Selective reduction in complicated monochorionic pregnancies: a systematic review and meta-analysis of different techniques

Published:October 19, 2021DOI:


      This systematic review and meta-analysis aimed to compare the perinatal outcomes of complicated monochorionic pregnancies after selective reduction by radiofrequency ablation, bipolar cord coagulation, and interstitial laser.

      Data Sources

      We searched PubMed, Scopus, and Web of Science, from the inception of the database up to April 26, 2021.

      Study Eligibility Criteria

      Studies comparing at least 2 selective reduction techniques among complicated monochorionic pregnancies and presenting data on perinatal outcomes, including gestational age at procedure, gestational age at delivery, procedure to delivery interval, preterm premature rupture of membranes, preterm birth, survival rate, and birthweight, were eligible.


      The random-effects model was used to pool the mean differences or odds ratios and corresponding 95% confidence intervals. Heterogeneity was assessed using the I2 value.


      A total of 10 studies with 734 cases of fetal reduction met the inclusion criteria, of which 9 studies with 674 fetuses were eligible for quantitative synthesis. In 8 studies that compared radiofrequency ablation with bipolar cord coagulation, radiofrequency ablation was associated with increased procedure to delivery interval (days) (mean difference, 13.42; 95% confidence interval, 1.90–24.94; P=.02; I2=0.0%), decreased preterm birth (odds ratio, 0.50; 95% confidence interval, 0.29–0.85; P=.01; I2=3.0%), and decreased preterm premature rupture of membranes (odds ratio, 0.45; 95% confidence interval, 0.27–0.73; P=.001; I2=0.0%). Radiofrequency ablation and bipolar cord coagulation had comparable survival rates (odds ratio, 0.85; 95% confidence interval, 0.54–1.35; P=.49; I2=0.0%). In 3 studies that compared radiofrequency ablation with interstitial laser, there was no significant difference in gestational age at delivery (P=.07) or survival (P=.15). In 3 studies that compared bipolar cord coagulation with interstitial laser, bipolar cord coagulation was associated with a higher survival rate (odds ratio, 3.21; 95% confidence interval, 1.13–9.10; P=.03; I2=0.0%), but the gestational age at delivery was comparable between groups (P=.16).


      This study demonstrated that radiofrequency ablation has a greater procedure to delivery interval and decreased preterm premature rupture of membranes and preterm birth than bipolar cord coagulation. Although there was no difference in gestational age at delivery for either bipolar cord coagulation, radiofrequency ablation, or interstitial laser, survival was higher with bipolar cord coagulation than with interstitial laser.

      Key words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to American Journal of Obstetrics & Gynecology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Bebbington M.
        Selective reduction in complex monochorionic gestations.
        Am J Perinatol. 2014; 31: S51-S58
        • Ong S.S.
        • Zamora J.
        • Khan K.S.
        • Kilby M.D.
        Prognosis for the co-twin following single-twin death: a systematic review.
        BJOG. 2006; 113: 992-998
        • Quarello E.
        • Molho M.
        • Ville Y.
        Incidence, mechanisms, and patterns of fetal cerebral lesions in twin-to-twin transfusion syndrome.
        J Matern Fetal Neonatal Med. 2007; 20: 589-597
        • Moher D.
        • Liberati A.
        • Tetzlaff J.
        • Altman D.G.
        • PRISMA Group
        Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
        PLoS Med. 2009; 6e1000097
        • Stang A.
        Critical evaluation of the Newcastle-Ottawa scale for the assessment of the quality of nonrandomized studies in meta-analyses.
        Eur J Epidemiol. 2010; 25: 603-605
        • Hozo S.P.
        • Djulbegovic B.
        • Hozo I.
        Estimating the mean and variance from the median, range, and the size of a sample.
        BMC Med Res Methodol. 2005; 5: 13
        • Roman A.
        • Papanna R.
        • Johnson A.
        • et al.
        Selective reduction in complicated monochorionic pregnancies: radiofrequency ablation vs. bipolar cord coagulation.
        Ultrasound Obstet Gynecol. 2010; 36: 37-41
        • Bebbington M.W.
        • Danzer E.
        • Moldenhauer J.
        • Khalek N.
        • Johnson M.P.
        Radiofrequency ablation vs bipolar umbilical cord coagulation in the management of complicated monochorionic pregnancies.
        Ultrasound Obstet Gynecol. 2012; 40: 319-324
        • van den Bos E.M.
        • van Klink J.M.
        • Middeldorp J.M.
        • Klumper F.J.
        • Oepkes D.
        • Lopriore E.
        Perinatal outcome after selective feticide in monochorionic twin pregnancies.
        Ultrasound Obstet Gynecol. 2013; 41: 653-658
        • Nobili E.
        • Paramasivam G.
        • Kumar S.
        Outcome following selective fetal reduction in monochorionic and dichorionic twin pregnancies discordant for structural, chromosomal and genetic disorders.
        Aust N Z J Obstet Gynaecol. 2013; 53: 114-118
        • Yinon Y.
        • Ashwal E.
        • Weisz B.
        • Chayen B.
        • Schiff E.
        • Lipitz S.
        Selective reduction in complicated monochorionic twins: prediction of obstetric outcome and comparison of techniques.
        Ultrasound Obstet Gynecol. 2015; 46: 670-677
        • Peng R.
        • Xie H.N.
        • Lin M.F.
        • et al.
        Clinical outcomes after selective fetal reduction of complicated monochorionic twins with radiofrequency ablation and bipolar cord coagulation.
        Gynecol Obstet Investig. 2016; 81: 552-558
        • Abdel-Sattar M.
        • Chon A.H.
        • Llanes A.
        • Korst L.M.
        • Ouzounian J.G.
        • Chmait R.H.
        Comparison of umbilical cord occlusion methods: radiofrequency ablation versus laser photocoagulation.
        Prenat Diagn. 2018; 38: 110-116
        • Dadhwal V.
        • Sharma A.K.
        • Deka D.
        • Chawla L.
        • Agarwal N.
        Selective fetal reduction in monochorionic twins: preliminary experience.
        J Turk Ger Gynecol Assoc. 2019; 20: 79-83
        • Shinar S.
        • Agrawal S.
        • El-Chaâr D.
        • et al.
        Selective fetal reduction in complicated monochorionic twin pregnancies: a comparison of techniques.
        Prenat Diagn. 2021; 41: 52-60
        • Lewi L.
        • Gratacos E.
        • Ortibus E.
        • et al.
        Pregnancy and infant outcome of 80 consecutive cord coagulations in complicated monochorionic multiple pregnancies.
        Am J Obstet Gynecol. 2006; 194: 782-789
        • Ting Y.H.
        • Poon L.C.Y.
        • Tse W.T.
        • et al.
        Outcome of radiofrequency ablation for selective fetal reduction before vs at or after 16 gestational weeks in complicated monochorionic pregnancy.
        Ultrasound Obstet Gynecol. 2021; 58: 214-220
        • Paramasivam G.
        • Wimalasundera R.
        • Wiechec M.
        • Zhang E.
        • Saeed F.
        • Kumar S.
        Radiofrequency ablation for selective reduction in complex monochorionic pregnancies.
        BJOG. 2010; 117: 1294-1298
        • Hecher K.
        • Lewi L.
        • Gratacos E.
        • Huber A.
        • Ville Y.
        • Deprest J.
        Twin reversed arterial perfusion: fetoscopic laser coagulation of placental anastomoses or the umbilical cord.
        Ultrasound Obstet Gynecol. 2006; 28: 688-691
        • Ville Y.
        • Hyett J.A.
        • Vandenbussche F.P.H.A.
        • Nicolaides K.H.
        Endoscopic laser coagulation of umbilical cord vessels in twin reversed arterial perfusion sequence.
        Ultrasound Obstet Gynecol. 1994; 4: 396-398
        • Robyr R.
        • Yamamoto M.
        • Ville Y.
        Selective feticide in complicated monochorionic twin pregnancies using ultrasound-guided bipolar cord coagulation.
        BJOG. 2005; 112: 1344-1348
        • Hoffman M.
        • Habli M.
        • Donepudi R.
        • et al.
        Perinatal outcomes of single fetal survivor after fetal intervention for complicated monochorionic twins.
        Prenat Diagn. 2018; 38: 511-516
        • Kumar S.
        • Paramasivam G.
        • Zhang E.
        • et al.
        Perinatal- and procedure-related outcomes following radiofrequency ablation in monochorionic pregnancy.
        Am J Obstet Gynecol. 2014; 210: 454.e1-454.e6
        • Lanna M.M.
        • Rustico M.A.
        • Dell’Avanzo M.
        • et al.
        Bipolar cord coagulation for selective feticide in complicated monochorionic twin pregnancies: 118 consecutive cases at a single center.
        Ultrasound Obstet Gynecol. 2012; 39: 407-413
        • Rossi A.C.
        • D’Addario V.
        Umbilical cord occlusion for selective feticide in complicated monochorionic twins: a systematic review of literature.
        Am J Obstet Gynecol. 2009; 200: 123-129
        • Gaerty K.
        • Greer R.M.
        • Kumar S.
        Systematic review and metaanalysis of perinatal outcomes after radiofrequency ablation and bipolar cord occlusion in monochorionic pregnancies.
        Am J Obstet Gynecol. 2015; 213: 637-643