Stress During Pregnancy Can Accelerate The Eruption of The First Teeth

This study investigated whether the stress experienced by the mother during pregnancy can influence the timing of the child's baby teeth erupting. The results show that higher levels of stress-related hormones, such as cortisol, are linked to earlier tooth eruption. This suggests that the mother's emotional and hormonal state during gestation may have a direct effect on infant dental development.

Tooth eruption, which is the process by which teeth appear in the baby's mouth, represents an important phase for the child's overall and oral health. This process does not occur in the same way for all children, as there is a great deal of natural variation.

For example, some children already have two teeth at twelve months, while others may have up to eleven at the same time. This difference may seem like just a curiosity, but it has a real impact.

When teeth appear too early or too late, it can affect the correct alignment of the dental arch, favoring the emergence of problems such as malocclusion, which is when the teeth do not fit together properly when the mouth is closed. Furthermore, alterations in eruption time can affect the quality of tooth enamel and increase the risk of cavities.

There is also recent research suggesting that teeth that emerge very early may indicate that the child is undergoing a more accelerated biological aging process than expected.

Despite the great clinical importance of this process, it is not yet fully understood how the body regulates the exact timing of tooth eruption. It is believed, based on scientific evidence, that both genetic and environmental factors influence this process.

Baby teeth begin to develop during gestation, while the baby is forming inside the womb. This means that this period is sensitive and that anything affecting the mother can also affect the child's dental development.

Previous studies have shown that smoking during pregnancy, inadequate nutrition, and socioeconomic difficulties are associated with alterations in the normal timing of tooth eruption. These more difficult social conditions are generally associated with prolonged stress, and maternal stress during pregnancy has been linked to other childhood dental problems, such as enamel defects and a higher frequency of cavities.

However, to date, studies that have specifically investigated whether prenatal stress interferes with the timing of tooth eruption are still very limited.

For this reason, this study was developed with the aim of exploring this possible relationship. From a biological point of view, stress activates a body system called the hypothalamic-pituitary-adrenal axis. When this system is activated, it increases the production of cortisol, which is known as the stress hormone.

In addition to cortisol, stress can also alter the levels of other important hormones, such as sex hormones and thyroid hormones. These hormones play an essential role in bone development and in regulating vitamin D and calcium levels in the body, which in turn are directly involved in the formation and eruption of teeth.

This biological evidence helps to build a plausible explanation for the idea that maternal stress during pregnancy can affect infant dental development.

To investigate this hypothesis, the study included 142 mother-child pairs. Each child was followed until they were two years old, and dentists recorded how many teeth had erupted at different appointments throughout this period.

To measure prenatal stress, researchers analyzed mothers' medical diagnoses related to anxiety and depression, and collected saliva samples late in pregnancy to measure levels of stress-related hormones, including cortisol, estradiol, progesterone, testosterone, and two thyroid hormones: triiodothyronine and thyroxine.

Afterwards, the results were analyzed using appropriate statistical methods to understand if there was a relationship between the level of these hormones and the number of teeth that emerged at each stage of the child's development.

The results showed that, even within this relatively small group, there was great variation in tooth eruption. At six months, only about fifteen percent of the children had at least one tooth.

However, by twenty-four months, a quarter of them already had all twenty baby teeth. It was observed that higher levels of several maternal hormones during pregnancy, especially cortisol, estradiol, progesterone, testosterone, and triiodothyronine, were associated with a greater number of teeth already erupted at various stages.

The most striking finding was that of cortisol: mothers with higher levels of this hormone during gestation had children with an average difference of up to four more teeth at six months, when compared to the children of mothers with lower levels.

The results of this study suggest that maternal hormone levels during gestation may contribute to explaining why some children have teeth that erupt earlier or later than others.

This reinforces the importance of considering dental development as part of a biological process influenced not only by genetics, but also by the emotional and physiological environment experienced by the mother during pregnancy.

READ MORE:

Prenatal maternal salivary hormones and timing of tooth eruption in early childhood: A prospective birth cohort study

Meng Y, Yang R, Alomeir NGT, Rasmussen JM, Bidlack FB, and Xiao J. 

Frontiers in Oral Health, 6, 1663817. 

https://doi.org/10.3389/froh.2025.1663817

Abstract:

Although the mechanisms underlying tooth eruption are not fully understood, the prenatal maternal milieu, particularly stress exposures, appears to play an important role in dental development. Yet, limited research has investigated the influence of prenatal stress and stress-related hormones on tooth eruption.This study included 142 mother-child dyads from a birth cohort to examine associations between prenatal stress, stress-related hormones, and primary tooth eruption. The number of erupted teeth was assessed by dentists at child visits through 24 months of age. Maternal prenatal depression and anxiety diagnoses were extracted from medical records as a proxy for stress. Stress-related hormone concentrations, including cortisol, estradiol, progesterone, testosterone, triiodothyronine (T3), and thyroxine (T4), were measured from salivary samples collected in late pregnancy. Generalized linear models were used to assess associations between prenatal stress, stress-related hormones, and tooth eruption, adjusting for relevant covariates. Eruption timing varied within our cohort: 15.2% of children had at least one erupted tooth by 6 months, and 25% had all 20 primary teeth by 24 months. Correlations in tooth counts across visits ranged from 0.15 to 0.57. Several prenatal maternal hormones, including cortisol, estradiol, progesterone, testosterone, and T3, were significantly and positively associated with the number of erupted teeth at individual visits (p < 0.05). Particularly, higher prenatal cortisol levels were associated with more erupted teeth at 6 months, corresponding to an average difference of ∼4 teeth between the lowest and highest cortisol levels. Maternal salivary hormone levels in late pregnancy may contribute to variations in primary tooth eruption during the first two years of life.