Algorithm to identify the signs of threatened preterm labour

Aim. To develop the algorithm of identification the signs of threatened preterm labour based on statistical and clinical comparison of modern available diagnostic tests: ultrasound cervicometry and express test-systems for measuring placental α1-microglobulin in cervical secretion.

Methods. The analysis of case histories of patients with a diagnosis of «threatened preterm labor» was performed.

Results. Total of 12 patients had premature labour accounting for 14.12%. In 8 of them placental α1-microglobulin in cervical secretion was positive and only in 5 patients cervical length was ≤20 mm according to ultrasound cervicometry. 4 patients with premature birth (ranging from 48 hours to 7 days) had false-negative test results. 7 (8.2%) patients had a false-positive result of placental α1-microglobulin test, and these patients subsequently had term birth. The sensitivity of the test for placental α1-microglobulin as a marker of premature birth was 66.67%, specificity 95.9%, specificity of ultrasound cervicometry - 47.9%, and sensitivity - 41.7%. Use of the combination of both tests can significantly reduce hyperdiagnosis of threatened preterm labour.

Conclusion. Females with short cervix according to ultrasound cervicometry should reasonably be tested for placental α1-microglobulin in cervical discharge; positive result of this test will be found in those whose probability to give preterm labour during the next 14 days reaches 72.72%, and high prognostic value of a negative test result allows observing the patients in outpatient setting.