A simple blood test can help identify mothers at risk of preterm birth, potentially leading to a universal screening strategy to prevent complications for both mother and baby, according to a team of US and Canadian researchers.
Researchers from Mount Sinai Hospital and the University of Toronto found that low levels of placental growth factor (PlGF), a protein essential for placental development, are strongly associated with preterm birth—defined as delivery before 34 weeks of gestation. Their findings, published in JAMA Network Open, suggest that a PlGF blood test could enable physicians to monitor high-risk pregnancies more closely and plan timely interventions.
PlGF plays a critical role in maternal blood vessel relaxation and blood pressure regulation, ensuring adequate blood supply to the baby. It also protects the mother from excessive blood loss during delivery. The study linked low PlGF levels to an increased risk of preeclampsia, a severe form of hypertension that often necessitates early delivery. Additionally, fetal growth restriction, another major cause of medically indicated preterm births, was found to be associated with low PlGF levels.
“If you know in advance that you’re high risk, there are ways to improve pregnancy outcomes,” said Rachel Gladstone from Sinai Health. “This could include self-monitoring for high blood pressure and taking antihypertensive medications. Women may also opt for delivery at a tertiary care center instead of a remote location, reducing emergency complications.”
PlGF levels naturally rise as a healthy placenta develops, peaking by 28 weeks. The study found that if PlGF levels fall below 100 picograms per milliliter between 24 and 28 weeks, the risk of preterm birth before 34 weeks increases nearly 50-fold. Since only about 1.5% of pregnant women fall within this range, a PlGF screening test is highly specific, minimizing false-positive results.
Conducted from 2020 to 2023, the study analyzed data from over 9,000 pregnant women. It also revealed that factors like maternal weight and previous pregnancy outcomes did not impact the association between low PlGF levels and preterm birth risk.
This breakthrough suggests that widespread PlGF testing could transform prenatal care, allowing for early interventions that improve pregnancy outcomes and reduce neonatal complications.
