A Common Protein Test Predicts Preeclampsia Risk in Moms with Sickle Cell Disease

Sickle cell disease (SCD) is a blood disorder that predominantly affects Black populations in the USA. One in every 365 Black babies is born with the condition, which can cause pain episodes and affect organ function.¹ SCD also puts pregnant Black women at a higher risk of preeclampsia, a potentially fatal condition for mom and baby that can cause high blood pressure, protein in the urine, pain, and headaches.

Sickle Cell Disease Makes It Harder to Detect Preeclampsia

In women without SCD, measuring levels of a protein called placental growth factor (PlGF) is a well-established method for detecting preeclampsia. Lower levels of PlGF indicate increased risk of the condition. But in women with SCD, levels of this protein are high even outside of pregnancy.

“This has raised the question of whether we can use low placental growth factor levels to predict preeclampsia in this patient population, and our study finds that, yes, we can, and with the same threshold that we use for patients without sickle cell disease,” said Kinga Malinowski, an obstetrician at McMaster University and co-author of the study, in a press release. Malinowski and her colleagues at the University of Toronto and Mount Sinai Hospital published their study in Blood Advances.² The authors hope that their findings will help clinicians anticipate pregnancy complications in women with SCD more effectively.

Validating the Robustness of the Diagnostic Test

In the new analysis, Malinowski and colleagues reviewed pregnancy data from 83 Black women with SCD and 149 healthy controls. They looked at the women’s PlGF levels during pregnancy.

The team found that, as in women without SCD, they could use low levels of PlGF to predict early-onset preeclampsia risk, which occurs before 34 weeks of pregnancy.³ A PlGF threshold of 87 pg/mL at 20–24 weeks predicted early-onset preeclampsia with 100 percent sensitivity and specificity. The researchers noted that the test failed to predict late-onset preeclampsia with high sensitivity and specificity; however, this form of the disease is less severe, and the authors suggest that the inconsistent test performance may hint at distinct disease mechanisms that underlie the two forms of preeclampsia.

The researchers also noted that women with SCD and preeclampsia faced a far higher risk of a condition called maternal vascular malperfusion, a reduction in blood flow that can lead to poor outcomes for the newborn.

“Patients with sickle cell disease are at higher risk for placental complications, so the ability to predict this risk is important for better pregnancy management,” said Malinowski. Establishing that current criteria can reliably identify preeclampsia in high-risk patients will give clinicians more confidence in their ability to predict health outcomes in this vulnerable group. “With appropriate care, it is absolutely possible for patients with sickle cell disease to have a healthy, safe pregnancy for mom and baby.”