New York: Shorter mothers are at an increased risk of delivering smaller, premature babies, says a new study, reports IANS. “Our finding shows that a mother’s height has a direct impact on how long her pregnancy lasts,” said Louis Muglia from Cincinnati Children’s Hospital Medical Centre in Ohio, US. “The explanation for why this happens is unclear but could depend not only on unknown genes but also on woman’s lifetime of nutrition and her environment,” Muglia noted. Worldwide, 15 million babies are born preterm, and more than one million die due to complications of an early birth, the study said. Babies who survive an early birth face serious and lifelong health problems, including breathing problems, jaundice, vision loss, cerebral palsy and intellectual delays.