Abstract
OBJECTIVE: We sought to assess pregnancy outcome along a continuum of cervical lengths (CLs) >= 25 mm.
STUDY DESIGN: We conducted planned secondary analysis of a randomized cerclage trial of women with prior spontaneous preterm birth 17(0)-34(6/7) weeks. Outcomes of women who maintained CLs >= 25 mm were analyzed. Women with CLs <25 mm randomized to no cerclage comprised an internal comparison group.
RESULTS: Of 1014 screened, 153 had CL <25 mm, and 672 had CL >= 25 mm. Birth <35 weeks occurred in 16% of the >= 25 mm cohort. The relationship between CLs >= 25 mm and birth gestational age was null ( P = .15). In the <25 mm group, progressively shorter CLs predicted birth <35 weeks ( P < .001); this relationship was null in the >= 25 mm group ( P = .17).
CONCLUSION: The continuum of CLs >= 25 mm measured between 16(0/7)-22(6/7) weeks does not predict gestational length in women with prior spontaneous preterm birth.