The United Nations chose Monday, Oct. 31, as the day to symbolically mark the birth of the world’s 7 billionth person.
Selecting that date — Halloween — for this momentous natal event may be slightly ironic, however, as far as the United States is concerned. For, according to a study published this month in the journal Social Science and Medicine, Halloween is a day when the birth rate mysteriously drops in the U.S.
Here’s reporter Chelsea Whyte’s description of the study in New Scientist magazine:
Rebecca Levy at Yale School of Public Health and colleagues examined 1.8 million U.S. birth records from 1996 to 2006, and found that birth rates dropped by 11.3 per cent on 31 October, when compared with the two-week window surrounding the date. The significant declines in deliveries on Halloween applied to natural births [a 5.3 percent decrease] as well as scheduled caesarean [a 16.9 percent decrease] and induced births [a 18.7 percent decrease].
“The study raises the possibility that the assumption underlying the term ‘spontaneous birth,’ namely, that births are outside the control of pregnant women, is erroneous,” says Levy. She says a psychological influence over hormonal activity may be at work.
“We know that hormones control birth timing, and mothers do often express a desire to give birth on a certain day,” she says. “But the process that allows those thoughts to potentially impact the timing, we don’t know.” More research is needed, she says, to determine the precise ways that thoughts or desires may affect birthing hormones.
Levy and her colleagues also found that births in the U.S. increase on Valentine’s Day. Overall, about 5 percent more babies are born on Feb. 14 than on days that fall within the seven days before or after that date. That Valentine’s Day upsurge in births included a 3.6 percent increase in spontaneous births, a 3.4 percent rise in induced births, and a 12.1 jump in cesarean deliveries.
“The positive connotations of Valentine’s Day may increase a pregnant woman’s will to initiate birth and the negative connotations of Halloween may precipitate her will to resist giving birth,” the authors of the study concluded.