Selective Reduction in Monochorionic Twins: Key Outcomes
Understanding Clinical Outcomes of Selective Feticide in sFGR
Managing selective fetal growth restriction presents complex clinical challenges for fetal medicine specialists. Consequently, clinicians often perform selective reduction in monochorionic pregnancies to safeguard the healthier co-twin from acute hemodynamic collapse. A systematic review published in the American Journal of Obstetrics and Gynecology evaluated 22 studies covering 686 gestations. The investigators examined survival rates, delivery timing, and procedural techniques to clarify clinical outcomes.
Selective Reduction in Monochorionic Pregnancies: Overall Risks
The shared placental vasculature poses unique risks during fetal interventions. Overall, the pooled rate of co-twin intrauterine fetal demise reached 15% across all cohorts. Additionally, the rate of co-twin neonatal death was 4%. The average gestational age at birth was 35.4 weeks. Therefore, the procedure provides a substantial chance for the viable co-twin to survive to late preterm or early term gestations.
Comparing Surgical Techniques: BCC Versus RFA
Surgeons frequently use bipolar cord coagulation or radiofrequency ablation. In the primary indirect analysis, pooled co-twin demise appeared higher after radiofrequency ablation than after bipolar coagulation, showing 20% versus 9%. However, when researchers applied generalized linear mixed models, this difference diminished to 14.8% versus 6.6% and lost statistical significance. Furthermore, direct within-study comparisons revealed no statistically significant divergence in co-twin survival between techniques.
Interestingly, patients undergoing bipolar cord coagulation delivered earlier than those treated with radiofrequency ablation. Specifically, median gestational age at birth was 34.5 weeks with coagulation compared to 36.8 weeks with ablation. However, unmeasured baseline confounding likely explains these variations between studies. Because current direct evidence remains limited, existing data do not establish superiority of either surgical approach.
Frequently Asked Questions
Q1: What is the primary goal of selective reduction in monochorionic twin pregnancies complicated by sFGR?
The primary goal is to prevent unexpected intrauterine demise of the severely growth-restricted fetus from causing catastrophic cotwin demise or severe neurological injury through shared placental vascular connections.
Q2: Does radiofrequency ablation provide better co-twin survival than bipolar cord coagulation?
Current evidence does not establish any clear survival advantage for either technique. While indirect analyses showed varied loss rates, adjusted sensitivity models and direct comparisons found no statistically significant difference in co-twin fetal death.
References
- Rojhani E et al. Selective Reduction in Monochorionic Pregnancies With Selective Fetal Growth Restriction: A Systematic Review and Meta-analysis. Am J Obstet Gynecol. 2026 Sep 29. doi: undefined. PMID: 42810704.
- Bebbington MW, Danzer E, Moldenhauer J, et al. Radiofrequency ablation vs bipolar umbilical cord coagulation in the management of complicated monochorionic pregnancies. Ultrasound Obstet Gynecol. 2012;40(3):319-324.
- Bhide A, Khalil A, Arulkumaran 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(2):114-118.
