Targeted therapy for threatened preterm labor based on sonographic measurement of the cervical length: a randomized controlled trial
Article first published online: 3 JAN 2007
Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound in Obstetrics & Gynecology
Volume 29, Issue 1, pages 47–50, January 2007
How to Cite
Alfirevic, Z., Allen-Coward, H., Molina, F., Vinuesa, C. P. and Nicolaides, K. (2007), Targeted therapy for threatened preterm labor based on sonographic measurement of the cervical length: a randomized controlled trial. Ultrasound Obstet Gynecol, 29: 47–50. doi: 10.1002/uog.3908
- Issue published online: 3 JAN 2007
- Article first published online: 3 JAN 2007
- Manuscript Accepted: 9 NOV 2006
- The study was funded by The Fetal Medicine Foundation (Registered Charity 1037116)
- cervical length;
- preterm labor;
False positive diagnosis of preterm labor is common. As a consequence, medications including corticosteroids to promote fetal lung maturity and tocolysis are prescribed unnecessarily. We tested the hypothesis that management of threatened preterm labor based on measurement of cervical length by ultrasonography can reduce the number of women who receive inappropriate treatment.
Forty-one women with threatened preterm labor for whom a clinical decision was made to prescribe antenatal corticosteroids and tocolysis were randomized to have their cervical length measured by transvaginal ultrasound (n = 21) or to receive therapy as planned (n = 20). Fourteen women in the ultrasound group had a cervix longer than 15 mm and the therapy was withheld, while the other seven with a short cervix were managed in the same way as the control group.
Three women (14%) in the ultrasound group were treated inappropriately with antenatal corticosteroids because they remained undelivered for more than a week. This compared favorably with the control group where 18 out of 20 (90%) received corticosteroids unnecessarily (relative risk (RR) 0.16; 95% confidence interval (CI), 0.05–0.39). Tocolysis was given to only seven women (33.3%) in the ultrasound group compared with 20 (100%) in the control group (RR 0.3; 95% CI, 0.15–0.54). There were no babies in either group who were born prematurely without being given a full course of antenatal corticosteroid therapy.
Women with threatened preterm labor and cervical length more than 15 mm should not receive tocolysis. The issue of the safety of withholding corticosteroid therapy in this clinical scenario warrants further study. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.