According to an American study, researchers found that women who had moderate levels of environmental stress before conception had the longest pregnancies.

Each year, between 50,000 and 60,000 children are born prematurely. A birth is said to be premature when it takes place before the end of the pregnancy, which corresponds to 41 weeks of amenorrhea, as Inserm reminds us. A child is considered premature if it is born before 37 weeks of amenorrhea (WA), or 8½ months of pregnancy.

What is the impact of a premature birth on the newborn? Women who report high levels of stress in the months and even years before conception are more likely to have a shorter pregnancy, according to a new study from UCLA. Indeed, stressed women gave birth to infants whose in utero time was shorter by a week or more. “Every day in the womb is important for the growth and development of the fetus. Premature infants have a higher risk of adverse outcomes at birth and later in life than babies born later, including breast disorders. development and physical health problems, "summarizes Christine Dunkel Schetter, distinguished professor of psychology and psychiatry and lead author of the two studies. The findings of this study were disclosed in the journal Psychoneuroendocrinology.

Telomeres impacted 

 For the purposes of this study, researchers followed 111 mothers and their children from preconception to infancy. The women were from seven counties in North Carolina, one in Illinois, and Washington, DC. Between the ages of 3 and 5, the children provided samples of cells from the inside of their cheeks, from which the researchers extracted DNA, including telomeres. The team was then able to compare the length of childhood telomeres with the stress measurements they took while the children were in utero. Thanks to this data, the researchers also found that a mother's stress before giving birth can accelerate the biological aging of her child. 

Indeed, researchers have found that maternal stress negatively affects the length of a baby's telomeres - the small pieces of DNA at the ends of chromosomes that act as protective caps. Other studies have already linked the presence of shortened telomeres to an increased risk of cancer and cardiovascular disease.

Environmental factors

 "What our research tells us is that we may have early environmental and maternal factors that influence a person's starting point in life, which can cause them to age more quickly," says the Study lead author Judith Carroll, Associate Professor of Psychiatry and Biobehavioural Sciences at the Cousins ​​Center for Psychoneuroimmunology. With this new study, researchers have identified a particularly important period in the third trimester when children are at a higher risk of shortened telomeres. "This allows us to determine the contribution of stress at each of these times on the length of the child's telomeres," says Judith Carroll.

How does maternal stress affect cellular aging? "We have hypotheses. We know that stress can activate inflammation and metabolic activity, which in large amounts can contribute to DNA damage. Telomeres are vulnerable to damage and, if they are not repaired before cell division, they can be shortened by this damage. We know that there is rapid cell replication and we suspect that there is an increased vulnerability to damage during this period, "says the author of the study. These results highlight the need to set up health programs dedicated to the well-being of future mothers.