According to the study, women who experience the most stress at the time of conception are twice as likely to give birth to a GIRL
- Experts tracked stress levels in 108 women from pre-conception to birth
- They did this by measuring the stress hormone cortisol in hair samples
- Women who were born had higher levels of cortisol around conception
- The results confirm that fetuses are vulnerable to the impact of maternal stress
According to one study, women are twice as likely to give birth to a baby girl if they experienced more stress during the time of conception.
Researchers in Spain recorded the levels of stress hormone cortisol in the hair of 108 women from the ninth week of their pregnancy until delivery.
Each hair measurement covered cortisol levels during the previous three months, i.e. the first intake covered the period prior to conception included.
The findings confirm that fetuses are vulnerable to the effects of maternal stress and may play a key role in their development.
According to one study, women are twice as likely to give birth to a baby girl if they experienced more stress during the time of conception. In the picture: a newborn baby girl
“The results we found were amazing,” said the author and paper psychologist María Isabel Peralta-Ramírez of the University of Granada.
“They showed that women who had given birth to girls had higher concentrations of hair cortisol in previous weeks, during and after the time of conception than those who had children.”
The findings add to the growing evidence that the stress experienced by mothers during conception and during pregnancy can have an impact on the nature of pregnancy, childbirth, and even child neurodevelopment.
“Our research group has shown in numerous publications how psychological stress in the mother generates a greater number of psychopathological symptoms during pregnancy,” said Professor Peralta-Ramírez.
Stress, he added, can also trigger “postpartum depression, an increased likelihood of assisted childbirth, an increase in the time it takes to start breastfeeding, or lower baby neurodevelopment six months after birth.”
This study, the team explained, is one of the few that has demonstrated the impact of stress felt during and even before conception, rather than just the psychological stress experienced during pregnancy.
The findings add to the growing evidence that the stress experienced by mothers during conception and during pregnancy can have an impact on the nature of pregnancy, childbirth, and even child neurodevelopment. Pictured: A young woman experiences stress
According to the researchers, it is possible that their findings could be explained by the body’s “stress system” that modifies the concentration of sex hormones at the time of conception, but it is not clear how exactly this would work.
There is evidence that testosterone could influence the determination of the sex of the baby and, the higher the prenatal stress levels, the higher the levels of female testosterone.
Alternatively, the team explained, there is also evidence that sperm carrying the X chromosome, and therefore the ability to conceive a female fetus, are better able to pass through cervical mucus in adverse circumstances.
“There are other possible hypotheses that try to explain this phenomenon,” said Professor Peralta-Ramirez.
“Among the strongest theories is the idea that there are more terminations of male fetuses for medical reasons during the first weeks of pregnancy in situations of severe maternal stress,” she added.
“That said, in light of the design of these studies, it is recommended that the results be corroborated in more depth.”
The full findings of the study were published in the Journal of Developmental Origins of Health and Disease.