Maternal serum level of ACTH as a predictive marker of preterm labor in patients with threatened preterm labor

Abstract

Background: The mechanism of preterm labor is still unknown, the hypothalamo-pitutary adrenal axis of the fetus plays an important role in initiation of labor and also premature activation of this axis was reported in cases of preterm delivery. ACTH is the one the hormone of HPA axis so it increases in cases of preterm labor. Purpose of study: To evaluate the role of maternal plasma ACTH concentration in prediction of preterm delivery in pregnant women presenting with threatened preterm labor. Subject and Methods: this study was conducted on 262 Egyptian pregnant women aged between 17 and 35 years with singleton pregnancies between 28 and 36 completed weeks of gestation that had been diagnosed with threatened preterm labor. Patients were subjected to clinical evaluation (history, examination & ultrasound evaluation), serum samples were collected from all women to measure the level of ACTH. Then the women were divided into 2 groups; group of women who delivered preterm and the other of women who delivered at term. The study compared between the 2 groups regarding the level of ACTH. Results: 61.5% of study population delivered preterm, the median of ACTH level of these women was 23.4 pg/ml compared with 19.3 pg/ml in group of women who delivered at term, this difference in values of hormone between the groups was significant (p-value < 0.001). ROC curve analysis revealed fair predictive value of ACTH for prediction of preterm delivery. At the best cut-off value of ACTH in prediction of preterm labor (>22.6 pg/ml), the sensitivity was 55.28 %, the specificity was 86.14%, positive predictive value was 86.4% and negative predictive value was 54.7%. Conclusion: Maternal plasma ACTH concentration can be used as predictor marker of preterm delivery in pregnant women presenting with threatened preterm labor. Keywords: Threatened preterm labor - Preterm delivery (PTD) - Adrenocorticotropin (ACTH)