Innovative Blood Test Could Predict Preterm Delivery Risks in Pregnant Women

Recent research conducted by a team at Sinai Health and the University of Toronto has unveiled a promising method for identifying expectant mothers who may face the risk of preterm delivery, potentially paving the way for universal screening protocols.

The findings, published in JAMA Network Open, indicate that low concentrations of placental growth factor (PlGF), a protein crucial for placental health, correlate with the likelihood of preterm birth, specifically before 34 weeks of gestation. This suggests that a straightforward blood test measuring PlGF levels in pregnant women could alert healthcare providers to the need for increased monitoring and tailored delivery strategies.

PlGF is secreted by the placenta into the maternal bloodstream and serves multiple functions, including facilitating the relaxation of maternal blood vessels and regulating blood pressure during pregnancy. It also plays a critical role in preventing blood loss during childbirth.

Research highlights that diminished levels of PlGF are associated with a heightened risk of developing preeclampsia, a serious condition characterized by high blood pressure and potential complications for both mother and baby, necessitating early delivery in a significant number of cases. Additionally, lower PlGF levels contribute to fetal growth restriction, which is a leading cause of medically indicated preterm births.

According to the lead researcher, knowing one's risk level in advance allows for proactive measures to improve pregnancy outcomes. This may include monitoring for elevated blood pressure and potentially initiating antihypertensive medication to manage risks effectively. Furthermore, mothers who initially planned to deliver at smaller facilities might consider transferring to specialized medical centers, which could offer a safer environment for both themselves and their infants.

The study observed that PlGF levels increase as pregnancy progresses, peaking around 28 weeks into gestation. Researchers found that if PlGF levels fall below 100 picograms per milliliter between 24 and 28 weeks, the risk of preterm birth is nearly 50 times greater. Notably, this threshold affects only about 1.5% of the population, indicating that the screening would be highly specific with minimal chances of false positives.

Conducted from 2020 to 2023, the study involved over 9,000 pregnant women who intended to give birth at Mount Sinai Hospital. Participants' PlGF levels were assessed via blood tests during routine screening for gestational diabetes, allowing researchers to correlate these levels with various birth outcomes, including gestational age and birth weight.

Significantly, the research demonstrated that factors such as maternal weight, ethnicity, and previous pregnancy experiences did not influence the relationship between low PlGF levels and preterm birth, making this screening a straightforward and effective tool. Unlike many existing pregnancy screening methods that rely on multiple data points, this test provides clear interpretative results.

Many healthcare facilities across Canada are already equipped with the necessary technology to implement this screening, as PlGF is included in early pregnancy risk assessments for conditions such as Down syndrome.

The researchers express optimism that widespread implementation of this screening could lead to substantial cost savings for healthcare systems. They anticipate that such practices could be established within the next three to five years, enhancing maternal and infant health outcomes.