Teeth of babies of stressed mothers come out earlier, study suggests

Maternal stress hormones in pregnancy are linked to earlier tooth eruption, with infants showing about four more teeth on average by six months, new research has revealed.

Researchers studied 142 mothers from socioeconomically disadvantaged backgrounds who were pregnant between 2017 and 2022.

They measured hormone levels in saliva during late pregnancy, including cortisol, sex hormones and thyroid hormones.

University of Rochester researchers then tracked when babies’ milk teeth emerged through regular dental checks at one, two, four, six, 12, 18 and 24 months after birth.

Women with the highest cortisol levels had babies with an average of four more teeth at six months compared with those with the lowest levels.

By six months, 15 per cent of infants had between one and six erupted teeth, while 97.5 per cent had between one and 12 teeth by their first birthday.

The study included mothers from varied backgrounds, with 52 per cent of children identified as African-American, 60 per cent of mothers having a high school education or lower, and 53 per cent employed.

While 36.6 per cent of women had depression or anxiety diagnoses during pregnancy, this was not directly linked to hormone levels or tooth eruption timing.

Dr Ying Meng, associate professor at the School of Nursing, said: “High maternal cortisol during late pregnancy may alter foetal growth and mineral metabolism, including the regulation of levels of calcium and vitamin D, both essential for mineralisation of bone and teeth.

“Cortisol is also known to influence the activity of so-called osteoblast and osteoclast cells, responsible for building up, shaping and remodelling bone.”

The findings suggest prenatal stress accelerates biological ageing in children.

Premature tooth eruption could serve as an early warning sign of compromised oral development and overall health linked to socioeconomic deprivation and prenatal stress.

Researchers also found weaker associations between maternal sex hormones, including oestradiol and testosterone, and greater tooth numbers at 12 months.

Similar links appeared between progesterone and testosterone levels and tooth count at 24 months, and between the thyroid hormone triiodothyronine and teeth at 18 and 24 months.

Meng said: “These results are further evidence that prenatal stress can speed up biological ageing in children.

“Premature eruption of teeth could thus serve as an early warning sign of an infant’s compromised oral development and overall health, associated with socioeconomic deprivation and prenatal stress.

“We still have key questions that need answering, for example which maternal hormones or downstream developmental pathways drive the change in the timing of tooth eruption, what the exact relationship is between accelerated eruption of teeth and biological ageing and development, and what such speeding up says about a child’s general health.”