Neutrophil elastase test shows promise in predicting preterm birth

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

Compared to the controls, the neutrophil elastase test had strong predictive accuracy, in terms of sensitivity and NPV. Therefore, although the positive predictive accuracy was low for preterm delivery, the neutrophil elastase test appears to be a useful bedside tool, which can be employed as a screening test for predicting preterm births in women with premature labor. In regular clinical environments with preterm labor, the neutrophil elastase test may be used as a screening test, rather than as a potential predictive test, when available.