Preterm birth is the most common cause of death for children under the age of 5. The genes discovery could help with diagnosis and treatment.

Complications from premature birth can be deadly for infants.

Globally the condition leads to almost 1 million deaths annually, according to the World Health Organization (WHO).

While the risks associated with preterm births are known, the medical community has struggled to decipher why some women were more prone to giving birth before they are due.

A recent study has shed light on this problem by identifying certain genes that appear to be linked to an increased risk for women giving preterm birth, or before 37 weeks’ gestation.

Infants born early are at risk for multiple health conditions, including difficulty breathing, as well as sight and hearing issues.

In the United States, nearly 10 percent of pregnancies end in a preterm birth. Globally, complications related to a preterm birth is the top cause of death for children under the age of 5, according to the WHO.

In a recent study published in the New England Journal of Medicine, researchers from the Cincinnati Children’s Hospital Medical Center and other institutions combed through genetic data and surveys from 23andMe to see if certain genes were linked to a risk for preterm birth.

The team looked at 43,568 women who had given birth. About 97 percent were of European descent.

Researchers found that 7 percent, or 3,331, had given birth prematurely.

They also compared these findings with genetic data from 8,000 Nordic women to decipher which genes were most likely to put women at risk for preterm birth.

They found six genes that fit the description.

“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,” Dr. Louis Muglia, co-director of the Perinatal Institute at Cincinnati Children’s and co-author of the study, said in a statement.

The findings mean researchers can potentially determine which pregnant women are at high risk of giving birth prematurely due to their genetics and take steps to mitigate that risk.

For example, one of the genes can affect levels of an essential element called selenium. Giving women selenium supplements could help mitigate the risk.

Dr. Suhas Kallapur, the chief of the Divisions of Neonatology and Developmental Biology at the David Geffen School of Medicine at the University of California, Los Angeles (UCLA), called the research a “landmark study in the field.”

Kallapur, who worked with some of the researchers at the Cincinnati Children’s Hospital Medical Center but did not work on the study, said that the sheer numbers of women studied was important.

“It sort of used a crowdsourcing kind of approach,” Kallapur told Healthline. “It was an efficient study by doing a crowdsourcing approach.”

Kallapur cautioned that it was still far too early to give women a genetic test to determine their risk of giving birth early. He pointed out the researchers focused on one specific demographic.

But he said this study can be a road map for further research.

“In general with the GWAS [genome-wide association] type study the effects are quite modest usually,” he said. “That’s the case for this condition as well.”

He pointed out genetics alone do not determine if a woman will give birth prematurely.

A woman’s age and underlying health conditions, such as preeclampsia can affect a woman’s risk of giving birth prematurely.

However, Kallapur said this study could be just the beginning, and in the future women may start to get personalized treatment based on their genome.

“It’s entirely possible that one of those types of things we could have in a doctor’s office,” he said. “You enter this information and then you submit a small blood sample and a microchip runs this and interprets the risk.”

With that data, a doctor can advise changes or medication to diminish any inherent risk from the patient’s DNA.

“The doctor can then sit and discuss with you…’These are the lifestyle changes we may want to talk about,’” Kallapur said.