Sumary of Mother’s stress levels during conception could be a determinant of fetal sex:
- The measurement of cortisol in hair samples taken approximately in week 8-10 of pregnancy showed the concentration of cortisol in the pregnant woman for the previous three months (one month per centimeter of hair growth), meaning that it covered the period preceding and after conception..
- María Isabel Peralta Ramírez, the main author of this work and researcher at the UGR’s Department of Personality, Evaluation and Psychological Treatment explains:.
- “The results we found were surprising, as they showed that the women who had given birth to girls presented higher concentrations of hair cortisol in the weeks before, during, and after the point of conception than those who had boys.”.
- In fact, these cortisol concentrations in the hair of mothers who subsequently had girls were almost double those who had boys..
- Consequences of stress There is ample scientific evidence demonstrating the impact of stress on the mother in the processes of pregnancy, birth, and even infant neurodevelopment..
- Related Stories One possible explanation for the results would be that the activation of the “stress system”–the hypothalamus-pituitary-adrenal gland system–which involves an increase in cortisol secretion, modifies the concentrations of sex hormones at the time of conception..
- However, the mechanisms underlying this modification are not clear, because, on the one hand, there is evidence that testosterone could influence the determination of the baby’s sex, since the higher the levels of prenatal stress, the higher the levels of female testosterone..
- On the other hand, there is scientific evidence that sperm carrying the X chromosome (which determines that the baby will be female) perform better at passing through the cervical mucus in circumstances of adversity….