Preeclampsia is one of the most serious complications of pregnancy, potentially dangerous for both the health of the mother and the unborn child. It affects an average of 5% of women but still today the predisposition, as well as the early diagnosis, is given only by the anamnesis related to a series of analyzes and symptoms, including high blood pressure and the presence of proteins in the urine .
Now a maternal plasma free RNA assay promises to be used to predict the risk of preeclampsia months before a clinical diagnosis. The new exam was developed by Harvard Medical School and Massachusetts General Hospital, and the results of the first clinical trial have just been published in Nature, opening up new interesting therapeutic perspectives.
“Maternal morbidity and mortality continue to increase and preeclampsia is an important factor in this burden – the researchers write -. Yet the ability to assess pathophysiology to identify risky pregnancies remains elusive”, hence the need to go to search for markers able to say with certainty if you are facing this complication, thus managing to intervene in time with drug therapy and a correct lifestyle.
If pregnancy is difficult, the heart must be protected more carefully
“To demonstrate the ability of RNA to detect patterns of normalcy in pregnancy progression and determine the risk of developing preeclampsia months before clinical diagnosis, we analyzed eight prospectively collected independent cohorts comprising 1,840 pregnancies and 2,539 plasma samples from the database. The signature of cfRna in a single blood draw was shown to have a sensitivity of 75%, which means that it alone could identify three-quarters of the predispositions, with a positive predictive value of 32.3%, which is higher than any another diagnostic method available so far “, explains the researcher Morten Rasmussen, lead author of the trial.
Other studies have already looked for biomarkers circulating in the blood in the case of preeclampsia, but the American researchers have noted that the cfRna in maternal plasma proved to be the earliest and most consistent. So they tried to understand if it also had a stable and replicable clinical value and demonstrated that “its monitoring is able to reliably identify women at risk of preeclampsia months before it becomes clinically evident. These results will allow the development of personalized assessments for every pregnancy, regardless of the prevalences on which we have always based so far “, such as, for example, the familiarity with hypertension, the age and weight of the pregnant woman.
“Improvement in maternal outcomes has been limited by an inability to access fetal tissues as well as a lack of understanding of the molecular phenotypes that identify at-risk individuals prior to the onset of symptoms. more accurate information on the future health of the mother and fetus, thus decreasing maternal and neonatal mortality, “concludes Rasmussen.
“The biology of human pregnancy is difficult to study. The most effective diagnostic procedures are invasive and for ethical and practical reasons it is not possible to repeatedly sample the growing fetus or placenta”, underline the gynecologists. Lydia L. Shook e Andrea G. Edlow, authors of the editorial commenting on the study in Nature. “Unlike cffDna which is used for non-invasive screening of chromosomal abnormalities, cfRna is more dynamic and offers a snapshot of fetal development in real time, providing information on which genes are being expressed, proving to be a valid predictor of placental changes and maternal “.
Although symptoms of preeclampsia typically do not manifest until late pregnancy, “the disease is of early origin and this new approach has been shown to have similar accuracy to second-trimester ultrasound examination, with exciting potential.”
In the placenta there is a mine of data on the health of the baby and the mother
daniele banfi
“We could define preeclampsia as the only true disease of pregnancy. As we know it can have very serious consequences for the mother and the unborn child and the first problem is above all the late diagnosis”, explains the doctor. Elsa Viora, president of Aogoi, the Association of Italian hospital obstetricians and gynecologists. “Various screening methods have been developed, from Doppler of the uterine arteries to Plgf assay in the blood, but the difference will only be made when we are able to identify the women most at risk early on.”
This is why being able to understand this predisposition with a blood test “would be fantastic, a big step forward. Unfortunately, caution is still needed and we do not know if and when this test will become part of clinical practice. But surely the direction is that of which we hope “.
Today, to identify the women most at risk, “we rely on history, age, weight and blood pressure measurement but unfortunately this is not enough. By combining these data with the placental growth factor dosage and ultrasound results we can get a risk calculation, but it is not exhaustive. Low-dose acetylsalicylic acid works as a preventative prophylaxis, but being able to identify the predisposition early and more accurately could save lives. “
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