Placental alpha microglobulin-1 compared with fetal fibronectin to predict preterm delivery in symptomatic women

Deborah A. Wing, Sina Haeri, Angela C. Silber, Cheryl K. Roth, Carl P. Weiner, Nelson C. Echebiri, Albert Franco, Lanissa M. Pappas, John D. Yeast, Angelle A. Brebnor, J. Gerald Quirk, Aisling M. Murphy, Louise C. Laurent, Nancy T Field, Mary E. Norton

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19 Scopus citations

Abstract

OBJECTIVE: To compare the rapid bedside test for placental a microglobulin-1 with the instrumented fetal fibronectin test for prediction of imminent spontaneous preterm delivery among women with symptoms of preterm labor. METHODS: We conducted a prospective observational study on pregnant women with signs or symptoms suggestive of preterm labor between 24 and 35 weeks of gestation with intact membranes and cervical dilatation less than 3 cm. Participants were prospectively enrolled at 15 U.S. academic and community centers. Placental a microglobulin-1 samples did not require a speculum examination. Health care providers were blinded to placental a microglobulin-1 results. Fetal fibronectin samples were collected through speculum examination per manufacturer requirements and sent to a certified laboratory for testing using a cutoff of 50 ng/mL. The coprimary endpoints were positive predictive value (PPV) superiority and negative predictive value (NPV) noninferiority of placental a microglobulin-1 compared with fetal fibronectin for the prediction of spontaneous preterm birth within 7 days and within 14 days. RESULTS: Of 796 women included in the study cohort, 711 (89.3%) had both placental a microglobulin-1 and fetal fibronectin results and valid delivery outcomes available for analysis. The overall rate of preterm birth was 2.4% (17/711) within 7 days of testing and 4.2% (30/711) within 14 days of testing with respective rates of spontaneous preterm birth of 1.3% (9/703) and 2.9% (20/701). Fetal fibronectin was detected in 15.5% (110/711), and placental a microglobulin-1 was detected in 2.4% (17/711). The PPVs for spontaneous preterm delivery within 7 days or less among singleton gestations (n=13) for placental a microglobulin-1 and fetal fibronectin were 23.1% (3/13) and 4.3% (4/94), respectively (P<.025 for superiority). The NPVs were 99.5% (619/622) and 99.6% (539/541) for placental a microglobulin-1 and fetal fibronectin, respectively (P<.001 for noninferiority). CONCLUSION: Although placental a microglobulin-1 performed the same as fetal fibronectin in ruling out spontaneous preterm delivery among symptomatic women, it demonstrated statistical superiority in predicting it.

Original languageEnglish (US)
Pages (from-to)1183-1191
Number of pages9
JournalObstetrics and gynecology
Volume130
Issue number6
DOIs
StatePublished - Jan 1 2017

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ASJC Scopus subject areas

  • Obstetrics and Gynecology

Cite this

Wing, D. A., Haeri, S., Silber, A. C., Roth, C. K., Weiner, C. P., Echebiri, N. C., Franco, A., Pappas, L. M., Yeast, J. D., Brebnor, A. A., Quirk, J. G., Murphy, A. M., Laurent, L. C., Field, N. T., & Norton, M. E. (2017). Placental alpha microglobulin-1 compared with fetal fibronectin to predict preterm delivery in symptomatic women. Obstetrics and gynecology, 130(6), 1183-1191. https://doi.org/10.1097/AOG.0000000000002367