Kesimpulan: Tingkat akurasi panjang serviks meningkat dengan pemeriksaan PAMG-1 dalam memprediksi kelahiran preterm dalam 7 hari dan 14 hari. ......Background: Preterm birth is the leading cause of neonatal morbidity and mortality globally. Mortality and morbidity rates due to preterm birth can be reduced by preventing preterm birth, one of the ways is to utilize an accurate predictor for preterm delivery. As many as 85% of patients with symptoms of preterm labor undergo unnecessary hospitalization Cervical length, one of the widely used predictors of preterm delivery, is operator-dependent and rarely found in primary health care facilities. Another predictor that can be universally used is a biomarker test by detecting Placental Alpha Microglobulin-1 (PAMG-1). PAMG-1 as a predictor of preterm delivery has shown sensitivity, specificity, positive predictive value, negative predictive value rates of 84%, 95%, 77%, and 97%, respectively. Unfortunately, no studies in Indonesia have observed the accuracy of PAMG-1 as a predictor of preterm delivery. Aim: This study aims to investigate the role of PAMG-1 in increasing the accuracy of cervical length as a predictor of preterm delivery in cases of preterm labor. Method: This study is a prospective cohort held in RSCM from March 2019 up to August 2021. Clinical data were acquired from medical records and patient interviews. PAMG-1 data were obtained from vaginal fluid samples taken right after measuring the patients’ cervical length. Samples are then categorized into groups of preterm delivery within 7 days and 14 days, also into groups of cervical length of ≤ 25 mm. Data were then presented in tables and analysed with diagnostic tests to calculate sensitivity, specificity, positive predictive value, and negative predictive value. SPSS 24 is used to analyse the data. Result: PAMG-1 increased the accuracy rate of cervical length in predicting preterm birth for 7 and 14 days. The sensitifity, specificity, positive predictive value, and negative predictive value of combination of PAMG-1 and cervical length ≤ 25 mm were 69%, 98%, 92%, 90%, respectively to predict preterm delivery within 7 days. The sensitifity, specificity, positive predictive value, and negative predictive value of combination of PAMG-1 and cervical length ≤ 25 mm were 56%, 99%, 96%, 83%, respectively to predict preterm delivery within 14 days. Conclusion: The accuracy rate of cervical length increases when combined with PAMG-1 examination to predict preterm deliveries within 7 days and 14 days.