Fetal fibronectin as a predictor of spontaneous preterm labour in asymptomatic women with a cervical cerclage.
OBJECTIVE
To assess the accuracy of fetal fibronectin (fFN) testing for prediction of preterm labour in asymptomatic high-risk women with a cervical cerclage.


METHODS
Retrospective observational study.


METHODS
United Kingdom.


METHODS
Nine hundred and ten asymptomatic women at high-risk of Preterm birth referred to specialist antenatal clinics and undergoing fFN testing between November 1997 and December 2007.


METHODS
Women had fFN tests taken between 23(+0) and 27(+6) weeks' gestation, on one or more occasions.


METHODS
Sensitivity, specificity, positive predictive values and negative predictive values of fFN testing for predicting delivery <30 and <37 weeks were compared in those with and without cerclage.


RESULTS
For delivery <30 weeks' gestation, the specificity of fFN testing was significantly lower in women with cervical cerclage (77% vs 90%; P < or = 0.00001). The sensitivity of the test was similar between the groups (78.6 (no-cerclage) vs 60% (cerclage); P > 0.4). The negative predictive value of the fFN test for delivery <30 weeks was high in both groups (>98%).


CONCLUSIONS
Asymptomatic high-risk women with cerclage in situ are more likely to have a false positive fFN test. The negative predictive value is similar.
Maternal and Fetal Research Unit, King's College London Division of Reproduction and Endocrinology, St Thomas' Hospital, London, UK.
K E
KE
Duhig
M
M
Chandiramani
P T
PT
Seed
A L
AL
Briley
A P
AP
Kenyon
A H
AH
Shennan
D000328:Adult; D015415:Biomarkers / Q000032:analysis; D023802:Cerclage, Cervical; D004812:Epidemiologic Methods; D005189:False Positive Reactions; D005260:Female; D005353:Fibronectins / Q000032:analysis*; D006801:Humans; D008403:Mass Screening / Q000379:methods; D007752:Obstetric Labor, Premature / Q000175:diagnosis* / Q000517:prevention & control; D011247:Pregnancy; D011295:Prenatal Care / Q000379:methods; D011379:Prognosis; D055815:Young Adult
D015415:Biomarkers; C403421:FFN protein, human; D005353:Fibronectins