Quantitative fetal fibronectin and cervical length to predict preterm birth in asymptomatic women with previous cervical surgery.
Quantitative fetal fibronectin testing has demonstrated accuracy for prediction of spontaneous preterm birth in asymptomatic women with a history of preterm birth. Predictive accuracy in women with previous cervical surgery (a potentially different risk mechanism) is not known.



We sought to compare the predictive accuracy of cervicovaginal fluid quantitative fetal fibronectin and cervical length testing in asymptomatic women with previous cervical surgery to that in women with 1 previous preterm birth.



We conducted a prospective blinded secondary analysis of a larger observational study of cervicovaginal fluid quantitative fetal fibronectin concentration in asymptomatic women measured with a Hologic 10Q system (Hologic, Marlborough, MA). Prediction of spontaneous preterm birth (<30, <34, and <37 weeks) with cervicovaginal fluid quantitative fetal fibronectin concentration in primiparous women who had undergone at least 1 invasive cervical procedure (n = 473) was compared with prediction in women who had previous spontaneous preterm birth, preterm prelabor rupture of membranes, or late miscarriage (n = 821). Relationship with cervical length was explored.



The rate of spontaneous preterm birth <34 weeks in the cervical surgery group was 3% compared with 9% in previous spontaneous preterm birth group. Receiver operating characteristic curves comparing quantitative fetal fibronectin for prediction at all 3 gestational end points were comparable between the cervical surgery and previous spontaneous preterm birth groups (34 weeks: area under the curve, 0.78 [95% confidence interval 0.64-0.93] vs 0.71 [95% confidence interval 0.64-0.78]; P = .39). Prediction of spontaneous preterm birth using cervical length compared with quantitative fetal fibronectin for prediction of preterm birth <34 weeks of gestation offered similar prediction (area under the curve, 0.88 [95% confidence interval 0.79-0.96] vs 0.77 [95% confidence interval 0.62-0.92], P = .12 in the cervical surgery group; and 0.77 [95% confidence interval 0.70-0.84] vs 0.74 [95% confidence interval 0.67-0.81], P = .32 in the previous spontaneous preterm birth group).



Prediction of spontaneous preterm birth using cervicovaginal fluid quantitative fetal fibronectin in asymptomatic women with cervical surgery is valid, and has comparative accuracy to that in women with a history of spontaneous preterm birth.
Division of Women's Health, King's College London, Women's Health Academic Center Kings Health Partners, St Thomas' Hospital, London, United Kingdom.
Brooke I
BI
Vandermolen
Division of Women's Health, King's College London, Women's Health Academic Center Kings Health Partners, St Thomas' Hospital, London, United Kingdom.
Natasha L
NL
Hezelgrave
Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Elizabeth M
EM
Smout
Division of Women's Health, King's College London, Women's Health Academic Center Kings Health Partners, St Thomas' Hospital, London, United Kingdom.
Danielle S
DS
Abbott
Division of Women's Health, King's College London, Women's Health Academic Center Kings Health Partners, St Thomas' Hospital, London, United Kingdom.
Paul T
PT
Seed
Division of Women's Health, King's College London, Women's Health Academic Center Kings Health Partners, St Thomas' Hospital, London, United Kingdom. Electronic address: andrew.shennan@kcl.ac.uk.
Andrew H
AH
Shennan
D019540:Area Under Curve; D001826:Body Fluids / Q000737:chemistry; D054791:Cervical Length Measurement; D002584:Cervix Uteri / Q000601:surgery*; D005260:Female; D005322:Premature Rupture of Fetal Membranes; D005333:Fetus / Q000737:chemistry*; D005353:Fibronectins / Q000032:analysis*; D005865:Gestational Age; D006801:Humans; D010298:Parity; D011247:Pregnancy; D047928:Premature Birth / Q000175:diagnosis*; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors; D012680:Sensitivity and Specificity
D005353:Fibronectins
LLETZ; cervical length; cervical surgery; fetal fibronectin; preterm birth