Around 1 million children die each year due to complications from preterm birth (also called premature birth), and 15 million babies are born too early every year, according to the World Health Organization (WHO).

That’s over 10 percent of babies globally.

Now, scientists have developed an experimental test that can potentially predict a woman’s risk of preterm birth earlier and with greater accuracy than the ones currently used. This could help doctors treat more women at risk early enough to prevent serious complications.

The new test screens for 25 signs of inflammation and immune system activation, while also screening for levels of proteins important for placenta development.

In a study, published in the Journal of Perinatology, researchers from University of California, San Francisco School of Medicine and other institutions designed a comprehensive test that predicted both spontaneous and “indicated” premature births (when birth must be induced by the doctor), while also measuring the risk for preeclampsia, which tests currently in use can’t do.

According to researchers, this test could even prevent some cases of preterm birth.

Combined with information on other risk factors, like the mother’s age and income level, the test predicted a woman’s risk for preterm birth with over 80 percent accuracy. For the highest-risk pregnancies (premature birth earlier than 32 weeks) and in women with preeclampsia, the test was nearly 90 percent accurate.

“There are multifactorial causes of preterm birth, and that’s why we felt like we needed to build a model that took into account multiple biological pathways,” said lead author Laura Jelliffe-Pawlowski, PhD, associate professor of epidemiology and biostatistics at UCSF. “The model works especially well for early preterm births and preeclampsia, which suggests that we’re effectively capturing severe types of preterm birth.”

The team also reported that this test could be much less expensive than current tests that gauge preterm birth risk. But the test will need more evaluation before it could become widely available.

Leading cause of death for children under 5 

Prematurity is the leading cause of death in children under the age of 5 years, and, in almost all countries with reliable data, preterm birth rates are increasing.

It’s not just a problem for the developing world. The March of Dimes, using data from the National Center for Health Statistics (NCHS), reports that the U.S. preterm birth rate rose from 9.6 percent of births in 2015 to 9.8 percent in 2016.

“We see that preterm birth rates worsened in 43 states plus the District of Columbia and Puerto Rico, and among all racial/ethnic groups. This is an unacceptable trend that requires immediate attention,” said Stacey D. Stewart, president of the March of Dimes in a statement.

Dr. Cynthia Gyamfi-Bannerman, an OB-GYN at New York-Presbyterian/Columbia University Irving Medical Center, said that the health consequences of premature birth can be serious and lifelong.

“Dependent on how early the baby is born; but there can be long-term effects that include cerebral palsy or developmental delay,” she said.

It isn’t just babies that face serious health risks, says Dr. John Thoppil of River Place OB-GYN.

“The health risks of preterm birth may also affect mothers,” Thoppil told Healthline. “For example, women with preeclampsia, a type of pregnancy high blood pressure, have a greater risk of future cardiovascular disease. Recent data has also shown that just having a history of preterm labor can also confer this same increased cardiovascular risk.”

“Besides the short- and long-term health risks to both moms and babies, preterm birth also burdens our healthcare system. The direct costs are well over 30 billion per year, and when indirect and long-term cost are factored in, may be quite a bit higher,” said Thoppil.

Dr. Angel M. Johnson, FACOG, Female Pelvic Medicine & Reconstructive Surgery, Director of Women’s Health, Greater Boston Urology, LLC, told Healthline that “There are at least four reasons for the increase in preterm birth. First is the increased use of assisted reproductive technologies that help women conceive who previously couldn’t. Next, women are becoming pregnant much later in life. Thirdly, rates of obesity, hypertension, and diabetes (which increase the risk of prematurity) are increasing. Finally, medical interventions are improving; we’re saving more babies than ever before.”

Current tests don’t adequately predict risk

The two commonly used screening tests for preterm birth are transvaginal ultrasound and the fetal fibronectin test (fFN).

Transvaginal ultrasound is used to detect if the length of the cervix has shortened too soon, which increases the risk of preterm labor and premature birth, according to the Mayo Clinic.

“The fFN test checks the amount of fetal fibronectin present in the vagina near the cervix,” Gyamfi-Bannerman said. “It’s used for women who are experiencing the symptoms of preterm labor. It helps determine whether a patient needs closer observation in the hospital or if they can be sent home.”

But, according to a University of Utah Health Sciences study of more than 10,000 women, these two screening tests can’t adequately predict the risk of preterm birth in low-risk women.

Study author Jelliffe-Pawlowski pointed out that earlier treatment can lead to better outcomes.

“If we can get women to the hospital as soon as possible, even if they’ve gone into labor, we can use medications to stave off contractions. This might give her some additional days before she delivers, which can be really important for the baby,” Jelliffe-Pawlowski said in a statement.

According to the National Institutes of Health (NIH), some cases of preterm birth, including those caused by preeclampsia, may be prevented or delayed by taking aspirin or progesterone.