Cervical Length and Maximum Vertical Pocket as Predictors of Gestational Age at Delivery in Pregnancies Treated With Selective Fetoscopic Laser Photocoagulation for Severe Twin–Twin Transfusion Syndrome [94

Abstract

OBJECTIVE: To evaluate the effect of polyhydramnios on cervical length and whether cervical length recovery after amnioreduction during selective fetoscopic laser photocoagulation is associated with a greater gestational age at delivery in pregnancies complicated by severe twin–twin transfusion syndrome. METHODS: Retrospective study of pregnancies complicated by severe twin–twin transfusion syndrome treated by selective fetoscopic laser photocoagulation performed between March 2010 and October 2013 at a single center. Preoperative maximum vertical pocket and preoperative and postoperative cervical lengths were measured. The cervical length difference was calculated with a difference of ±3 mm considered no change. Data were analyzed with Spearman and Pearson correlation coefficients calculated for gestational age at delivery. RESULTS: Thirty-nine women were included in the study population. Preoperative (ρ=0.352; P=.035) and postoperative (ρ=0.332, P=.044) cervical lengths were found to have significant positive correlations with gestational age. A subgroup analysis excluding iatrogenic deliveries less than 34 weeks of gestation (n=22) showed a similar correlation with postoperative cervical length, but only a trend toward significance (ρ=0.379; P=.06). Change in cervical length and preoperative maximum vertical pocket were not statistically correlated with gestational age at delivery. The overall survival rate was 74.3% (57/78). There were two fetal survivors in 56.4% (22/39) and at least one survivor in 89.7% (35/39). CONCLUSION: Selective fetoscopic laser photocoagulation remains an effective therapy for pregnancies complicated by severe twin–twin transfusion syndrome. This study is concordant with prior research indicating that cervical length before and after treatment has a significant correlation with gestational age at delivery. However, severity of polyhydramnios and change in cervical length postprocedure were not found to be statistically significant.