Is there value for serial ultrasonographic assessment of cervical lengths after a cerclage?
OBJECTIVE
The objective of the study was to determine the value of serial ultrasonographic cervical length (CL) measurements after cerclage to predict preterm delivery.


METHODS
Retrospective ultrasonographic and outcome data from singleton pregnancies with cerclage were reviewed. Using transvaginal ultrasound (TVS), overall CL obtained before cerclage placement, 2 weeks after cerclage, and before delivery were compared between women who delivered preterm (less than 37 weeks) and term. The overall CL including CL above (CLA) and below the cerclage (CLB) were compared using the SAS program.


RESULTS
Cerclage was placed at 15.7 +/- 3.6 weeks (mean +/- SD) in 57 women. The overall CL before cerclage, 2 weeks after cerclage, and the last TVS before delivery was not different in preterm and term births. The odds ratio of a measurable CLA for preterm delivery by TVS was 0.87 (0.78 to 0.95, 95% confidence interval). Thirty-two patients (56%) had absent CLA at 26.7 +/- 4.4 weeks. Of these, 16 (50%) were delivered for preterm premature rupture of membranes (PPROM) and chorioamnionitis (sensitivity of 100%, specificity of 61%, positive predictive value of 50%, and negative predictive value of 100%).


CONCLUSIONS
Although the overall cervical length by serial TVS after cerclage did not predict preterm birth, absent CLA is associated with preterm delivery, chorioamnionitis, and PPROM.
Hedriana
Herman L
HL
Sacramento Maternal-Fetal Medicine Medical Group Inc, Sacramento, CA, USA.
Lanouette
Jan M
JM
Haesslein
Hanns C
HC
McLean
Lynn K
LK
D000328:Adult; D023802:Cerclage, Cervical; D054791:Cervical Length Measurement; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011247:Pregnancy; D012189:Retrospective Studies; D013997:Time Factors; D016216:Ultrasonography, Prenatal