WHITE PLAINS, N.Y., Aug. 18, 2015 - Shorter mothers have shorter pregnancies, smaller babies, and higher risk for a preterm birth. New research has found that a mother's height directly influences her risk for preterm birth. 
 
 Investigators at the March of Dimes Prematurity Research Center Ohio Collaborative looked at 3,485 Nordic women and their babies, and found that maternal height, which is determined by genetic factors, helped shape the fetal environment, influencing the length of pregnancy and frequency of prematurity. In contrast, birth length and birth weight are mainly influenced by transmitted genes. Preterm birth is the number one killer of newborns in the United States and serious gaps exist between racial and ethnic groups. 
 
 More than 450,000 babies are born too soon in the U.S. and the national preterm birth rate is worse than many other high-resource countries, the March of Dimes says. Worldwide, 15 million babies are born preterm, and more than one million die due to complications of an early birth. Babies who survive an early birth face serious and lifelong health problems, including breathing problems, jaundice, vision loss, cerebral palsy and intellectual delays. 
 
 "A major goal of the nationwide network of March of Dimes prematurity research centers is identifying genes that govern fetal growth and length of pregnancy. That a woman's height influences gestational length, independent of the genes she passes on that determine fetal size, is a major finding by our research networks, and the first of what we expect to be many genetic contributions," said Joe Leigh Simpson, MD, March of Dimes senior vice president for Research and Global Programs. 
 
 "The innovative, team-based model of our prematurity research centers is critical to understanding the unknown causes or preterm birth. This new finding adds one small piece toward solving the much larger puzzle of preterm birth," says Dr. Jennifer L. Howse, president of the March of Dimes. 
 
 The March of Dimes is raising $75 million to support its five prematurity research centers. These unique, transdisciplinary centers bring together the brightest minds from many diverse disciplines -- geneticists, molecular biologists, epidemiologists, engineers, computer scientists, and others -- to work together to find answers to prevent premature birth. In addition to the Ohio Collaborative, the March of Dimes has established research centers at Stanford University School of Medicine in California, at the University of Pennsylvania, at Washington University in St. Louis, and at the University of Chicago, Northwestern University and Duke University. 
 
 "Our finding shows that a mother's height has a direct impact on how long her pregnancy lasts," said Louis Muglia, MD, PhD, the primary investigator of the Ohio Collaborative, and co-director of the Perinatal Institute at Cincinnati Children's Hospital Medical Center. "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." 
 
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 The research paper, "Assessing the Causal Relationship of Maternal Height on Birth Size and Gestational Age at Birth: A Mendelian Randomization Analysis," was published online Aug. 18 by PLoS Medicine. 
 
 The March of Dimes works to improve the health of babies by preventing birth defects, premature birth and infant mortality. The March of Dimes is the leading nonprofit organization for pregnancy and baby health. For the latest resources and information, visit marchofdimes.org or nacersano.org. Visit prematurityresearch.org for more information about the research centers. Find us on Facebook and Twitter. ||||| Boys are slightly more likely to be born premature than girls, and they tend to fare worse, too, says a new report on the health of the world's newborns. 
 
 "This is a double whammy for boys," said Dr. Joy Lawn of the London School of Hygiene & Tropical Medicine, who led the team of researchers. "It's a pattern that happens all over the world." 
 
 The gender difference isn't large: About 55 percent of preterm births in 2010 were male, the report found. Nor is it clear exactly why it happens. 
 
 The finding comes from a series of international studies being published Friday that examine newborn health and prematurity. About 15 million babies worldwide are born too soon, most of them in Africa and parts of Asia where survival is difficult for fragile newborns. Globally, about 1 million babies die as a direct result of preterm birth and another million die of conditions for which prematurity is an added risk, the researchers calculated. 
 
 Friday's report offers some of the first estimates of how many preemie survivors go on to suffer certain disabilities, and found that where these babies are born, and how early, determines their risk. 
 
 Overall, Lawn said about 7 percent of survivors have two of the most burdensome disabilities: neurologic-developmental impairment ranging from learning disabilities to cerebral palsy, and vision loss. 
 
 But the biggest risk is to the youngest preemies, those born before 28 weeks gestation. Worldwide, 52 percent of them are estimated to have some degree of neurodevelopmental impairment, the report found. 
 
 Moreover, the risk of impairment in middle-income countries is double that of wealthy countries like the U.S. 
 
 For example, China is saving more preemies' lives but at the cost of their vision, Lawn said. 
 
 Middle-income countries are missing out on a lesson the U.S. learned the hard way several decades ago, that giving these tiny babies too much oxygen can trigger a potentially blinding condition called retinopathy of prematurity. 
 
 "Disability is not something that's inevitable. It's preventable," she said, calling for improved quality of care including eye checks to prevent or reduce vision loss. 
 
 The March of Dimes reported this month that 11.5 percent of U.S. births now are preterm. That rate is inching down, thanks mostly to fewer babies being born just a few weeks early as standards for elective deliveries have tightened, but it still is higher than in similar countries. 
 
 For the public, the gender difference may be the most surprising finding of Friday's report, although Dr. Edward McCabe of the March of Dimes says pediatric specialists have long noticed that baby boys start out a bit more vulnerable. 
 
 "People are curious about it. We'd like to understand why this occurs," McCabe said. 
 
 One possible reason: Mothers have a higher risk of certain pregnancy complications _ high blood pressure and placenta abnormalities _ when carrying boys, Lawn said. 
 
 And if a boy preemie and a girl preemie are born at the same gestational age, the boy will be at higher risk of death or disability, she said. But Friday's report concluded there is too little information to quantify how big that risk is. 
 
 "Girls walk sooner than boys. They talk sooner than boys. They develop more quickly. That's also true in utero," Lawn said. For a preterm baby, "the difference of a few days maturity between a boy and a girl can mean the difference between major lung complications or not." 
 
 It's not just a prematurity issue. The report found that full-term boys also are more likely than girls to experience other newborn health problems including birth complications. 
 
 Other findings from the studies, funded by the Bill & Melinda Gates Foundation and published in the journal Pediatric Research: 
 
 _In high-income countries _ the U.S., Canada, Australia and most of Europe _ more than 80 percent of preemies both survive and thrive, although babies born even a little premature are more likely than full-term babies to be rehospitalized or have learning and behavioral challenges. 
 
 _In low-income countries, preterm babies are 10 times as likely to die as those in high-income countries, and death is more common than surviving with a serious disability. 
 
 _Aside from preterm birth, other leading causes of death and disability among newborns include birth complications that block breathing; severe jaundice and infections.
– The height and weight of a newborn baby is largely governed by his or her own genes, but it's the height of the mother that's giving researchers a telltale sign, reports the Telegraph. Specifically, shorter women have shorter pregnancies and thus more premature babies, report investigators at the March of Dimes Prematurity Research Center Ohio Collaborative in the journal PLOS Medicine. The team analyzed 3,485 Nordic women and their babies, and found that a woman's height actually shapes the fetal environment, thereby influencing the length of her pregnancy. This has broad health implications around the world, where 15 million babies are born prematurely every year and more than 1 million of them die due to complications of early birth—which include breathing problems, vision loss, and intellectual delays, report researchers in a press release. "That a woman's height influences gestational length, independent of the genes she passes on that determine fetal size, is a major finding by our research networks, and the first of what we expect to be many genetic contributions," one researcher says. (Premature birth is now the world's top killer of children under 5.)