Women with a body mass index in the obese range -- 30 or higher -- are more likely to give birth to twins than are normal weight or underweight women.That’s the conclusion of a new Danish study that also found the twins of obese women were slightly more likely to be opposite-sex than same-sex twins."We do not know the mechanism,” said lead study author Dr. Olga Basso, a research associate professor at the University of Arhus in Denmark. The findings appear in a research letter in the April 7 issue of the Journal of the American Medical Association.
