Complicated Monochorionic Pregnancies Research Articles

SFM Fetal Therapy Practice Guidelines: Fetal Interstitial Laser

AbstractFetal laser therapy was first used in complicated monochorionic pregnancies such as twin-to-twin transfusion syndrome or twin-reversed arterial perfusion sequence. There are some other less common indications such as amniotic band syndrome, chorioangiomas, lower urinary tract obstructions, sacrococcygeal teratomas, and fetal thoracic masses. These practice guidelines discuss the indications, contraindications, and risks of the procedure along with information for patients and draft consent form.

Placental differences between uncomplicated and complicated monochorionic diamniotic pregnancies on diffusion and multicompartment Magnetic Resonance Imaging

IntroductionTwin-twin transfusion syndrome (TTTS) and selective fetal growth restriction (sFGR) are common complications in monochorionic diamniotic (MCDA) pregnancies. The Diffusion-rElaxation Combined Imaging for Detailed Placental Evaluation (DECIDE) model, a placental-specific model, separates the T2 values of the fetal and maternal blood from the background tissue and estimates the fetal blood oxygen saturation. This study investigates diffusion and relaxation differences in uncomplicated MCDA pregnancies and MCDA pregnancies complicated by TTTS and sFGR in mid-pregnancy. MethodsThis prospective monocentric cohort study included uncomplicated MCDA pregnancies and pregnancies complicated by TTTS and sFGR. We performed MRI with conventional diffusion-weighted imaging (DWI) and combined relaxometry – DWI-intravoxel incoherent motion. DECIDE analysis was used to quantify different parameters within the placenta related to the fetal, placental, and maternal compartments. ResultsWe included 99 pregnancies, of which 46 were uncomplicated, 12 were complicated by sFGR and 41 by TTTS. Conventional DWI did not find differences between or within cohorts. On DECIDE imaging, fetoplacental oxygen saturation was significantly lower in the smaller member of sFGR (p = 0.07) and in both members of TTTS (p = 0.01 and p = 0.004) compared to the uncomplicated pairs. Additionally, average T2 relaxation time was significantly lower in the smaller twin of the sFGR (p = 0.004) compared to the uncomplicated twins (p = 0.03). ConclusionMulticompartment functional MRI showed significant differences in several MRI parameters between the placenta of uncomplicated MCDA pregnancies and those complicated by sFGR and TTTS in mid-pregnancy.

Surveillance of pregnancy outcome of monochorionic twins at Tu Du Hospital

Background: Monochorionic twins are a high risk pregnancy and are associated with special complications that are unique to sharing a placenta and because of the hemodynamic imbalance caused by placental vascular anastomoses. Therefore, the outcome of monochorionic twins is still being researched and reported to looking for the best evidence to perform the optimal interventions.
 Objectives: To describe the outcome of monochorionic twins to determine the proportion of special complications. Moreover, exploring the rate of fetal death in uterus, premature delivery, the successful vaginal birth in complicated monochorionic twins after bipolar cord coagulation.
 Materials and Methods: Case series report of monochorionic twins which was managed pregnancy and delivered at Tu Du hospital between January 2018 and January 2019, comprised 166 cases with 81 complicated monochorionic twin pregnancies.
 Results: The series comprised 85 uncomplicated monochorionic twins (51.2%) and 81 complicated cases (48.8%) with 15% twin-twin transfusion syndrome (TTTS) and 28.3% selective intrauterine growth restriction (sIUGR). Nineteen cases of bipolar cord coagulation perfomed included seven TTTS, eight sIUGR, three cases with serious malformation, and one twin reversed arterial perfusion sequence (TRAP).
 Conclusions: TTTS and sIUGR are complications unique to monochorionic twins and diagnosed in the early stage after 23 week’s gestation. Bipolar cord coagulation is an effective procedure in complicated monochorionic pregnancies to improve pregnancy outcome.

Single fetal demise in monochorionic twins: How to predict cerebral injury in the survivor co-twin?

The aims of the study were to evaluate perinatal outcome in monochorionic (MC) twins complicated with single intrauterine fetal death, spontaneously vs after fetal therapy, and to assess antenatal events that increase the risk of cerebral injury. Historical cohort study of MC pregnancies with single intrauterine fetal death diagnosed or referred to a tertiary referral hospital (2012-2020). Adverse perinatal outcome included termination of pregnancy, perinatal death, abnormal fetal or neonatal neuroimaging and abnormal neurological development. A total of 68 MC pregnancies with single intrauterine fetal death after 14 weeks of gestation were included. Sixty-five (95.6%) occurred in complicated MC pregnancies (twin to twin transfusion syndrome: 35/68 [51.5%]; discordant malformation: 13/68 [19.1%], selective intrauterine growth restriction: 10/68 [14.7%], twin reversed arterial perfusion sequence: 5/68 [7.3%] and cord entanglement in monoamniotic twins: 2/68 [2.94%]). In 52 cases (76.5%) single intrauterine fetal demise occurred after fetal therapy and in 16 (23.5%) occurred spontaneously. Cerebral damage included 14/68 cases (20.6%): 6/68 cases (8.82%) were prenatal lesions and 8/68 cases (11.8%) were postnatal. Risk of cerebral damage tended to be higher in the spontaneous death group (6/16, 37.5%) compared to the therapy-group (8/52, 15.38%) (p = 0.07). The risk increased with gestational age at intrauterine death (OR 1.21, 95% CI: 1.04-1.41, p = 0.014) and was higher in those surviving co-twins who developed anemia (OR 9.27, 95% CI: 1.50-57.12, p = 0.016). Pregnancies complicated with selective intrauterine growth restriction tended to be at higher risk for neurological damage (OR 2.85, 95% CI: 0.68-11.85, p = 0.15). Preterm birth rate (<37 weeks of pregnancy) was 61.7% (37/60). Seven of eight postnatal cerebral lesions (87.5%) were related to extreme prematurity. Overall perinatal survival rate was 88.3% (57/68) and 7% (4/57) of children had an abnormal neurological outcome. Risk of cerebral damage in single intrauterine fetal death is especially high when it occurs spontaneously. Gestational age at single intrauterine fetal death, selective intrauterine growth restriction and anemia of the surviving co-twin are the main predictors for prenatal lesions and might be useful in parent counseling. Abnormal postnatal neurological outcome is closely related to extreme prematurity.

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

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). 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. 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. 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. 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.

The Role of Fetal Brain Magnetic Resonance Imaging in Current Fetal Medicine.

In open spina bifida we studied the use of MRI for the assessment of the posterior fossa and prevalence of supratentorial anomalies before and after in utero repair. New postprocessing techniques were applied to evaluate fetal brain development in this population compared to controls. In fetuses with congenital diaphragmatic hernia, we evaluated the brain development in comparison to controls. Diffusion weighted imaging was applied to study difference between fetuses with proven first trimester cytomegalovirus infection and controls. Finally, we investigated the value of third trimester fetal brain MRI after treatment for complicated monochorionic diamniotic pregnancies.

Perinatal and neurodevelopmental outcome in complicated monochorionic pregnancy after selective fetal reduction: radiofrequency ablation vs microwave ablation.

To summarize our experience in the application of radiofrequency ablation (RFA) and microwave ablation (MWA) for selective fetal reduction in complicated monochorionic pregnancies and compare the perinatal outcome of the two techniques. This was a retrospective study of data from a consecutive cohort of all monochorionic twin pregnancies that underwent selective fetal reduction with RFA or MWA at Peking University Third Hospital, Beijing, China from January 2012 to December 2018. All surviving cotwins were followed up to assess their neurodevelopment using the Age &amp; Stage Questionnaire, Chinese version. Perinatal and neurodevelopmental outcomes were compared between the RFA and MWA groups. We also fitted multivariable models to test the association between procedure-related factors and the main perinatal outcomes, including preterm birth (PTB) &lt; 37 weeks' gestation, intrauterine fetal death (IUFD) of the cotwin, adverse outcome (defined as occurrence of IUFD of the cotwin, termination of pregnancy or PTB &lt; 28 weeks) and overall survival. In total, 45 cases (42 twin and three triplet pregnancies) underwent RFA and 126 cases (105 twin and 21 triplet pregnancies) underwent MWA. The overall survival rates in monochorionic diamniotic twin pregnancies were similar between the RFA and MWA groups (61.0% vs 67.0%; P = 0.494). However, pregnancies whose indication for fetal reduction was selective intrauterine growth restriction or twin reversed arterial perfusion had higher overall survival rates (75.5% and 82.6%, respectively) compared with those in other indication groups. A total of 104 children were followed up (20 in the RFA group and 84 in the MWA group); four (20.0%) and eight (9.5%) children were assessed as having overall developmental delay in the RFA and MWA groups, respectively, with no significant difference between the two groups. Multivariable analyses showed that procedure indication, number of ablation cycles and gestational age at procedure were associated significantly with the main perinatal outcomes. RFA and MWA for selective fetal reduction in complicated monochorionic pregnancies can achieve similar overall survival rate and neurodevelopmental outcome, but MWA is associated with a lower risk of preterm birth. Moreover, procedure-related factors are associated significantly with perinatal outcome. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Early detection of ischemic brain injuries by diffusion-weighted imaging after radiofrequency ablation for fetal reduction in monochorionic pregnancies.

This study aimedto investigate the additional advantages of magnetic resonance imaging (MRI), particularly diffusion-weighted imaging (DWI) over fetal ultrasound in the detection of acute ischemic cerebral injuries in complicated monochorionic (MC) pregnancies that underwent selective reduction by radiofrequency ablation (RFA). This prospective cohort study was conducted on 40 women with complicated MC pregnancies who were treated by RFA. Fetal brain imaging by DWI and conventional MRI was performed either in the early (within 10 days after RFA) or late phase (after 3-6 weeks) in the surviving fetuses to detect both acute and chronic ischemic injuries. The presence of anemia after RFA was also evaluated by Doppler ultrasound. Overall, 13 of the total 43 fetuses (30.23%) demonstrated MRI abnormalities with normal brain ultrasound results including germinal matrix hemorrhage (GMH), extensive cerebral ischemia, and mild ventriculomegaly. Although seven fetuses with GMH eventually survived, fetuses that demonstrated ischemic lesions and ventriculomegaly on MRI died in the uterus. The absence of abnormal cerebral lesions or anemia on ultrasound and Doppler exams does not necessarily rule out fetal brain ischemia. Performing early MRI, particularly DWI seems to be a reasonable option for detection of early intracranial ischemic changes and better management of complicated multiple pregnancies which were treated by RFA.

Outcome of Monochorionic Pregnancies after Selective Feticide with Bipolar Cord Coagulation: A German Single Center Experience.

Objectives: To review the outcome of complicated monochorionic pregnancies after fetoscopic selective feticide with bipolar cord coagulation in an experienced German center. Methods: All cases that underwent selective feticide using fetoscopic bipolar umbilical cord occlusion (and simultaneous dissection in monoamniotics) at the University of Bonn in the past 10 years were retrospectively analyzed for antenatal and neonatal course and outcome. An adverse outcome was defined as either intrauterine death (IUD), neonatal death (NND), preterm prelabour rupture of membranes (PPROM), or preterm delivery (PTD) before 32.0 weeks of gestation. Results: We diagnosed 56 monochorionic pregnancies, including 43 diamniotic and 8 monoamniotic twins, as well as 5 triplets, complicated by discordant fetal anomalies (n = 10), selective intrauterine growth restriction (n = 29), twin-to-twin transfusion syndrome (n = 13), twin reversed arterial perfusion sequence (n = 3), or severe early twin anemia polycythemia sequence (n = 1), that underwent fetoscopic selective feticide in the 10 years study period. Selective feticide was performed by bipolar cord coagulation at a median gestational age of 21.2 weeks. PPROM occurred in 11 cases, 7 (12.5%) before 32.0 weeks and 4 (7.1%) between 34.0 and 36.0 weeks, respectively. There were five (8.9%) co-twins IUDs at a median of 2 weeks after the intervention. We observed 12 (21.4%) PTDs before 32.0 weeks of gestation and 2 (3.6%) NNDs. Mean gestational age at delivery was 37.1 weeks, with an overall survival of the co-twin of 87.5%. Conclusion: In experienced hands, fetoscopic selective feticide is an effective treatment in complicated monochorionic pregnancies. By sacrificing a sick fetus that jeopardizes the entire pregnancy, a higher survival rate of the co-twin can be achieved.

Success Rate and Perinatal Outcomes of Selective Reduction by Radiofrequency Ablation in Monochorionic Multiple Pregnancies with a Hydropic Fetus; A Prospective Interventional Single-Arm Study.

Selective reduction of the fetus is one of the therapeutic methods in complicated monochorionic twins. The present study aimed to investigate the success rate and perinatal outcomes of selective reduction using radiofrequency ablation (RFA) in monochorionic multiple pregnancies with a hydropic fetus. This prospective interventional single-arm study was conducted in a referral hospital from 2017 to 2019. Totally, 27 complicated monochorionic twin and triplet pregnancies underwent RFA to occlude the umbilical vein of the hydropic fetus. The participants were followed until 2 months post-delivery. Procedure success rate, survival rate, gestational age at delivery, and neonatal outcome were evaluated. The umbilical cord in 26 (96.2%) cases was successfully occluded by RFA with no maternal complications. Live birth was within 75%. The mean±SD age at delivery was 34.4±3.83 weeks. The gestational age at delivery in TTTS (twin-to-twin transfusion syndrome)-induced hydrops was significantly lower than the non-TTTS hydrops group (P=0.003). Four cases experienced preterm premature rupture of the membranes (PPROM) before 34 weeks. Of all viable neonates, 8 cases were admitted to the neonatal intensive care unit (NICU). In 2 months follow-up post-delivery, all neonates had normal findings without any adverse outcomes. Selective reduction by RFA in complicated monochorionic pregnancies with a hydropic fetus may be a safe method with a high success rate and 100% neonatal survival. This method may be optimal for feticide in non-TTTS hydropic twins.

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

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).

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

BackgroundTo evaluate the perinatal outcomes in women with selective termination using ultrasound-guided radiofrequency ablation (RFA).MethodsComplicated 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.ResultsThree 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).ConclusionsRFA 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.

Perinatal outcomes after selective feticide via umbilical cord occlusion in complicated monochorionic pregnancies: A systematic review and meta‐analysis

We aimed to compare perinatal outcomes between umbilical cord occlusion techniques in monochorionic pregnancies, including umbilical cord ligation, fetoscopic laser coagulation, interstitial laser coagulation, bipolar cord occlusion, radiofrequency ablation, and microwave ablation. This study was registered with PROSPERO (CRD42020158861). PubMed, Web of Science, Cochrane Library, and Embase were searched for studies published up to May 2020. The DerSimonian-Laird random-effects model was used for the meta-analysis. Subgroup analyses were performed to compare the outcomes among the six techniques. Meta-regression was used to adjust for confounders. Thirty-four studies with 1646 participants were included. The overall survival was 76.5% after umbilical cord ligation, 78.8% after fetoscopic laser coagulation, 60.3% after interstitial laser coagulation, 79.2% after bipolar cord occlusion, 77.5% after radiofrequency ablation, and 75.0% after microwave ablation. Subgroup comparison showed the rates of overall survival and preterm premature rupture of membranes were not significant different among six techniques. However, rates of fetal loss, premature birth, live birth, and neonatal death differed significantly among the six groups. The choice of umbilical cord occlusion techniques will affect perinatal outcomes. We suggested that the choice of umbilical cord occlusion techniques should fully consider these differences among techniques.

VP40.02: Perinatal outcomes in complicated monochorionic pregnancies after umbilical cord occlusion: radiofrequency ablation versus microwave ablation

VP40.02: Perinatal outcomes in complicated monochorionic pregnancies after umbilical cord occlusion: radiofrequency ablation versus microwave ablation

Perinatal outcome in monochorionic twin pregnancies after selective fetal reduction using radiofrequency ablation.

To study the perinatal outcomes in women with complicated monochorionic twin pregnancies undergoing selective fetal reduction using radiofrequency ablation (RFA). This retrospective study included 44 patients with monochorionic twin pregnancies, between 14 and 28weeks of pregnancy, who underwent RFA for selective fetal reduction. Perinatal and maternal outcomes and procedure-related complications were analyzed. The procedure was technically successful in all 44 cases. Indications for selective fetal reduction included twin-to-twin transfusion syndrome (52.3%), twin reversed arterial perfusion (20.5%), twins discordant for anomaly (15.9%), and selective fetal growth restriction (11.4%). Median gestational age at procedure was 222/7 weeks (range 14-266/7 ). Live birth rate was 77.3% with three neonatal deaths; so overall survival was 70.5%. Median procedure-to-delivery interval was 123/7 weeks (range 24/7 -23). There were eight losses before 24weeks of pregnancy, which included two co-twin deaths. Median gestational age at delivery was 35weeks (interquartile range 321/7 -37weeks). The preterm delivery rate was 66.7% (24/36) and preterm prelabor rupture of membranes (PPROM) occurred in 22.7% (10/44) of patients. Selective fetal reduction using RFA is safe and effective in complicated monochorionic pregnancies. However, the rates of PPROM and preterm delivery remain high.

Outcome of radiofrequency ablation for selective fetal reduction before vs at or after 16 gestational weeks in complicated monochorionic pregnancy

To investigate whether gestational age at intervention (< or ≥ 16 weeks) and other factors affect the risk of loss of the cotwin after selective fetal reduction using radiofrequency ablation (RFA) in monochorionic (MC) pregnancy. This was a single-center retrospective analysis of 63 consecutive RFA procedures performed at our institution from January 2011 to October 2019 for selective fetal reduction in complicated MC pregnancies. Indications for RFA were twin reversed arterial perfusion sequence (13 cases), twin-to-twin transfusion syndrome (12 cases), twin anemia-polycythemia sequence (two cases), selective fetal growth restriction (10 cases), discordant anomalies (17 cases) and multifetal pregnancy reduction in triplets or quadruplets with a MC pair (nine cases). Twenty-six (41.3%) of these procedures were performed before and 37 (58.7%) after 16 weeks. Potential factors that could affect the risk of loss of the cotwin, including gestational age at RFA, order of multiple pregnancy, amnionicity, indication for RFA and number of ablation cycles, were assessed first by univariate analysis and then by multivariate analysis. There were 17 (27.0%) cotwin losses. Ablation cycles numbering four or more was the only factor among those investigated to be associated with loss of the cotwin after RFA (P = 0.035; odds ratio, 5.21), while the indication for RFA, order of multiple pregnancy, amnionicity and gestational age at RFA had no effect. Comparing RFA performed at < 16 vs ≥ 16 weeks, there was no difference in the rate of cotwin loss (23.1% vs 29.7%; P = 0.558) or preterm prelabor rupture of the membranes before 34 weeks (7.7% vs 5.4%; P = 0.853), or in the median gestational age at delivery (36.2 vs 37.3 weeks; P = 0.706). RFA is a promising tool for early selective fetal reduction in MC pregnancy before 16 weeks. Four or more ablation cycles is a major risk factor for cotwin loss. Careful assessment pre- and post-RFA, together with proficient operative skills to minimize the number of ablation cycles, are the mainstay to ensure that this procedure is effective and safe. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Call to action: long‐term neurodevelopment in monochorionic twins

Call to action: long‐term neurodevelopment in monochorionic twins

Ultrasound findings in Pseudoamniotic band syndrome after fetoscopic surgery: Antenatal description of three cases and review of literature

IntroductionPseudoamniotic Bands Syndrome (PABS) was described as iatrogenic complication from in utero procedure as fetoscopy. ObjectiveThe aim of our study was to identify the ultrasound findings in PABS diagnosed prenatally MethodsFirst, we reported cases of PABS following fetoscopic surgery that were diagnosed prenatally in our institution. We collected all ultrasound data with fetal and neonatal issues. Then, a literature review was conducted by searching the Medline and Cochrane Library computer databases until 2020 to find publications that involve PABS diagnosed prenatally or postnatally. The following keywords were selected and combined: “pseudoamniotic bands syndrome”, “fetoscopy”, “fetal surgery”. ResultsWe collected three cases of PABS diagnosed prenatally in our center following fetoscopic procedures for complicated monochorionic pregnancies. Among these cases, we reported the following ultrasound findings: floating membrane, amniotic bands, striction of limbs, perilesional edema, reduced member size and anomalies of Doppler flow. Including our cases, we reported 23 published PABS of which eight (35%) were prenatally diagnosed. When it was diagnosed, mean GA at PABS diagnosis was 23 weeks (mean interval from fetoscopic to diagnosis was 4 weeks). Three fetoscopic release of amniotic bands were described. The principal parts affected were the limbs, more particularly the extremities. ConclusionPABS was accessible to an antenatal diagnosis, as well as ABS. Although it is a rare complication of fetoscopic surgery, ultrasound examinations after procedure should focus on PABS signs to improve prognosis of the neonates.

Influence of indications on perinatal outcomes after radio frequency ablation in complicated monochorionic pregnancies: a retrospective cohort study

BackgroundRadiofrequency ablation (RFA) is recommended to prevent potential neurological injury or intrauterine foetal death (IUFD) of the co-twin(s) in complicated monochorionic (MC) pregnancies. However, the impacts of various indications on the pregnancy outcome following RFA remain unclear. This study aimed to determine how the indications influence the perinatal outcomes in complicated MC pregnancies undergoing radiofrequency ablation.MethodsThis was a retrospective cohort study performed in a single centre. All consecutive MC pregnancies treated with RFA between July 2011 and July 2019 were included. The adverse perinatal outcomes and the survival rate were analysed based on various indications. The continuous variables with and without normal distribution were compared between the groups using Student’s t-test and Mann–Whitney U test, respectively, and for categorical variables, Chi-square and Fisher’s exact tests were used. P < 0.05 indicated a significant difference.ResultsWe performed 272 RFA procedures in 268 complicated MC pregnancies, including 60 selective intrauterine growth restriction (sIUGR), 64 twin–twin transfusion syndrome (TTTS), 12 twin reversed arterial perfusion sequence (TRAPs), 66 foetal anomaly and 66 elective foetal reduction (EFR) cases. The overall survival rate of the co-twin was 201/272 (73.9%). The overall technical successful rate was determined at 201/263 (76.7%). The IUFD rate in the co-twin was 20/272 (7.4%). The TTTS group had recorded the lowest survival rate (37/64, 57. 8%), and the survival rate was significantly correlated with Quintero stages (P = 0.029). Moreover, the sIUGR III subgroup had a lower survival rate compared with sIUGR II (55.6%, versus 84.3%). The subgroup of foetal anomaly of gastroschisis or exomphalos had the highest IUFD rate (4/10, 40%), followed by sIUGR III (2/9, 22.2%) and dichorionic triamniotic (DCTA) subgroup (8/46, 17.9%). In EFR group, eight IUFD cases were all coming from the DCTA subgroup and received RFA before 17 weeks.ConclusionsThe perinatal outcome of RFA was correlated with the indications, with the lowest survival rate in TTTS IV and the highest IUFD incidence in abdominal wall defect followed by sIUGR III. Elective RFA after 17 weeks may prevent IUFD in DCTA pregnancies.

VP22.11: Outcomes of radiofrequency ablation for selective fetal reduction in complicated monochorionic pregnancies performed before or after 16 gestational weeks

VP22.11: Outcomes of radiofrequency ablation for selective fetal reduction in complicated monochorionic pregnancies performed before or after 16 gestational weeks