The effect of fetal fibronectin testing on admissions to a tertiary maternal-fetal medicine unit and cost savings

OBJECTIVE: Fetal fibronectin bedside testing has been proposed as a diagnos tic tool for the accurate diagnosis of preterm labor. The study objective w as to determine whether the introduction of routine fetal fibronectin bedsi de testing affected costs and transfer rates from referral district hospita ls to a tertiary obstetric hospital, as well as direct admissions to a tert iary referral hospital. STUDY DESIGN: We performed an 18-month prospective audit of fetal fibronect in use in 9 referral hospitals and one university maternal-fetal medicine u nit. Data collected were delivery details and cervical dilatation at admiss ion. Cost savings in terms of transport costs for patients with a negative fetal fibronectin result who were not transferred or admitted to the tertia ry center were calculated for interhospital transfer (road ambulance or fix ed-wing retrieval). RESULTS: One hundred fifty-one patients had a presumptive diagnosis of thre atened preterm labor. Forty-five patients had a positive fetal fibronectin result and 106 had a negative fetal fibronectin result (3 with cervical dil atation greater than or equal to 3 cm). Eleven (24%) patients with a positi ve fetal fibronectin result were delivered within 7 days, and 5 (5%) with a negative fetal fibronectin result were delivered within 7 days. One patien t was delivered at 34 weeks, and the remaining patients were delivered at o r after 36 weeks' gestation. All 3 patients with negative fetal fibronectin results with cervical dilatation of greater than or equal to 3 cm were del ivered within 5 days, leaving 2 (1.9%) patients (with closed cervices and n egative fetal fibronectin results) being delivered 5 days after the fetal f ibronectin testing. Ninety percent of the patients admitted to a referral h ospital with threatened preterm labor who had a negative fetal fibronectin result were not transferred; thus an unnecessary transfer was avoided, with cost savings ranging from $30,297 for road and fixed-wing transport. CONCLUSION: A negative fetal fibronectin result is not helpful if cervical dilatation is present, and these patients should be treated as having a hig h risk of preterm delivery. The use of a fetal fibronectin test was associa ted with a 90% reduction in maternal transfer and can substantially reduce the costs and inconvenience associated with unnecessary transfer.