Selective reduction in complicated monochorionic pregnancies: radiofrequency ablation vs. bipolar cord coagulation

Clinical outcomes of fetal selective reduction in dichorionic triplet pregnancies

BACKGROUND

It is recommended to reduce triplet pregnancy containing monochorionic (MC) twins to singleton. Given that some couples with infertility are eager to retain twins, better strategy is needed to avoid obstetrical risks and satisfy their strong wish. This retrospective observational study aimed to investigate the outcomes of triplet pregnancy reduction.

METHODS

Subjects with triplet pregnancies who underwent selective reduction between 2016 and 2019 at our hospital were enrolled. A total of 66 subjects with dichorionic triplet (DCT) with MC twins and an MC singleton were divided into two groups: group A (N = 38), reduced to dichorionic diamniotic (DCDA) twins; group B (N = 28), reduced to MC diamniotic (MCDA) twins. Obstetrical and perinatal outcomes were compared between groups.

RESULTS

Group A had significantly lower rates of early miscarriage (0% vs 14.3%, p = 0.028), cesarean section (81.6% vs 100%, p = 0.041), and late premature delivery (21.1% vs 45.4%, p = 0.047) than group B. Significantly higher rates of full-term delivery (71% vs 36.4%, p = 0.009) and take-home baby (100% vs 78.6%, p = 0.004), and higher gestational age at delivery (median: 38 [36.9, 39.0] vs 35.8 [34.4, 37.0] weeks, p < 0.001), total neonatal weight (2899.7 ± 647.6 vs 2354.4 ± 651.8 g, p < 0.001), weight of twins (2550 vs 2350 g, p = 0.039), and weight of larger neonate in twins (2790 vs 2500 g, p = 0.045) were observed in group A compared to group B.

CONCLUSION

DCT reduced to DCDA twins confers better pregnancy outcomes than into MCDA twins. This might benefit for triplet pregnancy subjects who strongly want to retain fraternal twins.

Structural Anomalies in Multifetal Gestations

Multifetal gestations are at increased risk for structural anomalies relative to singletons. Determination of chorionicity is critical, as the risk is highest for monochorionic pregnancies. In a singleton gestation, counseling is structured around optimization of fetal outcomes and careful consideration of the patient's choices in management decisions. However, in multifetal gestations affected by a fetal anomaly, complex counseling with consideration for the pregnancy as a whole is necessary. We review the incidence of structural anomalies in twins and highlight unique considerations including selective termination for discordant anomalies. We emphasize the role of shared decision making between provider and patient.

Monochorionic twins with discordant trisomy 21, another case to remind this uncommon condition and how to deal with

Monozygotic twins discordant for trisomy 21 are rare. We present the twelfth reported case of this uncommon condition undergoing invasive prenatal diagnosis. Dealing with discordant fetal anomalies in monochorionic pregnancy can be challenging for physicians and patients; pros and cons of different invasive procedure options must be discussed with the couple, contending with certain specific peculiarities of this type of pregnancy. Although chorionic villi sampling can be performed earlier, higher risk of misdiagnosis of discordant aneuploidy is reported. Indeed, when heterokaryotic twins are suspected, a two-sampling amniocentesis is recommended, to ensure independent sampling of each fetus and to rule out confined placental mosaicism as well. The couple should be informed of the possible management and the risks for the non-affected twin whether selective reduction is required, and likewise if the pregnancy continues without selective termination.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

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.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Fetoscopic Laser Ablation for the Selective Fetal Reduction in Twin-Twin Transfusion Syndrome Stage II-IV: The Experience of a New Fetal Medicine Center

Objective

To evaluate the surgery outcomes of fetoscopic laser ablation (FLA) for selective umbilical cord in treating twin-twin transfusion syndrome (TTTS) with special conditions and neonatal outcomes post-operation.

Methods

A prospective study, 21 monochorionic diamniotic (MCDA) twins diagnosed with TTTS stage II–IV according to Quintero classification from 16 to 26 weeks of gestation, among that, 12 cases of TTTS stage II with selective intrauterine growth restriction (sIUGR), 6 cases of TTTS stage II with proximate cord insertions, 3 cases of TTTS stage IV underwent fetoscopic laser ablation for the selective fetal reduction at Hanoi Obstetrics and Gynecology Hospital from September 2019 to July 2021. Complications and surgical outcomes were noted. Prenatal care was carried out every 2 weeks post operation until birth. Newborn neurologic complications were assessed at birth, three months, and six months after birth using Denver II test and magnetic resonance imaging (MRI).

Results

The mean gestational age at operation was 20.30 weeks. The average operation duration was 39.52 minutes. No complications of operation, such as bleeding or infection, were recorded. The mean gestational age at birth was 34.70 ± 4.33 weeks, with a mean duration of 12.97 ± 6.87 weeks between intervention and delivery. The survival rate of newborns after the operation was 90.48%. There were two stillbirths (9.52%) within seven days after the operation. No short-term neurological complications have been reported with follow-up of the newborn to 6 months after birth.

Conclusion

Our study showed that fetoscopic laser ablation of selected fetal reduction surgery for treatment of special conditions of TTTS had no complications of operation, high neonatal survival result (90.48%), no short-term neurological complications. This should be considered for TTTS in cases of indication.

Twin reverse arterial perfusion: Timing of intervention

Twin reverse arterial perfusion (TRAP) sequence is a severe anomaly in monochorionic twins where one twin has profound corporeal underdevelopment and acardia. The normal "pump" co-twin provides blood flow to the acardiac twin through placental anastomoses which may lead to cardiac failure and pump twin demise as well as preterm delivery from severe polyhydramnios. Treatments include radiofrequency ablation, bipolar cord coagulation, and intrafetal laser with each aimed at occluding blood flow to the acardiac twin. However, none of these modalities has proven superior in terms of either pump twin survival or minimization of complications, including preterm premature rupture of membranes, preterm birth, or unexpected co-twin demise. The optimal timing of treatment is also unknown, without clear indications for intervention versus expectant management. Very early treatment of TRAP (i.e., <16 weeks) has been proposed to reduce first-trimester demise; however, this approach remains experimental. Further investigation is required to determine the best treatment and timing of intervention for TRAP.

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.

Prediction of post-laser fetal death in selective growth restriction complicating twin-twin transfusion syndrome using standardized definitions

OBJECTIVE

Selective fetal growth restriction (sFGR) complicating twin-twin transfusion syndrome (TTTS) is associated with a 3-6-fold increased risk of fetal demise after fetoscopic laser surgery (FLS). Identifying these patients is challenging due to varying definitions of sFGR used in the literature. The objective of this study was to determine the association of three currently used definitions for sFGR with demise of the smaller twin, typically the donor, following FLS for TTTS.

METHODS

This was a retrospective cohort study of monochorionic diamniotic twin pregnancies undergoing FLS for TTTS between January 2015 and December 2018. Classification of the cohort as sFGR or non-sFGR was performed using three different definitions: (1) estimated fetal weight (EFW) of one twin < 10^th centile and intertwin EFW discordance > 25%, according to the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) (Definition A); (2) EFW of one twin < 3^rd centile, according to the solitary criterion for sFGR reported in a Delphi consensus (Definition B); and (3) presence of at least two of four of the following criteria: EFW of one twin < 10^th centile, abdominal circumference of one twin < 10^th centile, intertwin EFW discordance of ≥ 25% and umbilical artery pulsatility index of the smaller twin > 95^th centile, according to the contributory criteria for sFGR in monochorionic diamniotic twin pregnancies reported in the Delphi consensus (Definition C). Pearson's χ² and univariate and multivariate logistic regression analyses were performed to assess the association of classification as sFGR according to the different definitions with fetal demise within 48 h after FLS.

RESULTS

A total of 124 pregnancies underwent FLS for TTTS during the study period. Of these, 46/124 (37.1%) were identified as having sFGR according to the ISUOG criteria (Definition A), 57/124 (46.0%) based on EFW < 3^rd centile (Definition B) and 70/124 (56.5%) according to the Delphi contributory criteria (Definition C). There were no differences in maternal body mass index, recipient twin amniotic fluid volume, gestational age (GA) at intervention or GA at delivery between sFGR and non-sFGR cases for any of the three definitions. There were also no differences in the rates of postprocedure recipient demise or Doppler abnormalities in the recipient. Regardless of the definition used, sFGR cases showed a significantly higher rate of postprocedure donor twin demise compared with that in non-sFGR cases (Definition A: 28.3% vs 3.8%, P < 0.01; Definition B: 22.8% vs 4.5%, P = 0.02; Definition C: 22.9% vs 0%, P < 0.01). For all of the sFGR definitions, the rate of Stage-III TTTS was increased in sFGR compared to non-sFGR cases (Definition A: 65.2% vs 35.9%, P ≤ 0.01; Definition B: 59.6% vs 35.8%, P = 0.04; Definition C: 62.9% vs 25.9%, P < 0.01). All cases of donor demise met the criteria for sFGR according to Definition C. Classification as sFGR according to Definition C was associated with a significantly higher rate of post-FLS donor demise compared to Definitions A and B (χ² , 15.32; P < 0.01). Logistic regression analysis demonstrated that sFGR cases had an increased risk of donor demise (Definition A: odds ratio (OR), 4.97 (95% CI, 1.77-13.94), P < 0.01; Definition B: OR, 4.39 (95% CI, 1.36-14.15), P = 0.01) and that staging of TTTS was also predictive of demise (OR, 2.26 (95% CI, 1.14-4.47), P = 0.02). After adjusting for GA at intervention and stage of TTTS, the results were similar (Definition A: OR, 6.48 (95% CI, 2.11-24.56), P = 0.002; Definition B: OR, 4.16 (95% CI, 1.35-15.74), P = 0.02).

CONCLUSIONS

The rate of fetal demise following FLS for TTTS is increased in the presence of sFGR. Improving diagnosis of sFGR should improve counseling and may affect management. The Delphi method of defining sFGR based on the presence of at least two of four contributory criteria had the highest predictive value for donor demise following FLS for TTTS. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Twin twin transfusion syndrome with and without selective fetal growth restriction: Predictors of donor demise

OBJECTIVE

Evaluate survival in twin twin transfusion syndrome (TTTS) with and without selective fetal growth restriction (sFGR) after fetoscopic laser surgery (FLS).

METHODS

Retrospective study of monochorionic diamniotic twins undergoing FLS. The cohort was classified as TTTS and TTTS with sFGR. Baseline, intra-operative and postoperative variables were analyzed. Mann-Whitney U, Pearson chi-square, Fisher's exact, t-test and receiver operating characteristic (ROC) curve analysis were performed.

RESULTS

Four hundred and ninety-two pregnancies were included, 304 (61.78%) TTTS and 188 (38.22%) TTTS with sFGR. No difference in donor outcomes. TTTS group had higher donor estimated fetal weight (EFW%) percentile (19.7 ± 18.8 vs. 2.2 ± 2.1, p < 0.001). Significant predictors for demise at 30 days were 37% intertwin weight discordance (IWD) with donor EFW% < first (area under ROC curve [AUC] = 0.85, p = 0.001) or IWD >25% and intertwin umbilical artery pulsatility index discordance (DUAPI) ≥0.4 (AUC = 0.71, p = 0.001).

CONCLUSION

Combination of IWD of 37% and donor EFW% <first was most predictive for demise 30 days after birth. DUAPI ≥0.4 was also associated with increased risk for demise.

Controversies in the management of twin pregnancy

Despite many advances in antenatal care, twin pregnancies still experience more adverse outcomes, in particular perinatal morbidity and mortality. They also pose a multitude of challenges and controversies, as outlined in this Review. Moreover, they are less likely to be included in clinical trials. Many issues on classification and management remain under debate. Efforts at standardizing diagnostic criteria, monitoring protocols, management and outcome reporting are likely to reduce their perinatal risks. The top 10 most important research uncertainties related to multiple pregnancies have been identified by both clinicians and patients. More robust research in the form of randomized trials and large well-conducted prospective cohort studies is needed to address these controversies. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

A cohort study of the perinatal outcome of radiofrequency ablation in complicated monochorionic multiple pregnancies based on a different needle insert angle

OBJECTIVE

To compare the pregnancy outcomes of radiofrequency ablation (RFA) for complicated multiple pregnancies between fetal abdominal and dorsal needle insertion angles.

METHODS

We performed a historical cohort study of patients who underwent selective reduction using RFA through different needle insertion angles from 2015 to 2018 at a local hospital. Dorsal needle insertion cases were consecutively selected and abdominal needle insertion cases were selectively enrolled. The Cox proportional hazards model was constructed to identify predictors of fetal survival time with different needle insertion angles.

RESULTS

The RFA procedure was performed in 28 women through an abdominal insertion angle and in 28 women through a dorsal insertion angle. There were no significant differences in perinatal outcomes between the two groups. The overall live birth rate after RFA in the two groups was 73.5% and the mean gestation was 31.6 ± 6.5 weeks. The Cox model showed that gestational age at RFA was a predictor of the duration of the period between RFA and delivery.

CONCLUSION

RFA conducted through the dorsal insertion angle is technically feasible for selective reduction in complex monochorionic multiple pregnancies. Gestational age at this procedure is an independent risk factor for the duration of pregnancy post-RFA.

Placental Anatomy and Function in Twin Gestations

With an increasing incidence of twin gestations, understanding the inherent risks associated with these pregnancies is essential in modern obstetrics. The unique differences in placentation in twins contribute to the increased risks. Monochorionic twins are susceptible to complications because of their unique placental architecture, including twin-to-twin transfusion syndrome, the twin anemia-polycythemia sequence, selective intrauterine growth restriction, and the twin reversed arterial perfusion sequence. Knowing the clinical correlations of placental anatomy in these gestations helps perinatal pathologists perform a more informed placental evaluation, allowing for better care for the mother and her children.

Selective fetal reduction in complicated monochorionic twin pregnancies: A comparison of techniques

OBJECTIVE

To compare perinatal outcomes associated with three methods of selective reduction in complicated monochorionic (MC) twin pregnancies: bipolar cord coagulation (BC), fetoscopic or ultrasound guided laser cord occlusion and radiofrequency ablation (RFA).

METHODS

Retrospective cohort study of complicated MC twin pregnancies undergoing selective fetal reduction at a tertiary fetal center over a 20-year period. Obstetric and perinatal outcomes were compared.

RESULTS

105 procedures met inclusion criteria: 74 RFAs, 17 lasers and 14 BCs. Procedure duration was significantly shorter for RFA (27.4 ± 15.8 minutes) compared to BC (91.7 ± 38.7 minutes) and laser (83.4 ± 40.4 minutes), P < .0001). The incidence of preterm prelabor rupture of membranes (PPROM) and co-twin demise did not differ between groups, however preterm delivery <34 weeks occurred less frequently following RFA (29.7%), compared to laser (64.7%) or BC (42.9%) (P = .02); delivery <37 weeks was also less frequent following RFA (45.9%), compared to laser (76.5%) or BC (78.6%)(P = .01). The difference in preterm birth<34 weeks between RFA and laser was maintained after adjusting for cord occlusion indication and amnionicity (OR 3.96, 95% CI 1.27-12.31).

CONCLUSIONS

In our experience, RFA procedures were simpler, faster and associated with a lower risk of preterm delivery <34 and <37 weeks, compared to laser or BC.

Reduction of multiple pregnancy: Counselling and techniques

The incidence of multiple births has risen in the last few decades. This rise is mainly due to the widespread use of assisted reproduction techniques mainly as a result of increasing maternal age at conception. Twin and higher-order multiple pregnancies are associated with increased risk of perinatal, as well as maternal, mortality and morbidity compared to singleton pregnancies. There can also be psychosocial and socioeconomic implications for women and their families. In this chapter, we aim to discuss the risks associated with multiple pregnancies, the pros and cons of fetal reduction, the current techniques used in clinical practice, and how to approach counselling parents, enabling them to make informed decisions.

Perinatal outcomes of monochorionic diamniotic triplet pregnancies: a case series

Background

Triplet pregnancies are associated with higher fetal morbidity and mortality rates as well as life-threatening maternal complications. Monochorionic diamniotic (MCDA) triplet pregnancies are very rare compared to other types of triplet pregnancies.

Case presentation

We report three cases of MCDA triplet pregnancies between January 2012 and December 2017. Two of these MCDA triplet pregnancies received regular and intensive prenatal care, were diagnosed by ultrasonography during the first trimester or early second trimester, and had good perinatal outcomes. The case with irregular perinatal care had poor outcomes, and the MCDA triplet pregnancy was diagnosed intrapartum.

Conclusions

The possibility of continuing an MCDA triplet pregnancy should be recognized. Early diagnosis, regular antenatal care, close prenatal monitoring, and sufficient communication are recommended to obtain better perinatal outcomes in MCDA triplet pregnancies.

Complex multigestational anomalies

The increase in multiple gestation pregnancies has resulted in significant health care implications for both mother and child. Our ability to diagnose and intervene on an at-risk multi-gestation pregnancy has dramatically improved. It is important for the pediatric surgeon to be equipped with a basic fund of knowledge concerning these pregnancies. An understanding of amnionicity and chorionicity will equip the practitioner with the ability to identify which pregnancies are at risk for specific complications. This article highlights multi-gestation pregnancies that are monochorionic (single shared placenta) and can be complicated by twin-twin transfusion syndrome (TTTS), twin reversed arterial perfusion (TRAP) sequence, twin anemia polycythemia sequence (TAPS), or selective fetal intrauterine growth restriction (sIUGR). The risk of fetal demise is significant in these pregnancies. Understanding recommended surveillance and warning signs can alert surgeons to developing complications. Specialized fetal care centers possess the ability to intervene on these pregnancies in utero.

Maternal complications following open and fetoscopic fetal surgery: A systematic review and meta-analysis

OBJECTIVE

To establish maternal complication rates for fetoscopic or open fetal surgery.

METHODS

We conducted a systematic literature review for studies of fetoscopic or open fetal surgery performed since 1990, recording maternal complications during fetal surgery, the remainder of pregnancy, delivery, and after the index pregnancy.

RESULTS

One hundred sixty-six studies were included, reporting outcomes for open fetal (n = 1193 patients) and fetoscopic surgery (n = 9403 patients). No maternal deaths were reported. The risk of any maternal complication in the index pregnancy was 20.9% (95%CI, 15.22-27.13) for open fetal and 6.2% (95%CI, 4.93-7.49) for fetoscopic surgery. For severe maternal complications (grades III to V Clavien-Dindo classification of surgical complications), the risk was 4.5% (95% CI 3.24-5.98) for open fetal and 1.7% (95% CI, 1.19-2.20) for fetoscopic surgery. In subsequent pregnancies, open fetal surgery increased the risk of preterm birth but not uterine dehiscence or rupture. Nearly one quarter of reviewed studies (n = 175, 23.3%) was excluded for failing to report the presence or absence of maternal complications.

CONCLUSIONS

Maternal complications occur in 6.2% fetoscopic and 20.9% open fetal surgeries, with serious maternal complications in 1.7% fetoscopic and 4.5% open procedures. Reporting of maternal complications is variable. To properly quantify maternal risks, outcomes should be reported consistently across all fetal surgery studies.

Perinatal outcomes of single fetal survivor after fetal intervention for complicated monochorionic twins

OBJECTIVE

To compare perinatal outcomes between acute single fetal demise following fetoscopic laser photocoagulation to planned selective reduction (SR) in complicated monochorionic twin pregnancies.

METHODS

This was a secondary analysis of prospectively collected data in complicated monochorionic twin pregnancies from 2 fetal centers from 2011 to 2016. Group 1 included women undergoing fetoscopic laser photocoagulation for twin-twin transfusion syndrome (TTTS) who experienced a single fetal demise within 24 hours of the procedure. Group 2 consisted of women undergoing planned selective reduction (SR) with TTTS, and Group 3 SR for indications other than TTTS.

RESULTS

Survival of the remaining co-twin at birth was highest in Group 1 (n = 77 patients; 95%) compared with that in Group 2 (n = 15; 80%) and Group 3 (n = 32; 78%; P = .047). The preterm premature rupture of membrane rate was higher in Group 1 (47%) compared with that in Group 2 (33%) and Group 3 (7%; P < .001). Group 1 had a lower gestational age at delivery and shorter procedure-to-delivery interval compared with the other 2 groups (P < .01).

CONCLUSION

When single fetal demise occurs following fetoscopic laser photocoagulation, the surviving co-twin is more likely to survive to delivery but has higher PPROM rates and a shorter latency period compared with planned selective reduction for TTTS or other indications.

Aplasia cutis congenita as a result of interstitial laser therapy for fetal reduction in monochorionic twins: Conservative approach and outcome

•

Laser therapy for fetal reduction could be associate with Aplasia Cutis Congenita.

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Despite of size of lesion conservative treatment could be an effective option.

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Extreme prematurity did not affected degree of spontaneous epithelization.

•

Patient was followed up to 5 years and no complications were detected.

Monochorionic (MC) twin pregnancies are known to carry a high risk of twin-to-twin transfusion syndrome (TTTS) that could lead to miscarriage and perinatal death. Demise of one fetus is frequently associated with co-fetal death. Fetal reduction by interstitial laser therapy is an effective procedure to prevent this outcome, but it may be associated with significant risks for both mother and fetus. Aplasia Cutis Congenita (ACC) may occur in up to 8% cases of fetal reduction by laser therapy. We report ACC in a preterm infant, a survivor of interstitial laser therapy for fetal reduction in MC pregnancy. Despite of massive skin lesions we were able to manage this case conservatively. Follow-up at 5 years of age revealed minimal scarring and no motor function limitations.

Rapid initiation of fetal therapy services with a system of learner-centred training under proctorship: the National University Hospital (Singapore) experience

INTRODUCTION

Management of complicated monochorionic twins and certain intrauterine structural anomalies is a pressing challenge in communities that still lack advanced fetal therapy. We describe our efforts to rapidly initiate selective feticide using radiofrequency ablation (RFA) and selective fetoscopic laser photocoagulation (SFLP) for twin-to-twin transfusion syndrome (TTTS), and present the latter as a potential model for aspiring fetal therapy units.

METHODS

Five pregnancies with fetal complications were identified for RFA. Three pregnancies with Stage II TTTS were selected for SFLP. While RFA techniques utilising ultrasonography skills were quickly mastered, SFLP required stepwise technical learning with an overseas-based proctor, who provided real-time hands-off supervision.

RESULTS

All co-twins were live-born following selective feticide; one singleton pregnancy was lost. Fetoscopy techniques were learned in a stepwise manner and procedures were performed by a novice team of surgeons under proctorship. Dichorionisation was completed in only one patient. Five of six twins were live-born near term. One pregnancy developed twin anaemia-polycythaemia sequence, while another was complicated by co-twin demise.

DISCUSSION

Proctor-supervised directed learning facilitated the rapid provision of basic fetal therapy services by our unit. While traditional apprenticeship is important for building individual expertise, this system is complementary and may benefit other small units committed to providing these services.

A new method for selective reduction in TRAP sequence with a contraindication to fetoscopic surgery: A case report

RATIONALE

The preferred method for multifetal pregnancy reduction (MFPR) is a transabdominal intrathoracic or intracranial injection of potassium chloride (KCl). However, in monochorionic multiple pregnancies (MMPs), especially in monoamnionic multifetal pregnancies, selective feticide by this method is often associated with miscarriage of the remaining fetuses. Selective fetal reduction in MMPs by blood flow ablation using radiofrequency ablation or fetoscopic laser surgery may improve survival of the remaining fetus. Although often successful, MFPR by these methods is contraindicated in cases of twin reversed arterial perfusion (TRAP) sequence in triplet pregnancies complicated by polyhydramnios or anterior placenta, as it is difficult to locate the ablation target.

PATIENT CONCERNS

2 cases were admitted to Xiangya Hospital, Central South University with triplet pregnancies at 23 or 21weeks of gestation.

DIAGNOSES

Case 1 was a 29-year-old woman with a triplet pregnancy in 2 distinct amniotic sacs and 1 fetus with multiple malformations. Case 2 was a 32-year-old woman who was identified as a triplet pregnancy with TRAP sequence with an acardiac/acephalic twin and anterior placenta.

INTERVENTIONS

Both of the 2 cases were underwent a new method for MFPR involving fine needle amniotic fluid aspiration and injection of hypertonic sodium chloride (10% NaCl) into the Wharton jelly of the umbilical cord.

OUTCOMES

The 2 cases resulted in selective feticide and the birth of the remaining infants from the triplet pregnancies. All infants were healthy at birth and the 2-year follow-up.

LESSONS

The new approach provided a safer, more accessible, and more cost-effective method for MFPR in MMPs with a contraindication to fetoscopic surgery compared to radiofrequency ablation and fetoscopic laser surgery.

Intervention versus a conservative approach in the management of TRAP sequence: a systematic review

OBJECTIVE

In the management of twin reversed arterial perfusion (TRAP) sequence, we wished to (i) determine if intervention is better than a conservative approach and (ii) assess if any of the apparent adverse prognostic indicators could guide intervention.

METHODS

A systematic review was conducted between 1994 and 2014. Data extracted were inspected for heterogeneity. Overall rates and confidence intervals (CIs) for each prognostic factor were calculated. Where there were comparative data, the odds ratio (OR) was calculated.

RESULTS

Twenty-six studies were included in the review. When all cases were considered, intervention either by cord occlusion or by ablation conferred a better survival rate compared with conservative management (OR=2.22, 95% CI 1.23-4.01, heterogeneity I2=37%, P=0.008). This difference was greater in the presence of one or more poor prognostic features (OR=8.58, 95% CI 1.47-49.96, heterogeneity I2=0%, P=0.02). Survival was better using ablative techniques compared to cord occlusion (OR=9.84, 95% CI 1.56-62.00, heterogeneity I2=0%, P=0.01).

CONCLUSION

Intervention either by cord occlusion or by ablation confers a better survival rate compared to conservative management. This appears more compelling if there are one or more poor prognostic features. Ablative techniques are superior to cord occlusion. There were insufficient data to determine which poor prognostic features should guide management.

Clinical Outcomes after Selective Fetal Reduction of Complicated Monochorionic Twins with Radiofrequency Ablation and Bipolar Cord Coagulation

AIMS

To review pregnancy outcomes, complication rates and neonatal neural development of selective termination procedures for complicated monochorionic (MC) twins.

METHODS

This was a retrospective review of the pregnancies that underwent selective reduction with radiofrequency ablation (RFA) and bipolar cord coagulation (BCC) in our institution.

RESULTS

Forty-eight cases underwent selective reduction with BCC and the remaining 45 with RFA. Overall survival was not statistically different between the RFA and BCC groups (71.1 and 62.5%, p = 0.379). With regard to the indications, the survival rates were not significantly different for twin to twin transfusion syndrome, twin reversed arterial perfusion, discordant anomalies and selective intrauterine growth restriction. Preterm premature rupture of membrane was not statistically different between the BCC and RFA groups (47.9 and 33.3%, p = 0.153). Five foetuses presented with abnormal middle cerebral artery-peak systolic velocity in the BCC group and 4 in the RFA group (p = 0.829). In the BCC group, neurological injury was detected in 2 neonates, presenting with cerebral dysplasia on MR scanning. In the RFA group, intracranial haemorrhage Grade III was detected in one neonate with cranial ultrasound (p = 0.607).

CONCLUSIONS

Overall survival and complication rates following selective reduction in complicated MC twin pregnancies is similar irrespective of whether the reduction was performed using RFA or BCC. Key Message: It seems that selective reduction in MC pregnancies with RFA does not carry a significant decrease in the overall survival and complication rates than the cases with BCC. According to our data, neurodevelopmental impairment of the co-twins is relatively seldom after selective reduction.

Forty cases of twin reversed arterial perfusion sequence treated with radio frequency ablation using the multistep coagulation method: a single-center experience

OBJECTIVE

To report the pregnancy outcomes of patients with twin reversed arterial perfusion (TRAP) sequence treated by radiofrequency ablation (RFA).

METHODS

This was a retrospective study of TRAP sequences treated in a single center between March 2002 and February 2015. Forty patients underwent RFA with expandable tines through a multistep coagulation method between 15 and 26 gestational weeks. The primary outcome was neonatal survival to discharge.

RESULTS

The overall survival of the pump twin was 85%. The survival rates in monochorionic-monoamniotic (MCMA) pregnancies and monochorionic-diamniotic pregnancies were 66.7% (4/6) and 87.9% (29/33), respectively. One triplet was treated successfully and delivered at 36 weeks of gestation. One of 35 live births (2.9%) had preterm premature rupture of membranes less than 34 weeks, resulting in infant death. In five intrauterine pump twin deaths, two cases were MCMA twins with cord entanglement, and three cases were MCDA twins with acardius anceps.

CONCLUSIONS

Our study supports the effectiveness of RFA for TRAP sequence after 15 weeks of gestation. The presence of MCMA twins or acardius anceps is associated with a high risk of pump twin death after RFA. © 2016 John Wiley & Sons, Ltd.

Radiofrequency Ablation with an Internally Cooled Electrode for Twin Reversed Arterial Perfusion Sequence

OBJECTIVE

The study aims to evaluate the efficacy of radiofrequency ablation (RFA) with an internally cooled electrode for twin reversed arterial perfusion (TRAP) sequence.

METHODS

From April 2008 through December 2014, we retrospectively reviewed all patients who underwent RFA with an internally cooled electrode for TRAP sequence at 3 tertiary referral centers in Japan.

RESULTS

Twenty-five monochorionic diamniotic twin pregnancies underwent RFA with an internally cooled electrode for TRAP sequence at 16-27 weeks of gestation. In all cases, umbilical cord blood flow cessation in the acardiac twin was confirmed by ultrasonography with color Doppler. There were 2 cases of procedure-related complications: 1 case of unintentional septostomy and 1 case of anemia in a pump twin. Fetal demise of the pump twin occurred in 3 (12%) cases. Twenty-two (88%) of 25 pump twins were delivered alive. The median gestational age at delivery was 36 + 3 weeks (range 25 + 2-40 + 5 weeks). There were 14 cases (64%) of premature deliveries before 37 weeks and 5 (23%) before 32 weeks.

CONCLUSION

RFA with an internally cooled electrode is a feasible and effective procedure for the treatment of TRAP sequence.

Selective reduction in complicated monochorionic twins: prediction of obstetric outcome and comparison of techniques

OBJECTIVES

To compare the outcomes of radiofrequency ablation (RFA) and bipolar cord coagulation (BPC) methods for selective feticide in complicated monochorionic (MC) twin gestations and to determine risk factors for adverse pregnancy outcome.

METHODS

This was a retrospective cohort study of all patients with complicated MC twin pregnancy who underwent selective reduction in a single tertiary care center between 2000 and 2014. We compared the two methods with respect to various demographic, obstetric and perinatal outcome variables.

RESULTS

Fifty-three selective terminations in complicated MC twin gestations were performed, 36 by RFA and 17 by BPC. Each technique resulted in a similar overall survival rate of the remaining twin (88.9% vs 76.5%, P = 0.25). Likewise, the mean procedure-to-delivery interval, the rate of spontaneous preterm delivery < 37, < 34, < 32 and < 28 weeks and the rate of preterm prelabor rupture of the membranes did not differ between the groups. However, among patients in the BPC group, there was a trend towards earlier gestational age at delivery (31.3 vs 35.0 weeks, P = 0.09) compared with in the RFA group. There was selective reduction by RFA due to selective intrauterine growth restriction (sIUGR) in 19 cases, 17 (89.5%) of which survived perinatally, with delivery at a median gestational age of 37 weeks. There were no significant differences in perinatal outcome, irrespective of whether the procedure was performed pre- or post-viability. All post-viability reductions, most of which were by RFA, resulted in perinatal survival.

CONCLUSIONS

Perinatal outcome of complicated MC twin gestations undergoing selective feticide seems to be similar regardless of whether termination is by BPC or RFA. Nevertheless, RFA appears to be particularly useful in MC twins complicated by sIUGR and in cases requiring selective reduction beyond the age of viability.

The North American Fetal Therapy Network Consensus Statement: Management of Complicated Monochorionic Gestations

The North American Fetal Therapy Network is a consortium of 30 medical institutions in the United States and Canada with established expertise in fetal therapy and other forms of multidisciplinary care for complex fetal disorders. This publication is the third in a series of articles written by NAFTNet about monochorionic pregnancies. In this article, we provide the general obstetric practitioner with information regarding management options available for complications of monochorionic gestations. This information may be useful for a better understanding of the pathophysiology of the various conditions, for better patient counseling, for timely referral to a regional treatment center, and for ongoing comanagement after treatment.

Systematic review and metaanalysis of perinatal outcomes after radiofrequency ablation and bipolar cord occlusion in monochorionic pregnancies

The aim of this study was to analyze perinatal outcomes after selective reduction in monochorionic pregnancies with the use of either radiofrequency ablation (RFA) or bipolar cord occlusion (BCO). This was a systematic review and metaanalysis that included all studies with ≥5 cases that described perinatal outcomes after BCO or RFA that were identified in PubMed, Embase, Web of Science, COCHRANE, CINAHL, Academic Search Premier, Science Direct, and MEDLINE that were published between 1965 and July 2014. For count data, incidence risk ratios (IRR; 95% confidence interval [CI]) were calculated with BCO as the reference standard. The analysis included 481 cases of BCO and 320 cases of RFA from 17 studies. The mean median gestations at procedure were 21.1 ± 1.2 weeks (BCO) and 18.8 ± 2.5 weeks (RFA; P = .03). The rate of cotwin death was higher in the RFA group (14.7%) vs the BCO group (10.6%; IRR, 1.38; 95% CI, 0.93-2.05; P = .11). The live birth rate was 81.3% for the RFA group and 86.7% in the BCO group (IRR, 0.93; 95% CI, 0.80-1.09; P = .41). BCO had higher neonatal death rates (8.1%) vs RFA (4.5%; IRR, 0.56; 95% CI, 0.30-1.04; P = .07). Overall survival was 76.8% for RFA and 79.1% for BCO (IRR, 0.97; 95% CI, 0.82-1.14; P = .72); however, none of these differences were statistically significant. Preterm premature rupture of membranes occurred in 17.7% of RFA cases and 28.2% of the BCO cases (IRR, 0.63; 95% CI, 0.43-0.91; P = .01). The mean median gestational age at delivery was 34.7 ± 1.7 weeks in the RFA group and 35.1 ± 1.6 weeks in the BCO group. Our data do not demonstrate clearly the superiority of 1 procedure over the other. The clinical situation and preference of the operator are important considerations. Rates of preterm delivery and preterm premature rupture of membranes remain substantial for both procedures.

Histologic changes of the fetal membranes after fetoscopic laser surgery for twin-twin transfusion syndrome

BACKGROUND

Preterm premature rupture of membranes remains a major complication after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS). We studied the histologic changes of fetal membranes post-FLS and investigated a possible impact of amniotic fluid (AF) dilution.

METHODS

Fetal membranes of 31 pregnancies that underwent FLS for TTTS were investigated histologically at delivery at different sites: trocar site of recipient sac and at distance, donor sac, and inter-twin membrane.

RESULTS

The trocar insertion site on the recipient sac showed no signs of histologic hallmarks of healing. Wide-spread alteration in collagen organization and higher apoptotic index in the amnion of the recipient sac which were absent in donor's and reference membranes. To explain the mechanisms, we analyzed the AF composition of recipient sacs from TTTS pregnancies vs. GA-matched healthy singleton controls and found glucose, protein and lactate dehydrogenase activity were all significantly lower in TTTS sacs consistent with over-dilution of recipient's AF (~2-fold). In-vitro exposure of healthy amniochorion to analogous dilutional stress conditions recapitulated the histologic changes and induced apoptosis and autophagy.

CONCLUSION

Alteration in structural integrity of the recipient's amniochorion, possibly in response to dilution stress, along with ineffective repair mechanisms may explain the increased incidence of preterm birth post-FLS.

Screening and Invasive Testing in Twins

Prenatal screening and testing for trisomy 21 in twin pregnancies poses a number of challenges: the exact estimate of the a priori risk of trisomy 21, the choice of prenatal screening test and/or invasive techniques to employ for the diagnosis and the impact of the result on the options of treatment in case of discordant results within a twin pair or among multiples. These different aspects are discussed below while recognizing that many issues remain unresolved.

Perinatal outcome after selective feticide in monochorionic twin pregnancies

OBJECTIVE

To evaluate the incidence and risk factors of adverse perinatal outcome in complicated monochorionic twin pregnancies treated with selective feticide.

METHODS

This was a retrospective analysis of prospectively collected data from a consecutive, national cohort. All monochorionic twin pregnancies treated with selective feticide at Leiden University Medical Center between June 2000 and November 2011 were included. Obstetric and neonatal data were recorded. The primary outcome measure was adverse perinatal outcome, including fetal or neonatal demise or severe neonatal morbidity.

RESULTS

Data on perinatal outcome were obtained in all cases (n = 131). Overall perinatal survival rate was 67.2% (88/131). Median gestational age at delivery was 34 (interquartile range, 23-38) weeks. Neonatal mortality and morbidity rate in liveborn children was 4.3% (4/92) and 12.0 % (11/92), respectively. Severe cerebral injury was detected in three children. The overall incidence of adverse perinatal outcome was 41.2% (54/131). Median gestational age at occurrence of preterm prelabor rupture of membranes (PPROM) was 19.0 weeks and 32.0 weeks in cases with and without adverse perinatal outcome, respectively (P = 0.017). Liveborn children with adverse perinatal outcome were born at a lower median gestational age (29.0 weeks) than were children without adverse perinatal outcome (38.0 weeks) (P < 0.001).

CONCLUSIONS

The risk of adverse perinatal outcome after selective feticide is high and associated with low gestational age at occurrence of PPROM and low gestational age at delivery. Long-term follow-up to assess neurodevelopmental outcome in survivors is required.

[Pediatric outcome after selective feticide for 30 complicated monochorionic twin pregnancies]

OBJECTIVES

To describe perinatal and pediatric outcome after selective feticide for complicated monochorionic twin pregnancy.

PATIENTS AND METHODS

We reviewed all consecutive cases of umbilical cord occlusion performed for complicated monochorionic twin pregnancy over a 16-year period. Pediatric follow-up was based on medical records and updated by phone calls to the parents.

RESULTS

Thirty procedures were performed. Indications were: twin-to-twin transfusion syndrome (TTTS) progressing despite serial amniodrainage (n=12) ; twin reversed arterial perfusion (n=9) ; selective growth restriction (n=5) ; severe discordant structural anomalies (n=4). Mean gestational age at procedure was 21.8±3.1gestational weeks (GW) and 31.8±4.8 GW at birth. Overall survival rate was 87%, i.e. 83%, 100%, 60% and 100% for each indication, respectively. Mean pediatric follow-up was 5years (range: 6months to 15years). Medical charts and parents declared normal development in 88% of surviving children, i.e. 67%, 100%, 100%, and 100% for each indication. Cross-comparison between the four groups revealed that in the TTTS group, gestational age at procedure was more advanced (P=0.01) while delivery was slightly earlier (P=0.1), and pediatric development was poorer (P=0.02).

DISCUSSION AND CONCLUSION

Pediatric outcome after selective feticide appeared to be poorer for TTTS progressing despite serial amniodrainage than for other indications.