The Effect of Polyhydramnios on Cervical Length in Twins: A Controlled Intervention Study in Complicated Monochorionic Pregnancies

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 postprocedure, 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, R2 = 0.17, P = 0.03) in patients with polyhydramnios (n = 28). Drainage of 2000ml fluid (range 700-3500ml), reduced AFI from 42cm to 21cm (P>0.001). Their pre-procedural cervical length did not change at one (mean Δ:-0.1cm, 95%CI, -0.4 to 0.2) or 24 hours (0.2cm, -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. © 2008 Engineer et al

Inverse linear relationship between pre-procedural cervical length (y) and pre-procedural AFI (x) in group B.

<p>y = 5.07 -0.04x, R² = 0.17, <i>P</i> = 0.03.</p

Mean cervical length was unchanged in the two groups over three time periods: pre-procedure, 1 hour post procedure and 24 hour post procedure.

<p><i>Error</i> bars represent standard deviation.</p

Cervical length measurements with mean Δ 1 hour and 24 hour post procedure

<p>Cervical length measurements with mean Δ 1 hour and 24 hour post procedure</p

Maternal characteristics and indications for procedure

a<p>Data shown as median (range)</p>b<p>Data shown as N (%)</p>c<p>Data shown as mean±SD</p>∗<p>with concomitant amnioreduction</p>#<p>pregnancy complicated by both discordant anomaly and stage III TTTS</p

Perinatal- and procedure-related outcomes following radiofrequency ablation in monochorionic pregnancy.

Objective We sought to assess the efficacy, complication rates, and outcomes for complex monochorionic pregnancies undergoing selective fetal reduction using radiofrequency ablation (RFA). Study Design In this prospective observational study, 100 consecutive cases of selective fetal reduction using RFA were analyzed. All cases were managed at the Centre for Fetal Care at Queen Charlotte's and Chelsea Hospital in London. Indications for offering RFA, details of the procedure, and pregnancy outcomes were collected and analyzed. Results The main indications for RFA were discordant fetal anomaly and twin-twin transfusion syndrome. Overall live birth rate was 78% and the median gestation at delivery was 35.15 weeks. Deliver