The Actim Partus test is a diagnostic procedure for assessing the risk of preterm birth (preterm birth marker). The procedure represents a one-step membrane immunoassay that can detect highly specific phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1) from cervical smears by using two monoclonal antibodies. The phIGFBP-1 is a protein released by the decidua cells (nutrient-rich cell of the endometrium; decidua cells contain glycogen (multisugars made of glucose units) and fat), and can be detected in cervical secretions shortly before birth. The increased release of the protein is due to the detachment of the egg membranes from the decidua, allowing phIGFBP-1 to enter the cervical secretion. According to the manufacturer’s information, a positive test result is present at a concentration of 10 µg/l of phosphorylated IGFBP-1.
Indications (areas of application)
- Preterm birth risk assessment in preterm labor – preterm birth is defined as a birth before completion of the 37th week of pregnancy. Often, the infant’s birth weight is less than 2,500 g. The most common cause of preterm birth is urogenital infections (infections of the urinary tract and genital organs) of the mother. Other causes of preterm birth in the literature are pregnancy complications such as placental insufficiency (weakness of the placenta), existing anemia (anemia), or gestosis (pregnancy-related illness). In addition, the role of psychosocial triggers in the occurrence of preterm birth is discussed. Of critical importance in assessing the risk of preterm birth is the negative predictive value of the procedure. Three quarters of all pregnant women presenting with preterm labor do not have a preterm birth. Due to the high negative predictive value (predictive value) of Actim PARTUS, preterm birth can be excluded with a reliability of 92-98.5% in the week after the test.
Before the examination
In the event of the occurrence of preterm labor, Actim PARTUS as a rapid biochemical test is a procedure that can detect a possible preterm birth within a very short time, so that immediate therapeutic measures can be initiated. Even before the examination, the patient should be informed that a positive test result need not be associated with preterm delivery, but only with an increased risk, which should, however, be clarified.
The procedure
Actim PARTUS, as a rapid test method, is based on the detection of phIGFBP-1 in cervical secretions. The marker phIGFBP-1 is ideally suited for predicting preterm delivery in symptomatic patients. Detection (confirmation) of phIGFBP-1 is achieved by the use of an immunochromatography assay. The test allows a qualitative determination of the marker protein. Of decisive importance for the quality of the test is the non-existing influence of urine or seminal plasma on the test result.
After the test
The procedure after performing the diagnostic procedure depends on the test result. Due to the high negative predictive value, a negative test result allows the conclusion of a very low risk of preterm birth, so that no follow-up measures beyond the prenatal care program are required. A positive test result by no means necessarily results in preterm birth, but the risk of preterm birth occurring is significantly increased. Consequently, further diagnostic procedures should be used to clarify a possible premature birth so that any necessary therapy can be initiated without delay.
Possible complications
Since the test procedure is an in vitro test, no complications can occur. An allergic reaction is possible due to sample collection but rarely occurs.
