American Journal of Obstetrics and Gynecology
Oral plenary session II (fellows plenary)General39: Cervical funneling: effect on gestational length and ultrasound-indicated cerclage in high-risk women
Section snippets
Objective
To assess the relationship between the type of cervical funneling and birth gestational age (GA) in women with prior spontaneous preterm birth (SPTB) and cervical length (CL) < 25 mm enrolled in a randomized intervention trial of ultrasound-indicated cerclage.
Study Design
This is a planned secondary analysis of the NICHD-sponsored cerclage trial. Women with prior SPTB at 17 – 33 6/7 weeks underwent serial vaginal scans between 16 and 22 6/7 weeks. 301 women whose CL was < 25 mm were randomized to receive cerclage or no cerclage. At the qualifying scan for randomization, the presence and type of funnel (U or V-shaped) were recorded.
Results
147 of 301 (49%) had a funnel: 99 were V-shaped (V-F) and 48 were U-shaped (U-F). In univariate analyses, the presence of U-F, but not V-F, was associated with an increased risk of preterm birth < 24 weeks (p= 0.0092), < 28 weeks (p=0.0002), < 35 weeks (p=0.0005), and < 37 weeks (p=0.002). In a multivariable regression model of GA as the dependent variable, U-F (but not V-F) remained significant (p=0.003) after controlling for baseline CL and cerclage group, demonstrating a mean 3 week earlier
Conclusion
The finding of a U-F, but not a V-F, in women with shortened midtrimester CL is associated with a earlier birth GA. The pathophysiologic mechanisms of a U-F appear to be more amenable to cerclage therapy in women with prior SPTB and shortened CL < 25 mm.