A new study has revealed that children of stressed mothers grow faster and usually have more teeth by 6 months old.
The study was conducted by researchers from the University of Rochester in the United States, and its results were published in the journal Frontiers in Oral Health on November 18, and the Eurek Alert website wrote about it.
Children have 20 baby teeth, 10 of which are in each jaw. These teeth are important for chewing and speech, and help keep space free for the next set of permanent teeth, consisting of 32 teeth.
Baby teeth begin to grow in the womb in the sixth week of pregnancy, and begin to appear gradually between 6 months and 3 years after birth, with a large difference in this timing, due to genetic and geographical factors, general health, and the nutritional status of the child.
Dr. Ying Ming, an associate professor at the School of Nursing at the University of Rochester in the United States of America and a researcher participating in the study, said, “We show here that high levels of stress-related hormones in the mother – especially cortisol – during late pregnancy are associated with the early appearance of baby teeth in her infant.”
Ying and her colleagues studied a group of 142 mothers in the United States from disadvantaged socioeconomic backgrounds who were pregnant between 2017 and 2022 and enrolled at the University of Rochester Medical Center.
Prenatal stress
In the late second and third trimesters of pregnancy each woman gave a sample of her saliva, where the concentration of the hormones cortisol, estradiol, progesterone, testosterone, triiodothyronine, and thyroxine were measured.
All babies were born full term, and babies of women with high levels of the stress hormone cortisol had more teeth erupted by 6 months.
Infants of mothers with high levels of cortisol had, on average, 4 more teeth at this age than infants of mothers with lower levels of cortisol.
Ying said, “High maternal cortisol levels during late pregnancy may affect fetal growth and mineral metabolism, including regulating calcium and vitamin D levels, both of which are necessary for the mineralization of bones and teeth. Cortisol is also known to affect the activity of osteoblasts and osteoclasts, which are responsible for building, shaping, and remodeling bones.”
“These findings are further evidence that prenatal stress can accelerate biological aging in children, and thus early tooth eruption could serve as an early warning sign of poor oral development and general health in the infant, which is associated with socioeconomic deprivation and prenatal stress,” she added.