A novel blood test has been developed for pregnant individuals in their first trimester to assess their risk of developing preeclampsia, a potentially life-threatening complication.
This pioneering test, announced by Labcorp, is the first of its kind in the United States and can be administered between the 11th and 14th weeks of gestation, aiding in determining the risk of preeclampsia before the 34th week of pregnancy.
Nevertheless, the introduction of the new test does not alter clinical guidance on preeclampsia, according to the American College of Obstetricians and Gynecologists (ACOG). Some medical professionals are questioning its utility.
Dr. Christopher Zahn, ACOG’s interim CEO and chief of clinical practice and health equity and quality, stated, “It is currently unclear how useful the LabCorp test will be in accurately predicting risk for developing preeclampsia and whether it is appropriate for all pregnant patients.”
Preeclampsia, characterized by elevated blood pressure and high levels of protein in urine or other signs of organ damage, usually manifests after the 20th week of pregnancy. If left untreated, it poses serious risks for both mother and baby.
While there is no cure for preeclampsia aside from delivering the baby, certain severe cases can be managed with medications like antihypertensives.
Various factors contribute to the risk of preeclampsia, including maternal age over 35, first-time pregnancy, obesity, family history, diabetes, high blood pressure, kidney disease, autoimmune diseases, multiple pregnancies, or fertility treatments.
The new screening test assesses the risk of preeclampsia by the 34th week of gestation, providing a comprehensive risk evaluation with up to 90% sensitivity and specificity, according to Labcorp. Sensitivity refers to the test's ability to accurately identify high-risk pregnancies, while specificity indicates its ability to accurately identify pregnancies not at high risk.
Doctors interested in utilizing this screening can discuss it with their patients, order the test, and receive results within a few days.
Dr. Brian Caveney, Labcorp's chief medical and scientific officer, remarked, “This is one more tool in the tool belt for clinicians in the US and beyond to help deliver better maternal outcomes.”
Approximately 1 in 25 pregnancies in the United States is affected by preeclampsia, making it one of the leading causes of maternal mortality.
Before the introduction of the new test, at-risk patients could only screen for preeclampsia risk during the second or third trimester of pregnancy if symptomatic and hospitalized, and even that test was launched just last year.
The first-trimester test is not diagnostic but serves as a risk assessment tool to determine if someone is more likely than average to develop preeclampsia during their current pregnancy.
The screening results can lead to adjustments in prenatal care, such as increased monitoring, home blood pressure checks, avoiding overexertion, or, if recommended, taking low-dose aspirin preventively.
Labcorp is in discussions with health insurance providers to ensure coverage for the test, which has a list price of about $240.
The Risk Assessment Process
Preeclampsia risk also exhibits racial disparities, with Black women in the United States experiencing a 60% higher rate compared to White women. Black women are three times more likely to die from pregnancy-related causes than White women, according to the CDC.
Caveney highlighted, “Preeclampsia is one of the main reasons why there is such a significant disparity in maternal outcomes,” adding that evidence-based screening could contribute to addressing this issue.
The new screening test analyzes four biomarkers associated with preeclampsia risk: placental growth factor (PlGF), pregnancy-associated plasma protein-A (PAPP-A), average arterial pressure, and uterine artery pulsatility index (UtAPI) measured during ultrasound.
Low levels of PlGF and PAPP-A may indicate poor placental development and function, while high arterial pressure and UtAPI levels may signify elevated blood pressure and reduced blood flow in the uterine artery.
Combining maternal factors with biomarkers, such as mean arterial pressure, UtAPI, PlGF, and PAPP-A, significantly improves screening performance, as demonstrated in a 2018 study.
Some medical professionals raise concerns regarding the new screening test's utility and potential risks.
Dr. Christian Pettker, chief of obstetrics at Yale-New Haven Hospital, expressed skepticism, stating, “The utility of the test in managing patients has yet to be proven, and it is not clear that it helps more than it could possibly hurt.”
He emphasized the importance of considering false positives and questioned the accessibility and administration of certain components of the test, such as UtAPI measurement.
Labcorp plans to collaborate with physicians and specialists to address these concerns and ensure accurate risk assessment, even if some components are unavailable.
Eleni Tsigas, CEO of the Preeclampsia Foundation, emphasized the potential impact of such screening tools, highlighting the need for equitable access and education to reduce disparities in maternal and neonatal health outcomes.
By appropriately implementing tools like the first-trimester screening test, surprise cases of preeclampsia could be minimized, potentially improving outcomes for pregnant individuals and their babies.
