Exactly what triggers the start of labor remains a mystery, but folklore holds that the weather may influence a baby's arrival. With Hurricane Isaac making landfall, and two other storms brewing in the eastern Atlantic, some may be wondering if the Southeast is due for an increase in births.

Several studies have suggested that drops in barometric pressure can trigger either the onset of labor, or the rupture of the fluid-filled amniotic sac membrane, which is the technical term for a woman's water breaking or starting to leak.

"There's definitely a belief out there," said Dr. Jonathan Schaffir, associate professor of obstetrics and gynecology at Ohio State University College of Medicine. "It's certainly not cut-and-dried, but there is some scientific evidence that changes in pressure can contribute to membrane rupture," he said.

Of the studies that have looked at whether the weather might trigger pregnant women's water to break, two have suggested that it can, while two others have found no association, Schaffir said.