction from periodontal disease. A Pg infection will decrease arginine in men and arginine is a precursor for nitric oxide which is responsible for ‘raising the flag.’ Bacteria in the sperm (bacteriospermia) also reduces sperm count and their motility. Obviously, you need a high number of sperm and strong motility to fertilize the egg. If any one of these crucial steps is harmed, conception becomes very difficult.

In women, the effect of bacteria is outstanding. There are many ways in which gum infection (yes gingivitis is included here) makes it difficult for a woman to conceive. Fn is widely known to cross the placenta causing pregnancy developmental issues and Pg creates issues trying to conceive. Having chronic inflammation in the mouth alone is linked to endometriosis and pelvic inflammatory disease which are known causes of infertility because they can inhibit ovulation. If you don’t have an egg, there is zero chance of pregnancy! Fn and Pg can damage and/or prevent ovulation from occurring or the embryo from implanting in the uterus. Even if the woman does conceive, she is not out of the woods as 40% of all pregnant women have some form of gum infection during pregnancy. This is due to oral hygiene habits while not feeling their best and the increase in pregnancy hormones. Fn during pregnancy loves the uterus and easily colonizes there. Fn causes an increased risk for preterm births and low birth weight babies by rupturing the amniotic membranes which can be detrimental to their ability to thrive. In the worst of cases, Fn can lead to still births.

The reason why it is so crucial for women and men undergoing fertility treatments to seek dental care is because periodontal disease also decreases the success rate of infertility treatments. The medications and hormones used in infertility treatments increase inflammation, exacerbating the leaky gum issue and bacteremia. If you already have a bacterial infection in the mouth, and then you begin taking medications that increase inflammation and leakiness of the gingival tissues, the result is more bacteria into the blood stream and to the reproductive center. Periodontal disease causes bacteremia, endotoxemia, cytokine production and increased immunity to heat shock proteins, all of which have been associated with reproductive failure.

All of this is to say that if you are thinking about conceiving, are trying to conceive, or are undergoing expensive infertility treatments, ensure your mouth is healthy to improve your chances of having a baby. There are so many factors that go into creating a miracle and the health of your mouth is one that you can control, so why not check it?


  4. Shahryar K. Kavoussi et al., “Periodontal Disease and Endometriosis: Analysis of the National Health and Nutrition Examination Survey,” Fertility and Sterility 91, no. 2 (February 2009): 335–342,; Allison McKinnon et al., “A Case of Adolescent Pelvic Inflammatory Disease Caused by a Rare Bacterium: Fusobacterium nucleatum,” Journal of Pediatric & Adolescent Gynecology 26, no. 6 (December 2013): e113–e115,
  5. Susanna Paju et al., “Porphyromonas gingivalis May Interfere with Conception in Women,” Journal of Oral Microbiology 9, no. 1 (2017),
  6. Haytaç, Cetin, and Seydaoglu, “The Effects of Ovulation Induction.”
  7. Cenk Haytaç, Turan Cetin, and Gulash Seydaoglu, “The Effects of Ovulation Induction during Infertility Treatment on Gingival Inflammation,” Journal of Periodontology 75, no. 6 (June 2004): 805–810,
  8. Emily Brockette, “Infertility and Inflammation: The Potential Connection to Periodontal Disease,” Dentistry IQ, May 21, 2018,
  9. Piaopiao Chen, Feiruo Hong, and Xuefen Yu, “Prevalence of Periodontal Disease in Pregnancy: A Systematic Review and Meta-Analysis,” Journal of Dentistry 125, (October 2022): 104253,
  10. Marjorie K. Jeffcoat et al., “Periodontal Infection and Preterm Birth: Results of a Prospective Study,” Journal of the American Dental Association 132, no. 7 (July 2001): 875–880,; “Dental Care and Pregnancy” WebMD, March 4, 2022,’t%20let%20the%20word,who%20also%20have%20pregnancy%20gingivitis.

Katie Lee DDS