Risk Factors for Co-Twin Fetal Demise following Radiofrequency Ablation in Multifetal Monochorionic Gestations

Predictors of dual demise within the first week after selective cord occlusion via radiofrequency ablation for complex monochorionic pregnancies

BACKGROUND

Selective cord occlusion is an option in complicated monochorionic multiple gestations with the goal of reducing the pregnancy by one fetus and to optimize the outcomes for the remaining fetus(es).

OBJECTIVE

This study aimed to determine the rate and associated risk factors of dual demise in complex monochorionic pregnancies after selective cord occlusion via radiofrequency ablation.

STUDY DESIGN

This was a single-center analysis of a prospective registry cohort of complex monochorionic pregnancies managed with selective cord occlusion via radiofrequency ablation between 2014 and 2021. A total of 167 pregnancies met the inclusion criteria and were evaluated on the basis of the intended outcome of dual demise vs singleton survival. Risk factors were compared between the 2 groups. The Mann-Whitney U test was used for continuous variables and the Fisher exact test was used for categorical variables.

RESULTS

The incidence of postprocedure dual demise within the first week after performing radiofrequency ablation was 10.8% (18/167). The risk was higher in pregnancies undergoing radiofrequency ablation for discordant anomaly, and this subcategory constituted 38.9% of pregnancies in the dual demise subgroup (P=.02). Lower intertwin estimated fetal weight discordance (P=.01) was associated with dual demise. Perioperative variables including gestational age at procedure, placental cord insertion distance, operative time, and radiofrequency ablation time were similar in those with and without dual demise.

CONCLUSION

Our results show that selective cord occlusion via radiofrequency ablation is a safe and reasonable option in complicated monochorionic pregnancies, with low rates of dual demise within the first week after the procedure.

Co-twin survival after selective fetal reduction in complicated multiple gestations: A systematic review and meta-analysis of survival rate according to indication for intervention

OBJECTIVE

Determine the impact of indication for selective reduction (SR) on co-twin survival in monochorionic gestations undergoing radiofrequency ablation (RFA) or bipolar cord coagulation (BCC).

METHODS

PubMed and Web of Science were systematically searched from inception of databases to April 2021. Frequency of indications was compared between post-intervention co-twin survival and demise groups undergoing SR. Random-effect model was used to pool mean differences or odds ratios (OR) and corresponding 95% confidence intervals (CIs). Heterogeneity was assessed using the I² value.

RESULTS

Of 1060 studies assessed for eligibility, nine studies met criteria. A total of 666 pregnancies underwent RFA (n = 483 co-twin survival) and 235 pregnancies underwent BCC (n = 188 co-twin survival). Twin twin transfusion syndrome (TTTS), as an indication for RFA, was associated with decreased co-twin survival (OR 0.61, 95% CI 0.41, 0.90, P 0.01, I² 0.0%). Other indications for RFA were not associated with significant difference in co-twin survival. With BCC, none of the indications were found to significantly influence the co-twin survival following intervention.

CONCLUSION

RFA was found to have lower co-twin survival when performed for TTTS. No other indications was associated with differences in co-twin survival. BCC was not associated with any differences in co-twin survival based on indication.

Fetal reduction for everyone?

Infertility treatments have benefited millions of couples to have their own children; however, the complication of multiple pregnancies with their increased morbidity and mortality has created significant problems. Fetal reduction (FR) was developed to ameliorate these issues. Over 30 years of publications show that FR has been highly successful in substantially reducing both mortality and morbidity. As with most radically new techniques, initial cases were in the "nothing to lose" category. With experience, indications liberalize, and quality of life issues increase as a proportion of cases. Overall risks for twins are not twice as those for singletons, but they are approximately 4- to 5-fold higher. In experienced hands, the combination of genetic testing by CVS followed by FR has made most multiples behave statistically as if they were originally the lower number. The use of microarray analysis to better determine fetal genetic health before deciding on which fetus(es) to keep or reduce further improves pediatric outcomes. With increasing experience and lower average starting numbers, the proportion of FRs to a singleton has increased considerably. Twins to a singleton FR now constitute an increasing proportion of cases performed. Data on such cases show improved outcomes, and we believe FR should be at least discussed and offered to all patients with a dichorionic twin pregnancy or higher. eSET is not a panacea because of the resultant monochorionic twins.

Fetal reduction and twins

Infertility treatments have allowed millions of couples to have their own children, but resultant multiple pregnancies with their increased morbidity and mortality have been a significant complication. Fetal reduction was developed to ameliorate this issue. Over 30 years of publications show that fetal reduction has been highly successful in substantially reducing both mortality and morbidity related to multiple pregnancies. As with most radically new techniques, initial cases were in the "nothing to lose" category. With experience, indications liberalize, and quality of life issues gain relevance. The overall risks of twin pregnancy are not twice that of singleton pregnancy; they are about 4 to 5 times higher. In experienced hands, the combination of genetic testing by chorionic villus sampling followed by fetal reduction has made the outcomes of most multiple pregnancies statistically equivalent to those of pregnancies with lower fetal numbers. Use of microarray analysis to better determine fetal genetic health before deciding on which fetus(es) to keep or reduce further improves pediatric outcomes. With increasing experience and lower average starting numbers, the proportion of fetal reductions to a singleton has increased considerably. Twins to a singleton fetal reductions now constitute an increasing proportion of cases performed. Data on such cases show improved outcomes, and we believe fetal reduction should be at least discussed and offered to all patients with a dichorionic twin pregnancy or higher. With the increasing reliance on elective single-embryo transfers, monochorionic twins, which have much higher complication rates than dichorionic twins, have increased substantially. Furthermore, monochorionic twins cannot be readily and safely reduced, so the adverse perinatal statistics of elective single-embryo transfer are a major setback for good outcomes. Although elective single-embryo transfer is appropriate for some, we believe that for many couples, the transfer of 2 embryos is generally a more rational approach.

Selective termination of the fetus in multiple pregnancies using ultrasound-guided radiofrequency ablation

Background

To evaluate the perinatal outcomes in women with selective termination using ultrasound-guided radiofrequency ablation (RFA).

Methods

Complicated monochorionic (MC) twin pregnancies and multiple pregnancies with an indication for selective termination by ultrasound-guided coagulation of the umbilical cord with RFA under local anesthesia between July 2013 and Jan 2020 were reviewed. We analyzed the indications, gestational age at the time of the procedure, cycles of RFA, duration of the procedure, and perinatal outcome.

Results

Three hundred and thirteen patients were treated during this period. Seven of whom were lost of follow-up. The remaining 306 cases, including 266 pairs of monochorionic diamniotic (MCDA) twins (86.93%), two pairs of monoamniotic twins (0.65%), 30 dichorionic triamniotic (DCTA) triplets (1%), and three monochorionic triamniotic (MCTA) triplets (0.98%), were analyzed. Indications included twin-to-twin transfusion syndrome (TTTS) (n = 91), selective fetal growth restriction (sFGR) (n = 83), severe discordant structural malformation (n = 78), multifetal pregnancy reduction (MFPR) (n = 78), twin reverse arterial perfusion sequence (TRAPS) (n = 19), and twin anemia-polycythemia sequence (TAPS) (n = 3). Upon comparison of RFA performed before and after 20 weeks, the co-twin loss rate (20.9% vs. 21.5%), the incidence of preterm premature rupture of membranes (PPROM) within 24 h (1.5% vs. 1.2%), and the median gestational age at delivery [35.93 (28–38) weeks vs. 36 (28.54–38.14) weeks] were similar (p > 0.05).

Conclusions

RFA is a reasonable option when indicated in multiple pregnancies and complicated monochorionic pregnancies. In our experience, the overall survival rate was 78.76% with RFA in selective feticide, and early treatment increases the likelihood of survival for the remaining fetus because the fetal loss rate is similar before and after 20 weeks.