A placental growth factor level of less than 100 pg/mL during midpregnancy was found to increase the likelihood of early preterm birth by 79.4-fold, according to a recent study.

In the study, published in JAMA Network Open, investigators evaluated the use of placental growth factor (PlGF) screening during midpregnancy to predict early preterm birth (prior to 34 weeks). Conducted at Mount Sinai Hospital in Toronto, the prospective cohort study included 9,037 singleton pregnancies. The findings revealed that a PlGF level of less than 100 pg/mL was associated with a 79.4-fold increased likelihood of early preterm birth. This low PlGF level was present in over 50% of iatrogenic early preterm births and 30% of antepartum stillbirths.

Among the participants, 156 (1.7%) of the patients experienced early preterm birth, including 52 spontaneous and 104 iatrogenic cases. PlGF testing showed high specificity (99.5%) and a negative predictive value of 98.9%. Participants with PlGF levels below 100 pg/mL delivered at a median of 6.1 weeks earlier, with more than 50% giving birth within 50 days of testing. Low PlGF levels were also associated with a higher incidence of preeclampsia (adjusted relative risk [RR] = 11.01) and Cesarean births (adjusted RR = 4.04).

The results indicated that PlGF testing, performed during routine gestational diabetes screening, could potentially serve as a tool for identifying pregnancies at increased risk for early preterm birth, especially those requiring iatrogenic intervention. The researchers called for further studies to confirm these findings and assess the cost-effectiveness of incorporating PlGF screening into prenatal care protocols.

Full disclosures can be found in the published study.