Does midtrimester cervical length ≥25 mm predict preterm birth in high-risk women?
OBJECTIVE
We sought to assess pregnancy outcome along a continuum of cervical lengths (CLs) ≥25 mm.


METHODS
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).


CONCLUSIONS
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.
Owen
John
J
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Alabama, Birmingham, AL, USA.
Szychowski
Jeff M
JM
Hankins
Gary
G
Iams
Jay D
JD
Sheffield
Jeanne S
JS
Perez-Delboy
Annette
A
Berghella
Vincenzo
V
Wing
Deborah A
DA
Guzman
Edwin R
ER
D000328:Adult; D023802:Cerclage, Cervical; D054791:Cervical Length Measurement; D002584:Cervix Uteri / Q000000981:diagnostic imaging; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D018566:Pregnancy, High-Risk; D047928:Premature Birth / Q000175:diagnosis*; D016016:Proportional Hazards Models