The clinical utility of fetal fibronectin in the prediction of pre-term birth in a low socio-economic setting hospital in Ecuador

Abstract

Background. Pre-term birth is a world wide health problem, and although fetal fibronectin (fFN) testing has proven its clinical utility in developed countries, this remains to be determined in the developing world.Objective. To evaluate the clinical utility of fFN in predicting pre-term birth in a low socio-economic, non-profit hospital setting.Study Design. In this observational study, pregnant women < 37 completed weeks with symptoms suggestive of threatened pre-term labour (painful regular contractions and cervical modifications) were tested with the fFN test, admitted for management and subsequently followed up every 2 weeks until the end of gestation. Delivery rates <35 and <37 weeks and within 7, 14 and 21 days were compared among women with positive and negative results.Results. During the study period, 180 gravids were tested for fFN [52 positives (28.9%) and 128 negatives (71.1%)]. In the positive fFN group, the admission-to-delivery interval was significantly shorter, whereas delivery rates before 35 and 37 weeks and within 7, 14 and 21 days were found to be higher. Neonates delivered from positive fFN women had lower weight and gestational age as well as higher rates of adverse neonatal outcomes and admissions to the intensive care unit. Finally, fFN testing was useful in predicting delivery at less than 37 and 35 weeks (sensitivity: 76, 100%; specificity: 89.2, 76.2%; positive predictive value: 73.1, 23.1%; negative predictive value: 90.6, 100%, respectively) and within 7, 14 and 21 days (sensitivity: 75, 66 and 65.6%; specificity: 78.2, 86.6 and 91.4%; positive predictive value: 34.6, 67.3 and 80.8%; negative predictive value 95.3, 85.9 and 82.8%, respectively).Conclusions. In this low-income healthcare scenario, testing for fFN was effective in assessing the risk of pre-term birth; we propose that testing be implemented as a hospital policy suggesting that negative resulting women be managed in an ambulatory fashion.