Women are twice as likely to give birth to a girl if they experienced more stress during conception, according to a study.
Spanish researchers recorded the levels of the stress hormone cortisol in the hair of 108 women between the ninth week of pregnancy and childbirth.
Each hair measurement covered cortisol levels for the previous three months – meaning that the first intake covered the time before and including conception.
The results confirm that fetuses are vulnerable to the effects of maternal stress and that these can play a key role in their development.
Women are twice as likely to give birth to a girl if they experienced more stress during conception, according to a study. Pictured: a newborn baby girl
“The results we found were surprising,” said author and psychologist María Isabel Peralta-Ramírez from the University of Granada.
“They showed that women who gave birth to girls had higher levels of capillary cortisol in the weeks before, during and after the point of conception than those who had boys.
The findings add to growing evidence that the stress experienced by mothers during conception and during gestation can impact the nature of pregnancy, birth and even infant 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, she added, can also trigger “postpartum depression, a greater likelihood of assisted delivery, an increased time to start lactation, or inferior neurodevelopment of the baby six months after birth. birth”.
This study, the team explained, is one of the few that has shown the impact of stress experienced during and even before conception – rather than just the psychological stress experienced during pregnancy.
The findings add to growing evidence that the stress experienced by mothers during conception and during gestation can impact the nature of pregnancy, birth and even infant neurodevelopment. Pictured: A young woman is under stress
According to the researchers, it’s possible their findings could be explained by the body’s “stress system” altering the concentration of sex hormones around the time of conception, but how exactly that would work is unclear.
There is evidence that testosterone could influence the determination of a baby’s sex – and the higher the prenatal stress levels, the higher the female testosterone levels.
Alternatively, the team explained, there is also some evidence that sperm carrying the X chromosome – and therefore the ability to conceive a female fetus – are better able to pass through cervical mucus when faced with adversity.
“There are other possible hypotheses that try to explain this phenomenon,” explained Professor Peralta-Ramírez.
“Among the strongest theories is the idea that there are more male fetal endings for medical reasons during the first weeks of gestation in situations of severe maternal stress,” she said. added.
“Having said that, in light of the design of these studies, it is recommended that the results be further substantiated. “
The full results of the study were published in the Journal of Developmental Origins of Health and Disease.
TIPS FOR A HEALTHY PREGNANCY
The pregnancy health charity Tommy gives a list of actions that would have a positive impact on the health of a pregnancy and the unborn child if done before the mother stops contraception.
Take folic acid
Taking 400 mcg of folic acid per day from two months before stopping contraception can help protect babies develop neural tube defects such as spina bifida.
Smoking during pregnancy causes 2,200 premature births, 5,000 miscarriages and 300 perinatal deaths per year in the UK.
Have a healthy weight
Being overweight before and during pregnancy increases the risk of potentially dangerous conditions such as preeclampsia and diabetes.
Eat healthy and be active
A healthy mother is more likely to give birth to a healthy baby, and both will help maintain a safe body weight.
Talk to your GP if you are taking any medications
Certain medications can affect pregnancy and it is best to see a general practitioner as soon as possible.