Oct. 21, 2011 -- Halloween is a day for painted faces, ghoulish frights and candy-induced sugar comas, but not much of a day for having babies, according to new research from Yale's School of Public Health.
Researchers hypothesized that women may hold off or speed up when they go into labor in order to avoid giving birth on holidays with negative connotations, such as Halloween, and aim for giving birth on "positive" holidays, such as Valentine's Day. When they tracked the number of births occurring in the week before and after these holidays between 1996 and 2006, they found that the number of spontaneous births and Caesarean births rose and dipped according to this hypothesis.
Using a sample of all the births occurring in the U.S. during those years, researchers calculated the trends in spontaneous births, induced births and Caesarean. There was a 3.6 increase in spontaneous births and a 12.1 percent increase in Caesarean births on Valentine's Day and a 5.3 percent decrease in spontaneous births and a 16.9 percent decrease in Caesarean births on Halloween.
"This study raises the possibility that the assumption underlying the term 'spontaneous births,' namely, that they are outside the control of pregnant women, is erroneous. For it appears thatpregnant women can expedite or delay spontaneous births, within a limited time frame, in response to cultural representations," the authors wrote.
The fact that the number of Caesarean and induced births rose or fell according to this reasoning may have to do with couples attempting to schedule the birth of their child to occur on or avoid these holidays, according to obstetricians.
"I don't know if it's possible to stop oneself from going into labor for the holidays that people like to avoid, like Halloween," said Dr. Ashlesha Dayal, medical director of labor and delivery at Weiler Hospital in New York City. "I have seen several patients from all different ethnicities who decline induction near a date they consider 'unlucky' according to their calendar."
Even "spontaneous" or unscheduled births seemed to favor Valentine's Day and avoid Halloween, however, the authors noted, which may have something to do with the symbolism of each holiday.
"The symbols of Valentine's Day, such as cherubs, may provide a heightened sense of childbirth's propitiousness. ... However, the symbols of Halloween, such as skeletons, are not only a contrast to the propitiousness of childbirth, they may be perceived as a threat to it," they wrote.
While acute trauma or stress has been noted to increase chances of labor, the idea of women consciously or unconsciously inducing or holding off labor is questionable, obstetricians say.
"We don't really understand what triggers labor," said Dr. Peter Bernstein, director of the Fellowship Program in Maternal Fetal Medicine at the Albert Einstein College of Medicine. "I believe (and this is just my own conjecture) that there is a subconscious factor that can contribute to when women go into labor, [but] I don't think that women can consciously decide when to go into labor."