Infertility affects as many as one in five couples worldwide, or roughly 186 million people seeking pregnancy. Thorough medical checks often identify causes in the woman, man, or both partners, with some benefiting from treatment or assisted methods such as in vitro fertilization.

Yet many cases remain unexplained. Researchers at the Hebrew University of Jerusalem now propose that ongoing oral inflammation could contribute by sparking a body-wide immune reaction that reaches the ovaries. This process appears to cause oxidative stress, poorer egg quality, disrupted follicle growth, and fewer live births, offering a possible explanation for some idiopathic infertility.

Prof. Michael Klutstein of the Faculty of Dental Medicine, working with Prof. Asaf Wilensky and students Dr. Paz Kles and Stephen Ameho, led the work. Their study, published in the Journal of Dental Research, used a mouse model to examine how inflammation around dental implants spreads beyond the mouth.

In the experiments, female mice received titanium implants after molar extraction. Only one of four implanted females delivered a pup after mating, while all four untreated controls produced litters. The inflamed animals showed higher inflammatory cytokines in ovarian tissue, altered immune cell profiles, oxidative damage, impaired follicle development, and lower oocyte quality.

Klutstein noted that inflammation linked to endometriosis and lupus has long been studied, yet the mouth-to-ovary pathway had received little attention. The team was surprised by the strength of the connection. He suggested women planning fertility treatment first visit a dentist to rule out oral inflammation, and he called for closer cooperation between fertility specialists and dental professionals.

The oocytes also displayed DNA damage and epigenetic shifts resembling those seen in reproductive aging, hinting that inflammation may speed fertility decline. The findings add to evidence tying oral health to broader conditions such as heart disease, rheumatoid arthritis, type-2 diabetes, Alzheimer’s disease, chronic kidney disease, and inflammatory bowel disease.

Further human studies are needed, but the work points to potential anti-inflammatory or antioxidant interventions that could improve outcomes. The researchers did not examine miscarriage or pregnancy complications.