Top researcher Takashi Yorifuji and his team feel that a major reason for this disparity could be noise pollution. Housewives are more prone to premature births than those who work outside the home, possibly showing the link between continued noise exposure and pre-term births. Women who live close to major thoroughfares also were more prone to high blood pressure as well, also a potential cause for delivering early.
So what can expecting woman who live near a major road do? Outside of moving there aren't a whole lot of choices. Yorifuji says that remaining indoors may help, as does improved diet and quitting smoking.
[Source: Reuters | Image: Corbis/Getty]