Selective Reduction in Complicated Monochorionic Pregnancies: A Systematic Review and Meta-analysis of Different Techniques

Abstract Objective This systematic review and meta-analysis aims to compare the perinatal outcomes of complicated monochorionic (MC) pregnancies after selective reduction by radiofrequency ablation (RFA), bipolar cord coagulation (BCC) and interstitial laser (IL). Data sources We searched PubMed, Scopus, and Web of Science, from inception of the database until 26 April 2021. Study eligibility criteria Studies comparing at least two of selective reduction techniques among complicated MC pregnancies and presenting data on perinatal outcomes including gestational age (GA) at procedure, GA at delivery, procedure to delivery interval, preterm premature rupture of the membranes (PPROM), preterm birth (PTB), survival rate and birth weight were eligible. Study appraisal and synthesis methods The random-effect model was used to pool the mean differences or odds ratios (OR) and the corresponding 95% confidence intervals (CIs). Heterogeneity was assessed using the I2 value. Results Ten studies with 734 cases of fetal reduction met the inclusion criteria, of which 9 studies with 674 fetuses were eligible for quantitative synthesis. Comparing RFA vs BCC (n=8 studies): RFA was associated with increased procedure to delivery interval (days) (mean difference 13.42, 95% CI 1.90, 24.94, P 0.02; I2 0.0%), decreased PTB (OR 0.50, 95% CI 0.29, 0.85, P 0.01; I2 3.0%) and decreased PPROM (OR 0.45, 95% CI 0.27, 0.73, P 0.001; I2 0.0%). RFA and BCC had comparable survival rates (OR 0.85, 95% CI 0.54, 1.35, P 0.49; I2 0.0%). RFA vs IL (n=3 studies): There was no significant difference in GA at delivery (P 0.07) or survival (P 0.15). BCC vs IL (n=3 studies): BCC was associated with a higher survival rate (OR 3.21, 95% CI 1.13, 9.10, P 0.03; I2 0.0%), but GA at delivery was comparable between groups (P 0.16). Conclusion This study demonstrates that RFA has a greater procedure to delivery interval and decreased PPROM and PTB compared to BCC. Although there was no difference in GA at delivery for either BCC, RFA or IL, survival was higher with BCC compared to IL.