Related Experiment Video
Updated: Jun 27, 2026
Guide Wire Assisted Catheterization and Colored Dye Injection for Vascular Mapping of Monochorionic Twin Placentas
Published on: September 5, 2011
The effect of polyhydramnios on cervical length in twins: a controlled intervention study in complicated
Neelam Engineer1, Keelin O'Donoghue, Ruwan C Wimalasundera
1Centre for Fetal Care, Queen Charlotte's and Chelsea Hospital, London, UK. nejengineer@aol.com
Objective:
To test the hypothesis that cervical shortening in polyhydramnios reflects the degree of excess amniotic fluid, and increases with normalisation of amniotic fluid volume.
Study Design:
Prospective cohort study of 40 women with monochorionic twins undergoing interventional procedures between 16-26 weeks. Cervical length was assessed via transvaginal sonography pre-procedure, 1 and 24 hours post-procedure, and results compared between amnioreduction and control procedures. Amniotic fluid index (AFI) was measured pre- and post-procedure.
Results:
Pre-procedural cervical length correlated with AFI (linear fit = 5.07 -0.04x, R(2) = 0.17, P = 0.03) in patients with polyhydramnios (n = 28). Drainage of 2000 ml fluid (range 700-3500 ml), reduced AFI from 42 cm to 21 cm (P<0.001). Their pre-procedural cervical length did not change at one (mean Delta:-0.1cm, 95%CI, -0.4 to 0.2) or 24 hours (0.2 cm, -0.1 to 0.6) after amnioreduction. There was no change in cervical length at control procedures.
Conclusion:
Cervical shortening in twins with polyhydramnios does not appear to be an acute process; cervical length can be measured before or after therapeutic procedures.
