The stress of mothers in the last months of pregnancy seems to be connected to the early eruption of milk teeth in their children: this is the unexpected link discovered by a study published in Frontiers in Oral Healthwhich analyzed nearly 150 U.S. women from disadvantaged socioeconomic backgrounds.
The participants. The authors involved 142 pregnant mothers between 2017 and 2022, and analyzed the levels of various hormones (cortisol, estradiol, progesterone, testosterone, triiodothyronine and thyroxine) starting from saliva samples collected between the end of the second and third month of pregnancy.
The children, all born full-term, were examined by dentists at the ages of one, two, four, six, twelve, eighteen and twenty-four months, to check whether their baby teeth had erupted.
Stress and teeth. At six months of age, 15% of children had between one and six baby teeth, while at one year, 97.5% had between one and twelve teeth. At eighteen months all children had between three and twenty baby teeth, and by two years one in four children had their entire temporary set of teeth.
The children of mothers who had high levels of cortisol, the stress hormone, during pregnancy were those with the highest number of baby teeth erupted within six months. On average, the babies of women with the highest cortisol levels had four more teeth at six months than the babies of the least stressed women.
The effect of cortisol. The reason, explains study coordinator Ying Meng, lies in the fact that high levels of maternal cortisol during an advanced stage of pregnancy can alter fetal growth and mineral metabolism, and with it levels of calcium and vitamin D — both essential for the mineralization of bones and teeth. Cortisol also influences the activity of osteoblasts and osteoclasts, cells responsible for bone formation.
The study, according to Meng herself, still leaves several questions unanswered, such as which maternal hormones determine the timing of tooth eruption, what the precise link is between accelerated tooth eruption and biological aging, and what this anticipation implies for the overall health of the child.
