A study by an investigator from the Eunice Kennedy Shriver National Institute of Child Health and Human Development NuMoM2b Network casts doubt on routine use of self-collected fetal fibronectin (fFN) and serial transvaginal cervical length (TVCL) measurements in nulliparous women at risk of subsequent spontaneous preterm birth (sPTB). The results were presented during an oral plenary session at the Society for Maternal-Fetal Medicine’s 36th Annual Pregnancy Meeting.
The research was conducted at 8 clinical sites and designed to determine whether universal screening with TVCL and fFN can be used to accurately predict sPTB in nulliparous women. Quantitative fFN was performed on the participants a 3 time points (V1 6-14 weeks; V2 16-22 weeks; V3 22-30 weeks) and TVCL was performed at V2 and V3. Quantitative fFN was run on self-collected swabs and TVCL was measured by certified sonographers. Clinicians were notified if TVCL was <15 mm (n=301) but fFN results were not reported. The investigator used previously described thresholds to evaluate the results and also looked at changes in fFN and TVCL between visits.
Of the 9,352 women with at least one TVCL or fFN measurement and necessary pregnancy outcome data, 460 (4.9%) had sPTV. Of the 301 women with TVCL <15 mm, only 59 received progesterone. Of the women with sPTB, TVCL at V2 identified 34/428 (7.9%) and V3 identified 94/398 (23.6%) using the 25-mm threshold. “The addition of quantitative fFN to TVCL measurement did not increase the predictive ability of TVCL alone,” the author concluded. “The routine use of self-collected quantitative fFN and TVCL to screen for risk of sPTB is not justified in a nulliparous population,” he said.
Esplin M. The use of serial cervical length and quantitative fetal fibronectin to identify nulliparous women at risk of subsequent spontaneous preterm birth. Am J Obstet Gynecol. 2016;214(1);S24