Red cheeks, a drooling neck—teething babies are usually easy to spot. By the age of one, their mouths will have anywhere from two to eleven teeth, a considerable range influenced by many factors… including maternal stress during pregnancy, concludes a new study published in the journal Frontiers in Oral Health.
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“ Although we know that dental development begins before birth, few studies have closely examined how maternal biology, such as stress hormones, might influence the timing of tooth eruption.", explains to Science and Future Ying Meng, a researcher in pediatric nutrition and health at the University of Rochester (USA) and the lead author of this work, explains that in the womb, the fetus begins to develop the first tissues destined to become its teeth around the sixth week of pregnancy. Previous studies had established a link between prenatal stress and problems such as enamel fragility or the early onset of cavities, and even changes in biological aging. But very few studies had directly examined the influence of stress during pregnancy on the timing of teething." explains Ying Meng, whose work helps to fill this gap.
Four teeth ahead
The link between stress and teeth is cortisol, the main stress hormone. Teeth develop through a natural process involving bone remodeling, hormones, and minerals such as calcium and vitamin D. However, cortisol can influence bone growth and breakdown, as well as how the body uses calcium and vitamin D.“,” explains Ying Meng. “Their results, based on blood tests, are clear: at six months old, the babies of women who produced the most cortisol had four more teeth than those of mothers who produced the least. These results are based on the monitoring of 142 women from their pregnancies, all from disadvantaged backgrounds – and therefore particularly subject to stressful living conditions.”
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Cortisol, genetics, and environment affect the timing of teething
“ We expected that stress hormones might affect teething, but the extent of this effect turned out to be greater than anticipated.“,” Ying Meng responded. “Surprisingly, this link is not found in babies of mothers suffering from depression or anxiety.” This suggests that biological stress signals may be more revealing than clinical diagnosis.", analyzes Ying Meng. Cortisol is not, however, the only factor at play. "DPrevious studies show that genetics still plays a significant role in when baby teeth erupt. Other factors, such as nutrition, birth conditions, and living environment, are also important. Cortisol may contribute to or interact with these effects.", the researcher explains.
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An indicator of early or late development
While understanding the factors that influence the timing of teething is important, it's also a matter of health. If teeth erupt too early or too late, it can affect their growth, alignment, and resistance to decay.“, adds Ying Meng. Some works They also link the delay in teething to a reflection of potentially early or late biological aging, in the same way as the age of puberty. From a research perspective, this study helps us understand how stress during pregnancy affects the development of babies and can help identify early indicators of future health risks."The researcher summarizes. According to the French National Health Insurance, the first teething usually occurs between 4 and 7 months and all the baby teeth are in place before the child is 3 years old.
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