An American research concludes that stressed women are more likely to have daughters: but what are the causes and effects of stress in pregnancy?
Stressed women are more likely to have daughters
There are more and more studies that investigate the effects of maternal stress on the progress of pregnancy. The latest research in this regard was conducted at the Columbia University Vagelos College of Physicians and Surgeons and concluded that stress can affect the development of the fetus and even the sex of the baby. According to the researchers, a stressed mom would be more likely to give birth to one daughter.
Catherine Monk, professor of medical psychology at Columbia University’s Vagelos College of Physicians and Surgeons, and his team considered 27 stress indicators psychosocial, physical and lifestyle related. They got involved 187 pregnant women between the ages of 18 and 45 and the data was collected through questionnaires, diaries and daily medical and physical assessments.
It therefore emerged that:
17% of women were psychologically stressed, with clinically significant levels of depression, anxiety and perceived stress;
16% were physically stressed, with relatively higher daily blood pressure and higher calorie intake than other healthy pregnant women;
67% were in good health.
The study, published in the journal PNAS, the Proceedings of the National Academy of Sciences, concluded that pregnant women suffering from physical and psychological stress have less likely to have a boy. On average they are born about 105 males for every 100 female births, but in the group examined in the research, the ratio of male to female births was 4 to 9 for physically stressed women and 2 to 3 for psychologically stressed mothers, respectively.
In addition, physically stressed mothers with hypertension and excessive caloric intake were more likely to give birth prematurely than non-stressed mothers.
The study also made it possible to highlight other negative effects of stress:
in the group of women with a high level of physical and psychological stress, the fetuses had one reduced heart rate compared to those of non-stressed mothers;
psychologically stressed mothers had more complications during and after childbirth compared to mothers who are only physically stressed.
According to estimates, 30% of pregnant women report psychosocial stress due to tensions and problems at work and also linked to depression and anxiety. This type of stress is associated with an increased risk of premature birth, in turn related to higher rates of infant mortality and physical and mental disorders, such as attention deficit hyperactivity disorder and anxiety in children.
Other researchers have looked at the patterns and effects of stress on population and births after social upheavals, such as the 9/11 terrorist attacks in New York, after which, for example, there was a decline in the number of male births. Studies have shown that males are more vulnerable to adverse prenatal environments, furthermore they have suggested that highly stressed women may be less likely to give birth to a boy due to the extremely early miscarriages of male pregnancies which women in many cases they weren’t even aware.
Catherine Monk explains
What can be done
The researchers also found that what most differentiated the three groups was the amount of social support that a mother received from friends and family during her pregnancy: the more social support a mother received, the greater the likelihood that she would give birth to a son.
Furthermore, when social support was statistically equalized between groups, the effects of stress on preterm birth disappeared.
In short, from the moment you try to get pregnant and then during pregnancy, it is important to surround yourself with a strong social and family network, able to support and help.
Does stress in pregnancy also affect the development of the fetus?
This research focused on psychological aspects and maternal mental health but some research conducted on animal models has shown that stress can affect the mother’s immune system and increase cortisol levels in the uterus, also having effects on fetal development, in particular on that neurological and behavioral.