Background and objectives: No previous study has been conducted in Nigeria on the role of neutrophil elastase in predicting preterm birth. The present study aimed to determine the role of the neutrophil elastase test in predicting birth in women with preterm labor.
Methods: The present prospective cohort study recruited 83 pregnant women with preterm labor between 28 and 36+6 weeks of gestation, and followed up these subjects for 14 days. The controls comprised 85 pregnant women without preterm labor. The cervicovaginal fluid was collected and tested using the neutrophil elastase test. Then, the sensitivity, specificity, and positive and negative predictive parameters were determined. Afterward, the data were scrutinized using the SPSS arithmetic software (Sort23).
Results: Among the 168 pregnant women analyzed in the present study, 83 pregnant women were assigned to the preterm labor group, and 85 pregnant women were assigned to the control group. Furthermore, among the 83 pregnant women in the preterm labor group, 11 women had spontaneous preterm delivery, leading to a spontaneous preterm birth proportion of 13.3%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the neutrophil elastase test within 14 days post-enrollment were 93.8%, 61.2%, 36.6%, 97.6%, and 67.5%, respectively, for the general population, and 87.5%, 66.7%, 35.0%, 96.3%, and 70.2%, respectively, for subjects at <35 weeks of gestation. The positive and negative likelihood ratios for preterm birth prediction were 2.62 and 0.19, respectively.
Conclusion: The neutrophil elastase test exhibited high predictive accuracy in pregnant women with preterm labor, when compared to the controls, based on the sensitivity and negative predictive value, but this had poor positive predictive values. The neutrophil elastase test may be used as a screening test, but not as a potential predictive test, in the routine clinical setting.
Keywords: Elastase; Neutrophil; Prediction; Preterm labor; Sensitivity.