Nearly ten percent of babies born in the United States are born preterm, or before they have reached 37 weeks of gestation. Preterm birth is associated with serious health complications including breathing difficulties, vision and hearing impairments, developmental delays, and in some cases, death. Preterm birth is the leading cause of death among babies in the United States.
In addition to the physical and psychological costs of preterm birth, it also has serious financial implications for our health care system. Studies have shown that in the United States alone, preterm birth costs us $26 billion a year.
While there has been research surrounding preterm births, the medical community has been largely unsuccessful at identifying women at risk and developing prevention strategies for those at risk. Approximately 70% of preterm births are spontaneous, and there are very few interventions that can delay delivery once the process has begun.
The scientific world has been searching for the cause of prematurity for years. Thus far, science has pointed to a combination of factors including genetics, environmental stress, psychological stress, infection, and inflammation.
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However, a new landmark study published in the New England Journal of Medicine may change the outlook for premature babies. Utilizing DNA data from over 50,000 women, scientists identified six gene regions linked to these early births.
Up until this point, researchers have estimated that approximately 30-40% of risk for preterm birth was due to genetic factors. However, there was very little data to support this estimation. This new study gathered genetic data from five times as many pregnant women than any previous study surrounding preterm birth.
Of the 50,000 pregnant participants, 43,568 were women of European descent who provided saliva samples through the genetic testing company 23andMe. The study found that of these women, 7.6% gave birth prematurely.
One of the gene regions identified found that the lining of the uterus played a larger than expected role in preterm births. Researchers say this finding may be a target for new medications and research to prevent preterm births.
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Another newly identified gene area points to the mineral selenium as a factor that could impact pregnancy length. A deficiency in this common dietary mineral, found in liver, green vegetables, and meats may contribute to preterm birth.
The comprehensive study was led by Dr. Louis Muglia, co-director at the Perinatal Institute at Cincinnati Children's Hospital and principal investigator of the March of Dimes. Other scientists involved were from the National Institutes of Health, the Research Council of Norway, the Swedish Research Council, and the Bill & Melinda Gates Foundation.
"This is a very exciting discovery that can be expected to lead to the development of new treatments to prevent pregnant women from going into labor too soon and to give more babies a healthy start in life," says Stacey D. Stewart, president of the March of Dimes.