Maternal periodontitis may cause lower birth weight in children: genetic evidence from a comprehensive Mendelian randomization study on periodontitis and pregnancy

Abstract

Objectives This study aims to comprehensively investigate the potential genetic link between periodontitis and adverse pregnancy outcomes using a two-sample Mendelian Randomization approach. Materials and methods We employed robust genetic instruments for chronic periodontitis as exposure data from the FinnGen database. Data encompassing various pregnancy stage outcomes, including pre-pregnancy conditions (irregular menstruation, endometriosis, abnormal reproductive bleeding, and female infertility), pregnancy complications (hemorrhage, spontaneous miscarriage, and abnormalities in products), and post-pregnancy factors (single spontaneous delivery, labor duration, and birth weight of the child), were obtained from the UK Biobank. The random-effects inverse-variance weighted (IVW) method was utilized to compute primary estimates while diligently assessing potential directional pleiotropy and heterogeneity. Results Our findings indicate a negative association between periodontitis and labor duration (odds ratio [OR] = 0.999; 95% confidence interval [CI]: 0.999 to 1.000; P = 0.017). Individuals with periodontitis are more likely to deliver lower-weight infants (OR = 0.983; 95% CI: 0.972 to 0.995; P = 0.005). We found no evidence of pleiotropy or heterogeneity in aforementioned two associations. We did not observe casual links with pre-pregnancy conditions and pregnancy complications. Conclusions This Mendelian Randomization study underscores the genetic influence of periodontitis on specific adverse pregnancy outcomes, particularly concerning labor duration and lower birth weight deliveries. Clinical relevance Our study emphasizes the critical importance of maintaining periodontal health during pregnancy and offers genetic evidence supporting these associations. Further investigation is required to delve deeper into the specific underlying mechanisms.