Fetal fibronectin test predicts delivery before 30 weeks of gestation in high risk women, but increases anxiety

Objective To assess efficacy of cervico-vaginal fetal fibronectin as a predictor of spontaneous preterm birth ina high risk antenatal population, and to evaluate the psychological impact of fetal fibronectin testing.Design An observational study.Setting The antenatal clinic at a tertiary referral hospital.Population One hundred and forty-six pregnant women with known risk factors for spontaneous pretermbirth.Methods Women designated as ‘at risk’ for preterm delivery by clinical history were screened for fetalfibronectin at 24 and again at 27 weeks of gestation. Anxiety levels were assessed by questionnaire andcompared with anxiety levels of 206 low risk women also tested for fetal fibronectin. Fetal fibronectinresults were disclosed to the woman and her clinician.Main outcome measures Maternal anxiety and efficacy of the 24-week fetal fibronectin test to predictdelivery before 30, 34 and 37 weeks of gestation.Results Maternal anxiety was higher pretesting in those at high risk compared with low risk women under-going the test. Among the high risk women, anxiety was raised to clinically significant levels in thosereceiving a positive fetal fibronectin screening test result. In all women, 5%, 9% and 21% delivered <30,<34 or <37 weeks of gestation, respectively. Nine percent (n ¼ 13) tested positive for fetal fibronectin at24weeks.Predictivepowerforfetal fibronectin(24 weeks) was greatestfordelivery<30weeksof gestation,with a likelihood ratio of 15 for a positive test (6/13 positive women delivered before 30 weeks).Conclusions Fetal fibronectin was most efficient as a predictor of preterm spontaneous delivery <30 weeks ofgestation, but was associated with high levels of anxiety.INTRODUCTIONPreterm birth is a major problem worldwide with littlevariation in the incidence in recent decades among devel-oped countries, including the UK.