Prenatal Phthalate and BPA Exposure Showed No Clear Link to Hypomineralized Molars

Edited by Dentaltown staff

Prenatal exposure to phthalates and bisphenol A showed no consistent association with hypomineralized second primary molars in a Dutch birth cohort, and the clearest single finding linked one phthalate to lower, not higher, odds of the defect, according to a study published online Oct. 24 in the Journal of Dental Research.

Researchers analyzed 1,160 mother-child pairs from the Generation R Study, a population-based prospective birth cohort in the Netherlands. Maternal urinary concentrations of BPA and 11 phthalate metabolites were measured in each trimester, and children were examined at age 6 using European Academy of Paediatric Dentistry criteria. In all, 10.2% of the children were diagnosed with hypomineralized second primary molars.

In single-exposure models, higher prenatal concentrations of monobenzyl phthalate were associated with lower odds of hypomineralization (odds ratio, 0.76; 95% CI, 0.59–0.97). Second-trimester exposure to metabolites of di-2-ethylhexyl phthalate, or DEHP, showed a nonsignificant trend toward higher odds.

Mixture analyses found a nonsignificant inverse association for overall prenatal exposure (OR, 0.84; 95% CI, 0.63–1.15), with monobenzyl phthalate contributing most, and no overall association for the DEHP mixture.

Results differed by sex. Higher BPA and phthalate concentrations were associated with lower odds in girls, including a BPA odds ratio of 0.70 (95% CI, 0.50–0.98), and with higher odds in boys, based on interaction P values below .10.

The authors noted that second primary molars mineralize between 20 weeks of gestation and 15–17 months of age, and that experimental studies have suggested DEHP and BPA may disrupt enamel formation.

E. Cots of the IDIAPJGol primary care research institute and Universitat Internacional de Catalunya led the study with colleagues at ISGlobal in Barcelona, Erasmus University Medical Center in Rotterdam, and New York University School of Medicine.

The authors concluded that prenatal exposure to phthalates and BPA may influence the development of hypomineralized second primary molars and that early-life exposure to chemical mixtures should be considered in its etiology. The observational design cannot establish causation.

Sources:
Journal of Dental Research, “Prenatal Exposure to Phthalates and Bisphenols in Association with Hypomineralization of Second Primary Molar,” published online Oct. 24, 2026: journals.sagepub.com/doi/10.1177/00220345261490933
National Library of Medicine, PubMed, PMID 42921734: pubmed.ncbi.nlm.nih.gov/42921734