A more effective method to identify pregnant women at risk of preeclampsia

We know that aspirin can prevent most severe cases of preeclampsia, a form of hypertension in pregnancy that can have serious consequences for mother and baby. However, due to the antiplatelet properties of this medicine, doctors cannot prescribe it to all pregnant women. Research published in the journal Hypertension An international team led by Emmanuel Bujold from Laval University proposes a solution to this dilemma. Indeed, the new method they tested to predict the risk of preeclampsia would identify in early pregnancy more than three-quarters of women who will develop severe preeclampsia, requiring delivery before age 34.^e week of pregnancy.

“Preeclampsia is caused by poor implantation of the placenta in the uterus, making it difficult for blood to reach the baby. To compensate, the mother’s blood pressure increases, which can affect the functioning of her kidneys, liver, and brain. The problem is usually diagnosed after 20^e week of pregnancy. When preeclampsia becomes severe, doctors have no choice but to proceed with labor, even if fetal development is not complete,” explains Emmanuel Bugeaud, professor at the Faculty of Medicine at Laval University and researcher at the CHU Research Center in Quebec. – Laval University and obstetrician-gynecologist at the CHU of Quebec.

Fortunately, there is a very effective way to prevent this form of hypertension. “Take aspirin daily from the 11th^e or 12^e week of pregnancy prevents up to 90% of cases of preeclampsia leading to childbirth before the 34th term.^e week of pregnancy. The challenge is to determine as early as possible which pregnant women need to take aspirin,” emphasizes Professor Bujold.

The method currently used in Canada and the United States to identify women at risk of preeclampsia is based on variables such as the mother’s age and weight, whether this is the first pregnancy, and whether we have a multiple pregnancy or not. the mother has high blood pressure or the pregnancy resulted from in vitro fertilization. “With this approach, we give aspirin to more than one in three women, but only identify half of the women who have preeclampsia,” Professor Bujold points out.

Hoping to do more, his team tested a new approach developed in the UK. “It combines medical information about the mother as well as two indirect indicators of how well the placenta has implanted in the uterus. The first, obtained through ultrasound, is a measurement of uterine artery pulsation, and the second is a measurement of blood levels of two proteins associated with pregnancy,” explains the researcher.

To compare the performance of the two predictive tools, the researchers followed 7,325 women recruited between the 11th^e and 14^e week of first pregnancy. Of these, 65 suffered from preeclampsia and 37 were diagnosed.^e week of pregnancy, including 22 severe cases requiring delivery before the 34th term.^e week of pregnancy.

“The method currently used in Canada and the United States would detect 59% of cases of severe preeclampsia and produce a 34% false-positive rate (women unnecessarily prescribed aspirin). The new approach detects 77% of cases of severe preeclampsia, and the false-positive rate is 16%,” summarizes Professor Bujold.

This new approach was tested at the University Hospital of Quebec on more than 2,000 patients. “This made it possible to reduce the birth rate until the 34th by 50%.^e week of pregnancy, emphasizes Professor Bujold. We now hope to be able to test it in a pilot project in Gaspésie. This approach not only ensures a safer pregnancy for mother and child, but also does not generate additional costs for the healthcare system. The cost of caring for a single extremely premature baby can be very high. The savings realized from this new method of screening for preeclampsia will more than cover the cost of its implementation.”

Signatories of the study published in Hypertension These are Paul Gerbi, François Audibert, Jo-Anne Johnson, Nan Okun, Yves Giguère, Jean-Claude Forest, Nils Chaillet, Benoit Masse, David Wright, Louise Ghesquière and Emmanuel Bugeaud.