PartoSure Test

• Presence of semen does not interfere with test performance
• Speculum examination and external reader not required
• Results in 5 minutes (1)

The PartoSure Test is a rapid, non-instrumented, qualitative immunochromatographic test for the in vitro detection of placental alpha microglobulin-1 (PAMG-1) in vaginal secretions of pregnant women using a sterile vaginal swab provided in the kit. The device is designed as an aid to rapidly assess the risk of preterm delivery in ≤ 7 days from the time of cervicovaginal sample collection in pregnant women with signs and symptoms of preterm labor, intact amniotic membranes, and minimal cervical dilatation (≤3 cm), sampled between 20 weeks, 0 days and 36 weeks, 6 days gestation.

An accurate risk assessment of preterm birth is clinically important among pregnancies with threatened preterm labor. This is particularly true with respect to both the administration of corticosteroids, which have an optimal benefit within 7 days of administration (1), as well as the transfer of patients to a tertiary care center capable of caring for the birth of a premature infant. Clinical evaluation alone, including the measurement of cervical length and dilatation, is not sufficiently predictive of imminent delivery (2). Similarly, currently available biomarker tests, such as those based on the detection of fetal fibronectin, have extremely poor predictive values for imminent delivery (3). Thus, the accurate prediction of time to delivery in patients with threatened preterm labor remains an important clinical concern. 
 
The high negative and positive predictive values of the PartoSure Test can aid physicians in their overall clinical assessment for pre-term labor, supporting the timely identification of patients that would benefit from available interventions such as antenatal corticosteroids. Additionally, a more accurate identification of these patients may likely reduce the costs associated with unnecessary admissions caused by the poor positive predictive values of existing methods. The test kit is a self-contained system that provides rapid, qualitative results without outside instrumentation or an invasive speculum examination.

The PartoSure Test is a lateral flow, immunochromatographic assay designed to identify the presence of human placental alpha microglobulin-1 (PAMG-1) in amniotic fluid. PAMG-1 was selected as a marker for accurate risk assessment of preterm birth due to its unique characteristics, i.e., its high level in amniotic fluid, low level in blood, and extremely low background level (50-220 picograms/mL) in cervico-vaginal discharge, i.e., the “normal” population. 
The test employs monoclonal antibodies sufficiently sensitive to detect 1 ng/mL of PAMG-1 once eluted into the solvent vial, which is the cut-off concentration for a positive result of the “affected” population. With a dilution of 3-4-fold once eluted into the solvent vial, the cut-off concentration is 13-18 times above the maximum background PAMG-1 concentration.

1. Collect sample of vaginal discharge with sterile collection swab (no speculum required).
2. Rinse specimen swab in solvent vial. Discard swab.
3. Insert amniotic fluid test strip into vial and remove if 2 lines are visible, or at 5 minutes sharp.
4. Results are observed and recorded.

The PartoSure test is for use by healthcare professionals to aid in assessing the risk of preterm delivery in pregnant women when they report signs and symptoms of early preterm labor.

References:

1. Antenatal Corticosteroids Revisited: Repeat Courses. NIH Consensus Statement: NIH, 2000.
2. ACOG Committee on Practice Bulletins- Obstetrics. ACOG Practice Bulletin no. 127: Management of Preterm Labor. Clinical management guidelines for obstetriciangynecologists.
Obstet Gynecol 2012; 119:1308-1316.
3. Berghella V, Hayes E, Visintine J, Baxter JK. Fetal fibronectin testing for reducing the risk of preterm birth. Cochrane Database of Systematic Reviews 2008, Issue 4. Art. No.: CD006843. (Systematic review).