The intervention utilizes two sources of data to create an algorithm capable of guiding doctors on the best course of action. The first is a test that analyzes the concentration of two substances in the pregnant woman’s blood: sFlT-1 (soluble tyrosine kinase) and PlGF (placental growth factor). When pre-eclampsia occurs, sFlT-1 levels are high and PlGF levels are reduced when compared to a normal pregnancy. The test measures the relationship between the two, which provides more accurate information about the severity of the disease.
In addition, the study incorporated a World Health Organization (WHO) protocol called fullPIERS (Pre-eclampsia integrated estimate of risk) into the algorithm. It is a model that combines six variables based on symptoms (such as chest pain), vital signs and laboratory tests to identify which patient is at excessive risk and may develop serious complications related to hypertension within two to seven days.
The results of the two assessments inform the doctors of the level of risk. If low, the doctor does not need to interrupt the pregnancy. In this case, they can prescribe preventive treatments such as low dose aspirin and monitor the pregnant woman. During this period, the application of the test and the protocol must be repeated once and twice a week, respectively. However, if both indicators show a high risk, an emergency cesarean section is recommended.
The study tested whether the protocol was effective in prolonging pregnancy and reducing premature births in eight hospitals in Rio de Janeiro, São Paulo and Porto Alegre. The objective was to recruit 1,200 women in these centers, which were randomly selected. As they were chosen, all pregnant women with confirmed or suspected pre-eclampsia who had been admitted to maternity wards prior to 37 weeks of gestation were offered the protocol.
“The new algorithm was well received and used by professionals at the centers,” says Dias. “And we have already noticed a greater adherence to the use of treatments for the prophylaxis of preeclampsia, such as the use of calcium and aspirin.”
“If the technique proves to be effective, we can reduce the number of premature births, which represents a double gain: a higher quality of life for children and less spending on hospitalization for the health system,” says Dias, who is also conducting studies of cost-effectiveness of this process, which should be released soon. “Our dream is to incorporate the new algorithm as a risk assessment for the disease in all health services.”
In addition to evaluating the effectiveness and impacts of the algorithm on prematurity rates, the team created a biobank with blood and urine samples from 4,000 women, collected during prenatal care at three times throughout pregnancy: at the beginning of the pregnancy, between 28 and 32 weeks and at the time of delivery. Samples of pregnant women with pre-eclampsia, who were part of the clinical trial of the two tests, were also added to this repository. “In addition to comparing the samples of pregnant women with and without the disease, we will be able to understand the best approaches to identifying and treating it early,” says Dias. “The bank will also serve as a basis for further studies to deepen our knowledge on the subject.” The goal is to collect samples from 5,000 women.
