We Now Know Which Genes Cause Preterm Birth
By Lila Sahija
Last week, The New England Journal of Medicine published a groundbreaking study that, for the first time, identifies clear genetic causes of preterm birth.
More than 15 million babies worldwide are born preterm each year – that is, they’re born before 37 weeks of pregnancy. And nearly 1 million of these babies die. In fact, premature birth and its consequences are the leading causes of death for children under 5, and survivors often face life-long health risks ranging from vision and hearing impairments to cerebral palsy.
While medical science has advanced to such a degree that about half of preterm births occur due to known causes, the underlying reasons for the remaining 50% remained mysterious to researchers. This study, drawing from a DNA sample size of more than 50,000 pregnant women around the world, is the first one that is both large enough to be statistically reliable, and diverse enough to represent varied ethnicities and cultures.
The study, “Genetic Associations with Gestational Length and Spontaneous Preterm Birth,” identified six gene regions that influence the length of pregnancy and the timing of birth. With this information, doctors may be able to identify early women with high risks of premature birth, and perhaps find ways to mitigate the risk or, at least, monitor extensively.
The study also showed strong indications that selenium supplements or selenium-rich foods, consumed by expectant mothers in the first weeks of pregnancy, could play a key role in reducing preterm birth. This potential solution could be scaled up to reach millions of women in the world’s poorest and most underserved communities.
Selenium is found concentrated in Brazil nuts, certain green vegetables, and liver and other meats; therefore, people living in low-income countries, as well as people in the U.S. who live in low-income “food deserts” are most at risk of having a lack of selenium in their diets. Providing selenium supplements to pregnant women living in these areas could save thousands – if not millions – of lives. And the best part? Selenium supplements are low-cost and easy to provide.
A sample size of this kind can only be studied when researchers across the world collaborate and share data. This study is a powerful example of the advancements that can be made when scientists around the world pool their findings and work together to interpret them.
An impressive range of researchers from around the world worked together to produce the discoveries. Dr. Louis Muglia, co-director of the Perinatal Institute at Cincinnati Children’s Hospital Medical Center and principal investigator of the March of Dimes Prematurity Research Center—Ohio Collaborative and Dr. Bo Jacobsson of Sahlgrenska Academy, University of Gothenburg, Sweden and the Norwegian Institute of Public Health coordinated the study, with an international team including Ge Zhang, MD, PhD, of the Division of Human Genetics at Cincinnati Children’s; researchers from Norway, Denmark, Finland, Sweden; academic institutions including Yale University and the University of Iowa; and the genetic testing company 23andMe. The Bill & Melinda Gates Foundation was also proud to support this study alongside the March of Dimes, the National Institutes of Health, The Research Council of Norway, and the Swedish Research Council.