Of four female mice fitted with dental implants, one gave birth. It produced a single live pup. All four untreated mice in the control group delivered litters within five weeks of mating.
That contrast is the core result of a Hebrew University of Jerusalem study suggesting that chronic inflammation in the mouth can impair female fertility. It was published in the Journal of Dental Research under the title “Chronic Oral Inflammation Impairs Female Reproduction in a Murine Model.”
How the experiment worked
Prof. Michael Klutstein of HUJI’s Faculty of Dental Medicine, who heads the Chromatin and Aging Research Lab, led the work with Prof. Asaf Wilensky, head of periodontology at Hadassah Medical Center-Hebrew University, and students Dr. Paz Kles and Stephen Ameho.
Every female mouse had her upper left molars extracted under full anesthesia and pain relief. After four weeks of healing, two titanium implants were placed in the implanted group, while the controls got none. The females were mated four weeks after implant placement; the males had no procedures and served only as mates. Tissues were collected after the mice were euthanized.
The team chose dental implants because inflammation around them is a common clinical scenario, and then followed how immune signals travelled through the body.
What they found
The inflammation did not stay in the mouth. It set off a systemic immune response that reached the ovaries, where cytokine levels rose and immune cell populations shifted. Ovarian tissue showed oxidative damage, follicles developed poorly, and egg quality dropped. Live birth rates fell sharply.
Oocytes also showed DNA damage and epigenetic changes like those seen in reproductive aging. That points to a possible way inflammation could speed the decline in fertility.
“Inflammation is often thought of as a localized response, but our findings show that it can have systemic consequences that extend as far as the reproductive system,” Klutstein said. He added that the work suggests chronic oral inflammation “may be an underrecognized factor in female infertility.”
The unexplained third
Infertility affects up to one in five couples, or 186 million people worldwide. Klutstein told The Jerusalem Post that when couples cannot conceive, a third of cases involve the woman, a third involve her partner, and the remainder are unexplained. “Our discovery could help find the reason for this third group,” he said.
Men’s fertility might suffer similarly, he said, but there is a difference: women have a limited number of ova, while men have huge numbers of sperm.
His group has studied chronic inflammation and fertility for 11 years, including diseases such as endometriosis and lupus. The open question was whether inflammation could travel from the mouth to the ovaries. Klutstein said he did not expect the evidence to be so strong, and that the team was among the first in the world to look at it.
Limits and next steps
The work was done in mice, and human studies are still needed. The study did not examine whether oral inflammation might cause miscarriage or pregnancy complications. Even so, Klutstein said women planning fertility treatment would do well to see a dentist first to check for oral inflammation. “Fertility specialists and dentists should cooperate more,” he said. His team is looking for a drug that women could take before treatment.
Chronic oral inflammatory conditions such as periodontitis are widespread and have already been associated with heart disease, rheumatoid arthritis, type-2 diabetes, Alzheimer’s disease, chronic kidney disease and inflammatory bowel disease. The US Centers for Disease Control and Prevention reports that 47.2% of American adults aged 30 and older have some form of periodontal disease.
Consult your doctor for medical advice.
