Loss of Male Fetuses Higher after 9/11

The journal BMC is reporting on a study conducted by the University of California, Irvine that asserts that stressful events, such as the 9/11 tragedy, result in a higher number of fetal deaths in males. 

Lead author Tim Bruckner and his team conducted an intense study of public records from September 2001 and 2002 and compared them with miscarriage and live birth data gathered by the National Vital Statistics System from 1996 until January of 2002.

The secondary sex ratio, which is the male to female birth ratio, declined significantly after the 9/11 attacks, leading the researchers to reason that the intense stress of the event may have precipitated a type of “communal bereavement.”  In such conditions, those affected by an event do not necessarily have to suffer direct loss in order to be severely stressed by it (for a detailed analysis of the study, go to http://www.biomedcentral.com/content/pdf/1471-2458-10-273.pdf).

Negative Impact of Stress Hormones

To support their hypothesis, they also examined live birth data from December 2001; there was a statistically significant decline in the number of male live births, due to fetal loss during the three months following the attacks.   

Other events that create this kind of stress are natural disasters and economic decline; the research team discerned that a perceived lack of security and protection provided by the state or federal government increases the stress felt by pregnant women.

The researchers contend that one reason for the increase in fetal male deaths in such circumstances is because males are more susceptible to the stress hormones of their mothers than females are.  The paper goes on to surmise that in the communal bereavement scenario, witnessing harm to others can trigger an identical response in pregnant women to that of those who have directly lost loved ones.

Maternal Stress and the Unborn Child:  Other Complications

In 2008, a study was presented at the American Thoracic Society's 2008 International Conference in Toronto, which suggests that maternal impact may also negatively affect a baby’s developing immune system. 

The researchers in this instance discovered that babies born to mothers who had experienced excessive stress during gestation gave birth to children who developed asthma and allergy problems later on in their development.   In examining these babies, they discovered that they had a more pronounced reaction to allergens by measuring a certain antibody that is an indicator of immune response.