Self-reported periodontitis and fecundability in a population of pregnancy planners
Authors: Bond J C , Wise L A , Willis S K , Yland J J , Hatch E E , Rothman K J , Heaton B 
Published: February 2021

Abstract

STUDY QUESTION
Is a history of periodontitis among women associated with reduced fecundability?

SUMMARY ANSWER
A history of periodontitis, as assessed by three different self-reported measures, may be associated with reduced fecundability.

WHAT IS KNOWN ALREADY
Periodontitis is a chronic inflammatory condition affecting the hard and soft tissues surrounding the teeth. Few studies have evaluated the association between periodontitis and time to pregnancy, and findings are mixed. It is hypothesized that periodontitis may adversely affect time to pregnancy.

STUDY DESIGN, SIZE, DURATION
We conducted a prospective cohort study of 2764 female pregnancy planners residing in North America (March 2015–June 2020).

PARTICIPANTS/MATERIALS, SETTING, METHODS
Eligible participants had been attempting pregnancy for six or fewer menstrual cycles at enrollment and were not using fertility treatment. Women answered questions about their oral health. Pregnancy was ascertained via bi-monthly follow-up questionnaires. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs) for three different measures indicative of a history of periodontitis: ever diagnosed with periodontitis (N = 265), ever received treatment for periodontitis (N = 299), and ever had an adult tooth become loose on its own (N = 83). We adjusted for potential confounders and precision variables. Women at risk of misclassification of periodontitis diagnosis due to pregnancy-related gingivitis were reclassified in a sensitivity analysis.

MAIN RESULTS AND THE ROLE OF CHANCE
All three indices of periodontitis may be associated with reduced fecundability. FRs were 0.89 (95% CI 0.75–1.06) comparing women with and without a previous periodontitis diagnosis, 0.79 (95% CI 0.67–0.94) comparing women with and without previous periodontitis treatment, and 0.71 (95% CI 0.44–1.16) comparing women with and without a tooth that became loose. After reclassification of pregnancy-related gingivitis in the sensitivity analysis, the FR for periodontitis diagnosis was 0.83 (95% CI 0.68–1.00). Weaker FRs were observed among parous women as compared with nulliparous women for periodontitis diagnosis and tooth becoming loose, but not for periodontitis treatment.

LIMITATIONS, REASONS FOR CAUTION
Though we used validated self-report measures of periodontitis, clinical confirmation is the gold standard. These questions may be functioning as markers of different levels of periodontitis severity, but we were unable to measure disease severity in this population. Finally, we cannot eliminate the possibility of unmeasured confounding.

WIDER IMPLICATIONS OF THE FINDINGS
This is the first preconception prospective cohort study to evaluate the association between self-reported periodontitis and fecundability. Our results indicate that periodontitis may be associated with lower fecundability.

STUDY FUNDING/COMPETING INTEREST(S)
This work was partially funded by R01HD086742/Eunice Kennedy Shriver National Institute of Child Health and Human Development and R21HD072326/Eunice Kennedy Shriver National Institute of Child Health and Human Development. PRESTO has received in-kind donations from Swiss Precision Diagnostics, Sandstone Diagnostics, FertilityFriend.com, and Kindara.com for primary data collection. L.A.W. is a fibroid consultant for AbbVie, Inc. J.C.B., S.W., J.Y., K.J.R., E.E.H., and B.H. have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER
N/A.