Uterine Cervical Length Measurement to Reduce Length of Stay in Patients Admitted for Threatened Preterm Labor: A Randomized Trial

Abstract

Objective: To study whether knowledge of cervical length (CL) is useful in reducing the length of hospital stay in women admitted because of threatened preterm labor. Methods: We performed a single-center, parallel, randomized trial at the Hospital Clínic of Barcelona. Inclusion criteria were single pregnancy, gestational age (GA) between 24⁺⁰ and 35⁺⁶ weeks, Bishop score <6, no parturition within 24-48 h after admission, and no clinical signs of chorioamnionitis, vaginal bleeding, or nonreassuring fetal status. CL measurement was performed 24-48 h after admission. In the control group, the patient and the physician in charge were blinded. In the study group, this information was given; if CL was >25 mm, early discharge within 12-24 h from randomization was recommended. Length of hospital stay was the main outcome. Results: After randomization, 149 patients had complete follow-up (control group, n = 74; study group, n = 75). The mean (SD) length of stay was significantly shorter - 3.0 (2.2) vs. 4.0 (2.0) days (p = 0.004) - in the study group, with a higher proportion of women remaining hospitalized ≤3 days (relative risk [95% confidence interval] 0.43 [0.26-0.70]), with no differences in GA at delivery or preterm birth rate. Conclusions: Knowledge of CL in women admitted because of threatened preterm labor is useful in reducing length of stay, with no impact on GA at delivery or preterm birth rate.

Cervical Length Ultrasound for the Evaluation of Preterm Labor: A Survey of National Use and Review of Evidence

“…20 Another individual study that randomized physicians to the knowledge of CL/fFN versus standard care (no knowledge of CL/fFN) reported that physician knowledge that the cervix was long (CL > 30 mm) shortened the time of evaluation for PTL. 9 Most recently, a randomized trial demonstrated reduced length of stay (3 vs. 4 days) with the use of CL ultrasound in PTL evaluation 21 ( Table 3 ). Finally, a cost-effectiveness study from the Netherlands compared various PTL management strategies including universally treating all who present with PTL versus selectively treating based on CL/fFN and found that the most cost-effective strategy for the treatment of PTL was when CL was <15 mm or when CL was 15 to 30 mm and fFN was positive.…”

Is 25 mm the correct mid‐trimester cut‐off for cervical shortening among asymptomatic women?

“…Our results correlate with what is already known in the literature regarding women with SCS. SCS is a well‐known risk factor for PTB, as summarized in a recent Cochrane meta‐analysis, 12 and in additional trials 16,17 . However, data are conflicting regarding the clinical significance of an accidental mid‐trimester finding of ACS in women without risk factors for PTB.…”

ISUOG Practice Guidelines: role of ultrasound in the prediction of spontaneous preterm birth

“…Alfirevic et al 136 . used a cut‐off of 15 mm to guide the decision between active and conservative management, while Palacio et al 137 . opted to use CL ≥ 25 mm as the limit above which a patient could be discharged safely.…”

“…Ness et al 135 used TVS CL cut-offs of < 20 mm for treatment and > 30 mm for discharge from hospital, adding fetal fibronectin (FFN) as a support tool in cases with CL between 20 and 29 mm. Alfirevic et al 136 used a cut-off of 15 mm to guide the decision between active and conservative management, while Palacio et al 137 opted to use CL ≥ 25 mm as the limit above which a patient could be discharged safely. A meta-analysis of 25 studies 138 reported that, for birth within 7 days from presentation, using TVS CL cut-offs of < 15 mm vs < 20 mm, the sensitivity was 59.9% (95% CI, 52.7-66.8%) vs 75.4% (95% CI, 66.6-82.9%), specificity was 90.5% (95% CI, 89.0-91.9%) vs 79.6% (95% CI, 77.1-81.9%), positive likelihood ratio (LR) was 5.71 (95% CI, 3.77-8.65) vs 3.74 (95% CI, 2.77-5.05) and negative LR was 0.51 (95% CI, 0.33-0.80) vs 0.33 (95% CI, 0.15-0.73).…”