WTC terror attacks linked to rise in miscarriagesStudy finds increase in male fetal death in months following 9/11 attacks
The September 11 death toll continues to rise. A new study reports that stress caused by psychological shock from the 2001 World Trade Center terrorist attacks may have led to an increase in male children being miscarried in the United States.
Researchers at the University of California, Irvine recently found (BMC Public Health 2010;10:273) that the fetal death rate for males spiked in September 2001 and that significantly fewer boys were born than expected in December 2001. An earlier study (Hum Reprod 2005 May;20(5):1221–7) had found that fetal death rate for males increased also in October and November of that year.
The UC Irvine study tests the "communal bereavement" hypothesis, which postulates that pregnant women may experience widespread distress even if they never met the deceased, particularly after events in which institutions such as the state fail to maintain safety and security for their members.
"The theory of communal bereavement holds that societies may react adversely to unsettling national events, despite having no direct connection to persons involved in these events," said Tim Bruckner, UC Irvine assistant professor of public health. "Our results appear to demonstrate this, as the shocks of 9/11 may have threatened the lives of male fetuses across the U.S."
Bruckner and colleagues used fetal death data from all 50 states compiled by the National Vital Statistics System between January 1996 and December 2002 to calculate how many male fetal losses would be expected in a normal September. Reviewing all fetal deaths occurring at or beyond the 20th week of gestation, they found male fetal losses rose 3 percent above expected levels in September 2001.
Bruckner told Homeland1 he estimates 120 excess male fetal deaths in the United States to be statistically attributable to the events of 9/11. Pregnant women appear to react to population stressors in ways that jeopardize the trajectory of males in utero, he said.
Bruckner said that witnessing harm to others appears to trigger physiological responses in the witness that mirrors those in the persons harmed. These responses can include the production of corticosteroids implicated in the spontaneous abortion of males.
"Across many species, stressful times reportedly reduce the male birth rate," he said. Though this phenomenon is not fully understood, Bruckner said it's commonly thought to reflect some mechanism conserved by natural selection to improve the mother's overall reproductive success.