Global Oral Health Birth Cohort Studies: A Living Scoping Review

In 2020, a scoping review mapped the existing Oral Health Birth Cohort Studies (OHBCS). Given the rapid growth and disparate nature of this field, this living scoping review aimed to identify new OHBCS and report their findings.

A three-step search strategy was adopted. Studies were searched using the databases PubMed, Embase, Web of Science, and Scopus, along with the grey literature with no language restrictions. Two independent reviewers screened the studies. OHBCS included those with baseline data collection during pregnancy or within the first year of the child's life or linked future oral health data to exposures during either of these two life stages.

Of the 5374 records, 32 new OHBCS from 16 countries (Northern Ireland and Scotland as part of the UK), comprising 184 studies, were identified. These were categorized as OHBCS with a single oral health publication (n = 17), OHBCS with two or more oral health publications (n = 10), cohorts nested within interventional studies (n = 2) and data linkage cohorts (n = 3). Most of the OHBCS (66%) were established in very high Human Development Index (HDI) countries. OHBCS, with a single publication, included participants from birth to 15, with participation rates ranging from 14.6% to 100.0%. Similarly, those with two or more publications, nested interventions, or data linkage had participation rates ranging from 13.3% to 99.4% by age 6. The most commonly reported primary outcomes were dental caries (n = 18), enamel defect/hypomineralization (n = 9), and oral microbiome (n = 5).

The review highlights the rapid growth of new OHBCs, particularly in very high-human development countries and identifies emerging approaches in genetics and microbiome research. Efforts should encourage new OHBCS in low- and middle-income countries and support engagement in pooled analyses. Initiatives by GLOBICS (Global Consortium of Oral Health Birth Cohort Studies) may help define critical actions to leverage new and well-established OHBCS.