If a woman experienced severe stress during planning or conceiving a child, then she has an increased likelihood of having a girl. This conclusion was voiced by Spanish scientists representing the University of Granada.
Many factors are known that directly or indirectly affect the course of childbirth, childbirth, and the quality of fetal development. In particular, a strong psychological stress in a woman can cause postpartum depression, lead to the need for auxiliary obstetric actions during childbirth, change the beginning of the lactation period and affect the neuropsychic development of the baby during the first six months after birth.
In their new study, scientists asked the question: is there a relationship between stress received not during pregnancy, but before it, and the sex of the unborn baby? Representatives of the Center for the Study of Mind, Brain and Behavior at the University of Granada analyzed hair for the content of the glucocorticoid hormone cortisol. More than a hundred women with confirmed pregnancies were examined before the ninth week. In addition to analyzes, the women underwent psychological testing.
Analysis of the level of cortisol in the biomaterial removed at different periods of the first trimester of gestation showed the content of corticosteroid hormone over the past three months (hair grows by about 10 mm in one month). Thus, scientists could cover the period before and after the conception of the child. As a result, it was found that the concentration of the hormone in the hair of women who later gave birth to girls was 2 times higher than in women who later gave birth to boys.
How to explain this situation? Scientists suggest that it is possible that stimulation of the stress mechanism, which includes the activity of the hypothalamus, pituitary and adrenal glands, and increases the production of cortisol, affects the level of sex hormones during conception. It is a well-known fact that testosterone influences the sex of the unborn baby , the level of which rises at the time of prenatal stress.
The second version that can explain the situation is as follows: male germ cells containing the X chromosome, which determines the female sex of the baby, more easily overcome the barrier of cervical mucus in difficult conditions. If the expectant mother has severe stress and, as a result, hormonal changes occur, then sperm with the X chromosome have a better chance of reaching the egg.
Be that as it may, the researchers confirmed the relationship of stress to the sex of the child, but only if this stress occurred immediately before conception, or during it. The exact mechanism that determines this process is still unknown.
Full information about the study is available on the Universidad de Granada page