Biomarker test can improve neonatal outcomes for preterm births

Preterm birth - defined as delivery before the 37^th week of pregnancy - is one of the leading causes of infant deaths in the United States. Babies born prematurely are also at an increased risk of having serious health problems. Yet despite advancements in many areas of obstetrics, little progress has been made to reduce the number of preterm births or improve neonatal outcomes. For the third consecutive year, the March of Dimes Annual Report Card has given the United States a D+ for the country's persistently high preterm birth rate. 

In a new study to be presented today at the Society for Maternal-Fetal Medicine's (SMFM) annual meeting, The Pregnancy Meeting™, researchers will unveil findings that suggest that a biomarker test to identify pregnant people at higher risk of preterm birth significantly improved neonatal outcomes, including reducing infant morbidity as well as reducing admissions to the neonatal intensive care unit (NICU) and the amount of time spent in the NICU.

In a multicenter randomized controlled trial, researchers enrolled 5,018 pregnant people at low risk for preterm birth from 19 centers in the United States. Individuals with factors that increase the risk of preterm birth - such as a prior preterm birth, a short cervix, multiple gestations, or severe medical conditions such as lupus or chronic renal disease - were excluded from the trial thus examining a low-risk population.

The biomarker test, which analyzed a participant's blood, was administered in the middle of the second trimester of pregnancy to identify individuals at higher risk of delivering an infant preterm. The test classified 23.5 percent of participants as higher risk within the preterm birth prevention arm. In addition to the traditional standard of care, individuals identified as high risk were given a low-risk and low-cost regimen of daily vaginal progesterone and low-dose aspirin and also assigned weekly standardized phone calls with a nurse. The remaining lower-risk participants received the usual standard of pregnancy care, which included routine checkups.

In the preterm birth prevention group that was screened and treated if the mother had a higher risk test result, data showed a 20 percent reduction in neonatal morbidity and a 20 percent reduction in NICU admissions. Results also further demonstrated that infants who were admitted to the NICU had a 6-8 percent reduction in the length of stay. 

This study is the first to combine a biomarker test that screened a large segment of the population who do not have the typical risk factors for preterm birth with a targeted treatment plan for those who were identified to be at higher risk and demonstrated dramatic improvements in neonatal outcomes."

Brian Iriye, MD, study's lead author, maternal-fetal medicine subspecialist and managing physician at the High Risk Pregnancy Center, Las Vegas

Iriye is also a past president of SMFM. "These findings suggest a transformative strategy for reducing neonatal complications and I believe has the ability to change the practice of obstetrics and prevent neonatal issues associated with preterm birth."

The abstract was published in the January 2025 issue of Pregnancy, a new open-access journal and the first official journal for the Society for Maternal-Fetal Medicine.