A new study published in the New England Journal of Medicine, shows that selenium status and preterm births may be linked. A massive DNA analysis from 23andMe of 50,000 pregnant women identified six gene areas, including a newly identified gene area that raises important questions about how a lack of selenium might affect preterm birth risk. The researchers recognized that people living in regions with low selenium in soil and diet, and 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.
“These are exciting findings that could play a key role in reducing newborn deaths and giving every child the chance to grow up smart and strong,” says Trevor Mundel, President of the Global Health Division of the Bill & Melinda Gates Foundation (study funder). “Not only did the study reveal several genes linked to pre-term birth, it also identified a simple, low-cost solution – selenium supplements for expectant mothers – that, if confirmed, could save thousands of lives. It’s a great example of the power of public-private partnership.”
Consequences of Selenium Status and Preterm Births
Preterm birth is defined as any birth occurring before 37 weeks of pregnancy. In addition to the risk of death, babies who survive an early birth often face serious, lifelong health problems, including chronic lung disease, vision and hearing impairment, cerebral palsy, and neurodevelopmental disabilities. The scientific world has been hunting for the causes of preterm birth for decades.
Planning work has started to conduct more-specific testing of selenium levels in pregnant women in low-income nations and areas within the United States. Selenium deficiencies are most likely to occur in people living in regions with low selenium in soil and diet, and people in the U.S. who live in low-income “food deserts.” The amount of selenium found in the soil varies widely around the world. Some European countries actually supplement soil with selenium to make sure foods contain a normal amount of the mineral.
“We have known for a long time that preterm birth is a combination of genetic and environmental factors. Previous research has suggested that about 30 to 40 percent of the risk for preterm birth is linked to genetic factors. This new study is the first to provide robust information as to what some of those genetic factors actually are,” said Louis Muglia, M.D., PhD, co-director of the Perinatal Institute at Cincinnati Children's and principal investigator of the March of Dimes Prematurity Research Center, Ohio Collaborative.
Today’s breakthrough findings lead to several key implications that serve as a beginning point, say the experts.
- The six gene areas identified by the project serve as a launching platform for deeper research, some of which has already begun.
- Potential diagnostic tests, new medications, improved dietary supplements or other changes that could help more women have full-term pregnancies will require several more years of study, the authors say.
In the months and years to come, much more research will be conducted to build upon today’s findings. For example, work is underway to launch studies in Africa and Asia to determine how precisely the gene associations found in this study apply to non-European populations.
Planning work has started to conduct more-specific testing of selenium levels in pregnant women in low-income nations and areas within the United States.
Dr. Muglia noted that the findings will also be part of a March of Dimes Prematurity Research Center database that will allow researchers to study the importance of these genes not only in isolation but in context with other potential factors in preterm birth now under investigation, including:
- The microbiome and inflammation/infection
- Structural integrity of cervix and uterine pacemakers that drive contractions
- Fetal-maternal signaling to initiate labor
- Nutrition and mitochondria
- The molecular basis of social determinants of preterm birth
Source: Zhang, G, Feenstra B, Bacelis J, et al. Genetic Associations with Gestational Duration and Spontaneous Preterm Birth. N Engl J Med. DOI: 10.1056/NEJMoa1612665.