Women who give birth to daughters have higher levels of the stress hormone cortisol at conception.
- This could result from the change in the concentration of sex hormones during conception, when a person is anxious.
- There is some evidence that testosterone could influence the sex of the baby – and the higher the prenatal stress levels, the higher the female testosterone levels.
The mental state of women at the time of conception of their future baby is not without consequences. And the more stressed you are, the greater the chances of having a girl! In a study published on January 7 in the Journal of Developmental Origins of Health and DiseaseSpanish researchers from the University of Granada suggest that women are twice as likely to give birth to a girl if they were stressed at the time of conception.
Cortisol present at high levels
The researchers studied the levels of cortisol, the stress hormone, in the hair of 108 women between the ninth week of pregnancy and the time of delivery. Analyzes confirm that maternal stress has an influence on fetuses and plays a key role in their development. “The results found are surprising. They showed that women who had given birth to girls had higher concentrations of capillary cortisol in the weeks before, during and after the point of conception than those who had boys.”, says María Isabel Peralta-Ramírez, psychologist and lead author of the study.
Several possible explanations
The reasons for this link between stress and the sex of the future baby is not well understood, but several theories are being studied. The researchers propose that this may be explained by the stress-induced change in sex hormone concentration at the time of conception. Stress would increase levels of testosterone, the male but also female sex hormone. Known as being able to influence the sex of the future baby, it would increase the chances of having a girl.
Another guess is that stress increases the number of male fetal terminations. “There are other possible hypotheses that attempt to explain this phenomenon. One of the strongest theories is the idea that there are more terminations of male fetuses for medical reasons during the first weeks of gestation in situations of severe maternal stress.”, proposes María Isabel Peralta-Ramírez.
Stress, a legacy
This study is not the first to show a parent-child bond through stress. Previous research has found that maternal anxiety increases infant stress. Fathers are also concerned since Finnish scientists have shown how the father’s exposure to stress during his childhood increases the risk of transmission to his child.
.
