Fetoscopic laser ablation of placental vessels in severe previable twin-twin transfusion syndrome

The Rearing of Maternal-Fetal Surgery: The Maturation of a Field from Conception to Adulthood

Maternal-fetal surgery is fraught with inherent controversy from within the medical community and general public. Despite these challenges, the field of maternal-fetal surgery evolved into an international enterprise. Carefully nurtured by pioneers with foresight and resilience, the field navigated ethical dilemmas with rigorous scientific methodology, collaboration, transparency, and accordance. These central pillars are consistent throughout the brief but momentous history of maternal-fetal surgery, serving as the catalyst for its success. The maturation of fetal intervention is an exemplar of technological innovation propelling clinical innovation, as well as a celebration of mastering the delicate balance between caution and optimism.

Infantile neurodevelopmental outcome after fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome: the first prospective experience from Iran

Objective

We sought to evaluate the neurodevelopmental outcomes at 12 months of age among infants with twin-to-twin transfusion syndrome (TTTS) undergoing fetoscopic laser photocoagulation (FLP).

Materials and methods

In this prospective longitudinal study, neurodevelopmental assessment was performed among the infants at the corrected age of 12 months, who were diagnosed with TTTS and treated by FLP. The Ages and Stages Questionnaire (ASQ) was filled out by parents. In the next step in infants with abnormal ASQ, motor and cognitive developments were evaluated by Bayley’s infant and toddler development scoring system (Bayley 3-Third edition).

Results

In 39 FLP procedures the rate of live birth of at least one twin was 73.8%. Four neonatal deaths were recorded, three of which were due to prematurity and one was due to heart anomaly. The ASQ was normal in 89.7% (35/39) of the infants (group I), 5.1% (2/39) had minor neurodevelopmental impairment (NDI) (group II), and 5.1% (2/39) had major NDI (group III). The 4 infants with abnormal ASQ had Bayley examination which showed two with mild to moderate cerebral palsy and two had delayed verbal skills and autistic spectrum disorder. No significant difference was noted between survivors with and without NDI with respect to donor or recipient status, birth weight, gestational age at birth, Quintero stage of TTTS. In addition, the relationship between gestational age at the time of undergoing FLC and NDI was not significant.

Conclusion

In our population, minor and major neurodevelopmental impairment were seen in 10.2% of the infants. This information is useful for counseling our couples in this population prior the procedure.

Elective fetal reduction by radiofrequency ablation in monochorionic diamniotic twins decreases adverse outcomes compared to ongoing monochorionic diamniotic twins

BACKGROUND

Multifetal pregnancy reduction is a technique used to reduce the fetal number to mitigate the risks of adverse outcomes associated with multiple gestations. Monochorionic diamniotic twin pregnancies are subject to unique complications, contributing to adverse pregnancy outcomes. Thus, patients have an option to electively reduce 1 fetus to improve outcomes.

OBJECTIVE

This study aimed to compare outcomes of elective reduction of monochorionic diamniotic twins by radiofrequency ablation to planned ongoing monochorionic diamniotic twins.

STUDY DESIGN

We performed a retrospective review of 315 monochorionic diamniotic twin gestations that underwent first-trimester ultrasound within 1 institution. Planned electively reduced twins were compared with ongoing monochorionic diamniotic twins. All reductions were performed via radiofrequency ablation of the cord insertion site into the fetal abdomen. The primary outcome was preterm birth at <36 weeks' gestation. Secondary outcomes included gestational age at delivery; preterm birth at less than 37-, 34-, 32-, and 28-weeks' gestation; unintended loss; and adverse perinatal outcomes.

RESULTS

Among 315 monochorionic diamniotic pregnancies, 14 (4.4%) underwent elective multifetal pregnancy reduction, and 301 (95.6%) were planned ongoing twins. The mean gestational age of radiofrequency ablation in the elective multifetal pregnancy reduction group was 15.1±0.68 weeks. Patients who underwent elective multifetal pregnancy reduction had significantly higher maternal age (P<.01) and were more likely to be Asian (P<.01). Moreover, they were more likely to have undergone in vitro fertilization (P=.03) and chorionic villus sampling (P<.01). There was a significantly higher rate of term deliveries in the elective radiofrequency ablation group compared with ongoing twins (gestational age, 38 weeks [interquartile range, 36.1-39.1] vs 35.9 weeks [interquartile range, 34.0-36.9]; P<.01). Patients with ongoing pregnancies had a trend of increased rate of preterm birth at <36 weeks' gestation (odds ratio, 3.4; 95% confidence interval, 1.0-12.0; P=.06), a significantly increased risk of preterm birth at <37 weeks' gestation (odds ratio, 8.0; 95% confidence interval, 2.4-26.4; P<.01), and no difference at less than 34-, 32-, or 28- weeks' gestation. All patients who underwent elective radiofrequency ablation had successful pregnancies with no pregnancy losses or terminations. Of ongoing gestations, 36 required procedures, including 16 (5.3%) medically indicated radiofrequency ablation, 14 (4.6%) laser ablation, and 6 (1.9%) amnioreductions. Furthermore, 22 patients (7.3%) with planned ongoing twins had total pregnancy loss at <24 weeks' gestation. Notably, 12 patients (4.0%) had unintended loss of 1 fetus before 24 weeks' gestation in the ongoing pregnancy cohort, and 12 patients (4.0%) had unintended loss of both fetuses before 24 weeks' gestation. Moreover, 5 patients (1.7%) in the ongoing pregnancy group had intrauterine fetal demise at >24 weeks' gestation and 10 patients (3.3%) electively terminated both fetuses. There was no significant difference in loss rates between the 2 groups.

CONCLUSION

In this study of monochorionic diamniotic twins, patients who elected to undergo multifetal pregnancy reduction had significantly lower rates of preterm birth at <37 weeks and a lower trend of preterm birth at <36 weeks' gestation without an increased risk of pregnancy loss. Median gestational age at delivery was significantly higher in the elective multifetal pregnancy reduction group (38 weeks) than in the ongoing pregnancy group (35.9 weeks). Further research is needed to clarify if multifetal pregnancy reduction improves long-term outcomes.

Modern fetal surgery-a historical review of the happenings that shaped modern fetal surgery and its practices

The history of fetal surgery is one of constant evolution. Over the last 50 years, fetal surgery has progressed from a mere idea to an internationally respected innovative field of surgery. This article aims to provide a historical review of how the enterprise of maternal-fetal surgery came to be its modern version. This review is less focused on the history of specific therapies for a relatively small number of conditions, and more on how the whole field of maternal-fetal surgery evolved. The various internal and external influences that steered the field's evolution are discussed in chronologic order. Since the start of modern fetal surgery in the 1980s, large paradigm shifts have characterized the growth of the field as a whole. Innovative interventions are now based on physiologic manipulation as opposed to simple anatomic repair, fetoscopy has become the more frequently preferred surgical approach, and rigorous scientific evaluation with randomized controlled trials is now the standard expected by the community. In a very similar fashion to when the field first began in the early 1980s, recently community's leaders have risen to protect the integrity of maternal-fetal surgery by publishing ethical guidelines for innovation and clinical practice. This incredible history of innovation, rigorous science and ethical contemplation is the foundation on which modern maternal-fetal surgery rests.

Error traps in fetal surgery

The growth of the field of fetal surgery over the last two decades driven by new indications and data from prospective randomized trials supporting prenatal intervention has resulted in techniques protocols and methodologies that have gained confidence by insuring good outcomes. Error traps are methods or techniques that usually work well in most of the cases, but which are apt to fail under certain specific circumstances. The very confidence the surgeon develops in these techniques or methodologies makes them a trap for the unwary surgeon. The purpose of this article is to discuss common error traps in fetal interventions, including ultrasound guided procedures, fetoscopic surgery, open fetal surgery and EXIT procedures. Awareness of these error traps and approaches to avoid them may enhance fetal surgical outcomes and reduce complications rates.

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.

Outcome after fetoscopic laser coagulation in twin-twin transfusion syndrome - is the survival rate of at least one child at 6 months of age dependent on preoperative cervical length and preterm prelabour rupture of fetal membranes?

Purpose: Twin-to-twin transfusion syndrome (TTTS) complicates 10-15% of all monochorionic twin pregnancies. Selective laser coagulation of placental anastomoses is the only causal therapy. The aim of this study was to analyze the neonatal survival, the survival rate of at least one child at 6 months of age, and maternal outcome after laser therapy in a Swiss cohort.Material and methods: Between 2008 and 2014, 39 women were treated with fetoscopic laser procedure due to TTTS. Two women were excluded from the study because of missing informed consent or loss of follow-up. The women were divided into two groups: group 1 with a cervical length >25 mm and group 2 with a cervical length ≤25 mm. The primary end point was the survival rate of at least one child at 6 months of age and its dependence on maternal preoperative cervical length or the time interval between operation (OP)-preterm prelabour rupture of fetal membranes (PPROM). Secondary outcomes were neonatal complications and maternal complications due to the procedure. Statistical analysis was performed using the program SPSS 22. A p-value of <.05 was considered statistically significant.Results: Mean gestational age (GA) at OP of group 1 (20.3 ± 3 GW) was comparable with group 2 (21.5 ± 2.4 GW; p = .27). The GA at birth was significantly higher in group 1 (31.5 ± 5.9 GW) than in group 2 (27.0 ± 4.7 GW: p = .02). The survival rate of at least one child at 30 days and 6 months of age was 81% in group 1 and only 60% in group 2 (p = .1). PPROM <32 GW occurred in 43%. The survival rate of at least one child was significantly higher if the OP-PPROM interval was >28 days (93 versus 43%; p = .02). Major brain injury was observed in 11% of infants. Severe maternal complications (pulmonary edema) occurred in three cases (8%).Conclusions: Our survival rate of at least one child at 30 days and 6 months of age and the outcome of the mothers is well comparable to other international studies. A preoperative maternal cervical length of >25 mm and an occurrence of PPROM more than 28 days after the laser therapy is associated with a higher survival rate of at least one child at 6 months of age.

Transient amniotic fluid leakage after fetoscopic laser photocoagulation for twin-twin transfusion syndrome

AIM

Iatrogenic premature rupture of membrane (PROM) is one of the major complications related to fetoscopic laser photocoagulation (FLP) for twin-twin transfusion syndrome (TTTS). However, amniotic fluid leakage (AFL) sometimes spontaneously disappears. This study evaluated the incidence and clinical characteristics of transient AFL after FLP.

METHODS

We retrospectively reviewed pregnancies that underwent FLP for TTTS at a single center. Patients with apparent AFL within 2 weeks after FLP were divided into two groups: transient AFL, defined by the disappearance of fluid leakage within a week; and PROM, if AFL persisted continuously for more than a week or premature birth occurred, including miscarriage, within a week of the first symptom of AFL.

RESULTS

Among 201 monochorionic twin pregnancies that underwent FLP during the study period, nine patients (4.5%) were diagnosed with AFL within a week after FLP. Four patients (2.0%) were classified as transient AFL and five as PROM. Median gestational age at FLP was not significantly different between the groups; operative time in the PROM group was significantly longer (P = 0.01). The surgery to delivery interval and median gestational age at delivery were greater in the transient AFL group (87.8 vs 17.6 days, P = 0.01; 32.5 vs 23.6 weeks, P = 0.01, respectively).

CONCLUSIONS

The incidence of transient AFL after FLP was 2%. Perinatal outcomes of transient AFL might be better than that of PROM.

Fetoscopic laser photocoagulation in twin-to-twin transfusion syndrome: experience from a single institution

INTRODUCTION

Twin-to-twin transfusion syndrome (TTTS) is the most common serious complication of monochorionic (MC) twin pregnancies, with perinatal mortality rates of up to 90% if untreated. This study aimed to review the perinatal and perioperative outcomes of MC twin pregnancies treated for TTTS by fetoscopic laser photocoagulation (FLP) since its introduction at KK Women's and Children's Hospital (KKH), Singapore, in 2011.

METHODS

This was a retrospective review of five consecutive patients who underwent FLP of placental anastomoses for TTTS at KKH from June 2011 to March 2014. FLP was offered to patients who were diagnosed with TTTS of at least Quintero Stage II before 26 weeks of gestation. The main outcome measures were perioperative complications and perinatal survival rates.

RESULTS

Five sets of MC twin pregnancies underwent FLP during the study period - three pregnancies were diagnosed with Stage III TTTS and two pregnancies with Stage II TTTS. Median gestational ages at initial presentation, laser photocoagulation and delivery were 19 (range 17-20) weeks, 20 (range 19-23) weeks and 29 (range 28-34) weeks, respectively. One patient had bleeding into the amniotic cavity intraprocedurally. Overall, the perinatal survival rate, double-infant survival rate and survival rate for at least one twin were 60% (6/10 fetuses), 40% (2/5 twins) and 80% (4/5 twins), respectively.

CONCLUSION

FLP is a feasible treatment for TTTS, with minimal maternal complications. Perinatal survival rates of this patient group that was managed at our centre were comparable to those of international centres.

Preterm prelabor rupture of membranes after fetoscopic laser surgery for twin-twin transfusion syndrome

OBJECTIVE

To assess the incidence, clinical course, risk factors and outcomes of preterm prelabor rupture of membranes (PPROM) after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS).

METHODS

This was a prospective observational cohort study of 154 consecutive cases of TTTS. PPROM was defined as rupture of membranes before 34 weeks' gestation. Procedure-to-PPROM and PPROM-to-delivery intervals were determined. Relevant preoperative and intraoperative variables were analyzed by univariate and multivariate logistic regression to determine their impact on PPROM after FLS.

RESULTS

The incidence of PPROM was 39% (n = 60), occurring at a mean gestational age of 27.2 ± 4.6 weeks. Median procedure-to-PPROM interval was 46 (range, 1-105; interquartile range (IQR), 13-66) days and median PPROM-to-delivery interval was 1 (range, 0-93; IQR, 0-13) day. Mean gestational age at delivery in cases with PPROM was 29.0 ± 4.5 weeks compared with 32.6 ± 3.9 weeks in cases without PPROM (P < 0.0001). Insertion of a collagen plug was the only significant factor found on both univariate and multivariate analysis to be associated with an increased rate of PPROM (odds ratio, 3.1 (95% CI, 1.2-8.0); P = 0.006). There was no statistically significant difference in fetal (P = 0.07) or neonatal (P = 0.08) survival between those with and those without PPROM.

CONCLUSIONS

PPROM after FLS increases prematurity by 3.6 weeks. The latency period after PPROM was 2 weeks; 50% of patients delivered within 24 h. No variable thought to be associated with PPROM after FLS was found to be significantly associated with this complication. Other etiologies and mechanisms for PPROM after FLS should be explored. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

[Fetoscopic laser coagulation in 200 consecutive monochorionic pregnancies with twin-twin transfusion syndrome]

OBJECTIVES

To report preoperative data, surgical characteristics, complications and perinatal outcome of twin-twin transfusion syndrome (TTTS) managed with laser ablation surgery, to analyze predictors of neonatal survival and to compare the 100 most recent cases with the older 100.

MATERIALS AND METHODS

Observational cohort moncentric study of 200 cases of TTTS consecutively treated with fetoscopic laser coagulation between January 2004 and December 2014.

RESULTS

There were 49 stage I, 88 stage II, 55 stage III and eight stage IV. Median gestation at time of laser was 20.1±3.0 weeks' gestation (WG) whereas median gestation at delivery was 31.6±5.4 WG. Overall perinatal survival rate was 68.0% and 84.0% have one or more surviving twins. Preterm premature rupture of membranes occurred in 39 cases with and the median gestational age for this complication was 28.8±4.6 SA. Predictive factors to have at least one living birth were Quintero stage and gestational age at delivery. In the most recent period, there were significantly more TTTS Quintero stage I treated with laser, more coagulation by the Solomon technique and a larger number of coagulated vessels.

CONCLUSION

The neonatal survival of TTTS is improved by fetoscopic laser coagulation, preferely by using Solomon tecnhique. The use of active management of stage I is currently on research.

Laser Treatment of Twin–to–Twin Transfusion Syndrome

Objective: Laser ablation of all placental vascular anastomoses is the optimal treatment for twin–twin transfusion syndrome (TTTS). However, two important controversies are apparent in the literature: (a) a gap between concept and performance, and (b) controversy regarding whether all the anastomoses can be identified endoscopically and whether blind lasering of healthy placenta is justified. The purpose of this article is: (a) to address the potential source of the gap between concept and performance by analyzing the fundamental steps needed to successfully accomplish the surgery, and (b) to discuss the resulting competency benchmarks reported with the different surgical techniques. Materials and Methods: Laser surgery for TTTS can be broken down into two fundamental steps: (1) endoscopic identification of the placental vascular anastomoses, (2) laser ablation of the anastomoses. The two steps are not synonymous: (a) regarding the endoscopic identification of the anastomoses, the non-selective technique is based upon lasering all vessels crossing the dividing membrane, whether anastomotic or not. The selective technique identifies and lasers only placental vascular anastomoses. The Solomon technique is based on the theory that not all anastomoses are endoscopically visible and thus involves lasering healthy areas of the placenta between lasered anastomoses, (b) regarding the actual laser ablation of the anastomoses, successful completion of the surgery (i.e., lasering all the anastomoses) can be measured by the rate of persistent or reverse TTTS (PRTTTS) and how often a selective technique can be achieved. Articles representing the different techniques are discussed. Results: The non-selective technique is associated with the lowest double survival rate (35%), compared with 60–75% of the Solomon or the Quintero selective techniques. The Solomon technique is associated with a 20% rate of residual patent placental vascular anastomoses, compared to 3.5–5% for the selective technique (p < .05). Both the Solomon and the selective technique are associated with a 1% risk of PRTTTS. Adequate placental assessment is highest with the selective technique (99%) compared with the Solomon (80%) or the ‘standard’ (60%) techniques (p < .05). A surgical performance index is proposed. Conclusion: The Quintero selective technique was associated with the highest rate of successful ablation and lowest rate of PRTTTS. The Solomon technique represents a historical backward movement in the identification of placental vascular anastomoses and is associated with higher rate of residual patent vascular communications. The reported outcomes of the Quintero selective technique do not lend support to the existence of invisible anastomoses or justify lasering healthy placental tissue.

Twin-to-Twin Transfusion Syndrome: From Observational Evidence to Randomized Controlled Trials

Fetoscopic surgery is widely accepted as the preferred first-line treatment for twin-twin transfusion syndrome (TTTS). Nonetheless, the broad diffusion of this technique relies on a single multicentric-randomized trial. We hereby question this trial in a post-hoc Bayesian analysis, submitting its results to several scenarios comprising the alternative published non-randomized literature and pessimistic opinions regarding this surgery. Furthermore, we also discuss further refinements in indications, questioning potential alternatives in early stages of the disease.

Twenty-Five Years of Fetoscopic Laser Coagulation in Twin-Twin Transfusion Syndrome: A Systematic Review

Objective: The aim of this study was to assess the perinatal outcome of pregnancies with twin-twin transfusion syndrome (TTTS) treated with laser therapy over the past 25 years, and in relation to different techniques used in this time period. Methods: A systematic review of studies reporting on perinatal outcome according to the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines was conducted. The MEDLINE, Embase and Cochrane Library databases were systematically searched. Comparisons were made in respect to time period and laser technique and Quintero stages. Results: In total, 34 studies reporting on 3,868 monochorionic twin pregnancies were included. The mean survival of both twins increased from 35 to 65% (p = 0.012) and for at least one twin from 70 to 88% (p = 0.009) over the past 25 years. Mean gestational age at birth remained stable over the years at 32 weeks gestation. Also, we showed a significantly improved perinatal survival with the evolution of the laser technique from non-selective to selective, selective sequential and the Solomon technique (p = 0.010). Discussion: Since the introduction of laser therapy for TTTS more than two decades ago, perinatal survival improved significantly. Improved outcome is probably associated with several factors, including evolution of the laser technique, learning curve effect, better referral and improved early neonatal care.

Maternal and fetal safety of fluid-restrictive general anesthesia for endoscopic fetal surgery in monochorionic twin gestations

STUDY OBJECTIVE

To review our experience with general anesthesia in endoscopic fetal surgery for twin-to-twin transfusion syndrome (TTTS), and to compare fetomaternal outcome before and after protocol implementation.

DESIGN

Retrospective impact study.

SETTING

University-affiliated medical center.

MEASUREMENTS

Data from 85 consecutive patients who underwent endoscopic laser ablation of placenta vessels for severe TTTS were studied. Outcomes were compared in patients before (2000-2007) and after (2008-2012) a change to strict intraoperative intravenous (IV) fluid and liberal vasopressor management. Perioperative parameters (IV fluid administration, vasopressor use, maternal hemoglobin [Hb] concentration); maternal complication rate (respiratory, hemorrhagic); pregnancy outcome; and fetal and neonatal survival were recorded.

MAIN RESULTS

Patients in the early group (2000-2007; n = 55) received 1634 ± 949 mL of crystalloid fluid intraoperatively, compared with 485 ± 238 mL (P < 0.001; Student's t test) given to the late group (2008-2012; n = 30). Maternal pulmonary edema and any respiratory distress were seen in 5.5% and 12.7% of patients in the early group, respectively, and in none of the late group patients (P < 0.05; Chi-square analysis).

CONCLUSIONS

A significant risk of maternal respiratory complications exists after general anesthesia for endoscopic fetal surgery. Judicious fluid management significantly decreases this risk.

Interventions for the treatment of twin-twin transfusion syndrome

BACKGROUND

Twin-twin transfusion syndrome, a condition affecting monochorionic twin pregnancies, is associated with a high risk of perinatal mortality and morbidity. A number of treatments have been introduced to treat the condition but it is unclear which intervention improves maternal and fetal outcome.

OBJECTIVES

The objective of this review was to evaluate the impact of treatment modalities in twin-twin transfusion syndrome.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 May 2013).

SELECTION CRITERIA

Randomised and quasi-randomised studies of amnioreduction versus laser coagulation, septostomy versus laser coagulation or septostomy versus amnioreduction.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Three studies (253 women and 506 babies) were included. All three trials were judged to be of moderate quality. One study compared amnioreduction with septostomy (71 women), whilst the other two studies compared amnioreduction with endoscopic laser coagulation (182 women). Not all trials provided outcome data that could be included in all meta-analyses. Amnioreduction compared with laser coagulation Although there was no difference in overall death between amnioreduction and laser coagulation (average risk ratio (RR) 0.87; 95% confidence interval (CI) 0.55 to 1.38 adjusted for clustering, two trials) or death of at least one infant per pregnancy (RR 0.91; 95% CI 0.75 to 1.09, two trials), or death of both infants per pregnancy (average RR 0.76; 95% 0.27 to 2.10, two trials), more babies were alive without neurological abnormality at the age of six years in the laser group than in the amnioreduction groups (RR 1.57; 95% CI 1.05 to 2.34 adjusted for clustering, one trial). There were no significant differences in the babies alive at six years with major neurological abnormality treated by laser coagulation or amnioreduction (RR 0.97; 95% CI 0.34 to 2.77 adjusted for clustering, one trial). Outcomes for death in this 2013 update are different from the previous 2008 update, where improvements in perinatal death and death of both infants per pregnancy were shown in the laser intervention arm. The NIHCD trial included in this update exerts an opposite direction of effects to the Eurofetus study, which was previously the only included laser study, hence the difference in outcome. Amnioreduction compared with septostomy There are no differences in overall death (RR 0.83; 95% CI 0.47 to 1.47, adjusted for clustering, one trial), death of at least one infant per pregnancy (RR 0.80; 95% CI 0.48 to 1.35, one trial), or death of both infants per pregnancy (RR 0.90; 95% CI 0.37 to 2.22, one trial) or gestational age at birth (RR 1.20; 95% CI -0.81 to 3.21, one trial) between amnioreduction and septostomy.

AUTHORS' CONCLUSIONS

Endoscopic laser coagulation of anastomotic vessels should continue to be considered in the treatment of all stages of twin-twin transfusion syndrome to improve neurodevelopmental outcomes.Further research targeted towards assessing the effect of treatment on milder (Quintero stage 1 and 2) and more severe (Quintero stage 4) forms of twin-twin transfusion syndrome is required. Studies should aim to assess long-term outcomes of survivors.

Fetoscopic laser ablation of placental anastomoses in twin-twin transfusion syndrome using 'Solomon technique'

OBJECTIVE

To document perinatal outcomes following use of the 'Solomon technique' in the selective photocoagulation of placental anastomoses for severe twin-twin transfusion syndrome (TTTS).

METHODS

Between January 2010 and July 2012, data were collected from 102 consecutive monochorionic twin pregnancies complicated by severe TTTS that underwent fetoscopic laser ablation at four different centers. We compared outcomes between subjects that underwent selective laser coagulation using the Solomon technique (cases) and those that underwent selective laser coagulation without this procedure (controls).

RESULTS

Of the 102 pregnancies examined, 26 (25.5%) underwent the Solomon technique and 76 (74.5%) did not. Of the 204 fetuses, 139 (68.1%) survived up to 30 days of age. At least one twin survived in 82 (80.4%) pregnancies and both twins survived in 57 (55.9%) pregnancies. When compared with the control group, the Solomon-technique group had a significantly higher survival rate for both twins (84.6 vs 46.1%; P < 0.01) and a higher overall neonatal survival rate (45/52 (86.5%) vs 94/152 (61.8%); P < 0.01). Use of the Solomon technique remained independently associated with dual twin survival (adjusted odds ratio (aOR), 11.35 (95% CI, 3.11-53.14); P = 0.0007) and overall neonatal survival rate (aOR, 4.65 (95% CI, 1.59-13.62); P = 0.005) on multivariable analysis. There were no cases of recurrent TTTS or twin anemia-polycythemia sequence (TAPS) in the Solomon-technique group.

CONCLUSIONS

Use of the Solomon technique following selective laser coagulation of placental anastomoses appears to improve twin survival and may reduce the risk of recurrent TTTS and TAPS. Our data support the idea of performing a randomized controlled trial to evaluate the effectiveness of the Solomon technique.

Intrauterine Myocardial Infarction in a Twin Gestation Complicated by Twin-to-Twin Transfusion Syndrome

Twin-to-twin transfusion syndrome (TTTS) is a known complication of 10% to 15% of monochorionic/diamniotic twin gestations. It is also known that the “recipient” twin in these pregnancies is at higher risk for cardiac abnormalities. Early identification of TTTS and recognition of changes in fetal cardiac function can reduce fetal morbidity and mortality. This case describes intrauterine myocardial infarction developing in the recipient twin of a monochorionic/diamniotic twin gestation complicated by TTTS.

Perinatal Outcomes With Laser Surgery for Twin–Twin Transfusion Syndrome

The aim of this tertiary hospital–based cohort study was to determine and compare perinatal outcome and neonatal morbidities of pregnancies with twin–twin transfusion syndrome (TTTS) before and after the introduction of a treatment program with laser ablation of placental communicating vessels. Twenty-seven pregnancies with Stage II–IV TTTS treated with amnioreduction were identified (amnioreduction group). The data were compared with that obtained from the first 31 pregnancies with Stage II–IV TTTS managed with laser ablation of placental communicating vessels (laser group). Comparisons were made for perinatal survival and neonatal morbidities including abnormalities on brain imaging. The median gestation at therapy was similar between the two groups (20 vs. 21 weeks, p = .24), while the median gestation at delivery was significantly greater in the laser treated group (34 vs. 28 weeks, p = .002). The perinatal survival rate was higher in the laser group (77.4% vs. 59.3%, p = .03). Neonatal morbidities including acute respiratory distress, chronic lung disease, requirement for ventilatory assistance, patent ductus arteriosus, hypotension, and oliguric renal failure had a lower incidence in the laser group. On brain imaging, ischemic brain injury was seen in 12% of the amnioreduction group and none of the laser group of infants (p = .01). In conclusion, these findings indicate that perinatal outcomes are improved with less neonatal morbidity for monochorionic pregnancies with severe TTTS treated by laser ablation of communicating placental vessels when compared to treatment by amnioreduction.

The Effect of Treatment of Twin-Twin Transfusion Syndrome on the Diagnosis-to-Delivery Interval

No randomised controlled trials of treatment of twin-to-twin transfusion syndrome (TTTS) exist. Since severely preterm neonatal survival has increased over time, survival as an outcome measure is confounded by improvements in neonatal care. The diagnosis-to-delivery interval is a measure of success of treatment independent of improvements in neonatal care. We wished to evaluate whether treatment of TTTS is associated with a lengthening of the diagnosis-to-delivery interval. MEDLINE search was performed supplemented by careful reference review. All TTTS series were included where the following information on each patient was available: survival, fetal demise, gestational age at diagnosis and diagnosis-to-delivery interval in days. Inclusion criteria: gestational age at diagnosis < 29 weeks and diagnosis by ultrasound in the absence of maternal symptoms. Cases undergoing multiple types of treatment were excluded. Eight publications met inclusion criteria and included the following cases: controls (n = 16), amnioreduction (n = 61), septostomy (n = 12), and fetoscopic laser occlusion of chorioangiopagus vessels (n = 51). There was no difference in the diagnosis-to-delivery interval, overall survival, at least one survivor, or number of fetal deaths between the four groups. Logistic regression using at least one survivor as the dependent variable revealed a positive association with gestational age at diagnosis and with diagno-sis-to-delivery interval, a negative correlation with fetal death, and no correlation with treatment group. We conclude that there is no difference in diagnosis-to-delivery interval or survival for any treatment for TTTS compared to expectant management. The lack of significance appears to be due to small sample sizes.

[Favourable outcome after fetoscopic laser surgery for twin-twin transfusion syndrome: experience of an emerging centre]

OBJECTIVES

Our objective was to report perinatal outcome during the first three years of an emerging centre for laser photocoagulation in twin-twin transfusion syndrome (TTTS) and to compare with outcome observed earlier in the same centre when management consisted in recurrent amniodrainage.

PATIENTS AND METHODS

We conducted a single centre retrospective study. We compared perinatal outcome of 19 consecutive cases of mid trimester TTTS managed by amniodrainage over a 10-year period with 49 cases of TTTS managed by laser photocoagulation over a 3-year period.

RESULTS

Laser photocoagulation increased survival rate at birth (P=0.02) and at postnatal day 28 (P=0.01). Neurologic and cardiologic complications did not differ significantly (P=0.5 and P=0.3 respectively). We observed a significant increase in survival of the donor after laser coagulation at birth (P=0.04).

DISCUSSION AND CONCLUSION

Our study demonstrated better outcome after laser photocoagulation. Early results of an emerging centre appeared comparable to those of more experienced centres.

Laser therapy for twin-to-twin transfusion syndrome (TTTS)

Monochorionic twins are subjected to specific complications which originate in either imbalance or abnormality of the single placenta serving two twins including twin-to-twin transfusion syndrome. The diagnosis is well established in overt clinical forms with the association of polyuric polyhydramnios and oliguric oligohydramnios. The best treatment of cases presenting before 26 weeks of gestion is fetoscopic laser ablation of the intertwin anastomoses on the chorionic plate. Although subjected to subtle variations, the core technique follows robust guidelines which could help understanding and acquiring the required skills and experience to perform this procedure. However appropriate and tailored hands-on training and appropriate perinatal set-up are critical not only for surgical management but also for the follow-up and management of related complications.

Non-invasive pulsed cavitational ultrasound for fetal tissue ablation: feasibility study in a fetal sheep model

OBJECTIVES

Currently available fetal intervention techniques rely on invasive procedures that carry inherent risks. A non-invasive technique for fetal intervention could potentially reduce the risk of fetal and obstetric complications. Pulsed cavitational ultrasound therapy (histotripsy) is an ablation technique that mechanically fractionates tissue at the focal region using extracorporeal ultrasound. In this study, we investigated the feasibility of using histotripsy as a non-invasive approach to fetal intervention in a sheep model.

METHODS

The experiments involved 11 gravid sheep at 102-129 days of gestation. Fetal kidney, liver, lung and heart were exposed to ultrasound pulses (< 10 µs) delivered by an external 1-MHz focused ultrasound transducer at a 0.2-1-kHz pulse-repetition rate and 10-16 MPa peak negative pressure. Procedures were monitored and guided by real-time ultrasound imaging. Treated organs were examined by gross and histological inspection for location and degree of tissue injury.

RESULTS

Hyperechoic, cavitating bubble clouds were successfully generated in 19/31 (61%) treatment attempts in 27 fetal organs beneath up to 8 cm of overlying tissue and fetal bones. Histological assessment confirmed lesion locations and sizes corresponding to regions where cavitation was monitored, with no lesions found when cavitation was absent. Inability to generate cavitation was primarily associated with increased depth to target and obstructing structures such as fetal limbs.

CONCLUSION

Extracorporeal histotripsy therapy successfully created targeted lesions in fetal sheep organs without significant damage to overlying structures. With further improvements, histotripsy may evolve into a viable technique for non-invasive fetal intervention procedures.

Use of the Learning Curve-Cumulative Summation test for quantitative and individualized assessment of competency of a surgical procedure in obstetrics and gynecology: fetoscopic laser ablation as a model

OBJECTIVE

We sought to determine the learning curve (LC) for fetoscopic laser photocoagulation (FLP) as a model for the evaluation of training in surgical procedures.

STUDY DESIGN

A retrospective review of consecutive case series of FLP from 2 centers with 3 operators (operator I [O-I], observer trained; operator II [O-II], hands-on trained; and operator III [O-III], clinical fellow) was performed and the LC-cumulative summation (CUSUM) test was plotted.

RESULTS

The acceptable and unacceptable success rates for at least 1 fetus survival after FLP were set at 82% and 70%, respectively, from a systematic review. A total of 171 consecutive cases were performed by the 3 operators (O-I, 91; O-II, 49; and O-III, 31). From LC-CUSUM test O-I needed 60 procedures, O-II needed 20 procedures, and O-III needed 20 procedures to reach an acceptable performance rate for at least 1 survivor.

CONCLUSION

The LC-CUSUM test can be used to accurately assess the LC in a surgical procedure in obstetrics and gynecology. Hands-on trained operators exhibit a shorter LC.

Maternal complications of fetoscopic laser photocoagulation (FLP) for treatment of twin-twin transfusion syndrome (TTTS)

AIMS

Fetoscopic laser photocoagulation (FLP) has become standard therapy for severe twin-twin transfusion syndrome. Data on adverse maternal events are rare. We performed a literature review to obtain data on maternal complications of FLP.

METHODS

Extensive literature review, searching MEDLINE and other databases from 1990 to 2009, using MESH-terms and further keywords. Data extraction was performed using the following criteria: (i) maternal complications reported as primary or secondary outcome parameters; (ii) any comment on adverse maternal events.

RESULTS

Of 321 publications found 40 were included, comprising 1785 patients. The overall rate of adverse maternal events was 5.4%. In studies with systematic assessment (n=3, 379 patients) the complication rate was significantly higher (17.4% vs. 2.2%, P<0.0001). Adverse events were classified and the rate was 1.0% (1.8% vs. 0.8%, P=0.12) for severe complications; 2.9% (11.9% vs. 0.5%, P<0.0001) for intermediate/minor adverse events; and 1.5% (3.7% vs. 0.9%, P<0.0001) for complications with undetermined relevance.

CONCLUSIONS

High-quality data on maternal complications of FLP are rare. With systematic assessment, the rate of adverse events is significantly higher. Underreporting has to be assumed. Further studies are required to confirm these data.

Twin-twin transfusion syndrome: an ethics-based and evidence-based argument for clinical research

Aspects of twin-twin transfusion syndrome (TTTS) diagnosis, treatment alternatives, and research opportunities were considered during a consensus conference that was held by the North American Fetal Therapy Network in 2009. A 3-member scientific consensus panel gathered data from expert conference presentations, postconference communications, and comprehensive scientific literature database searches to develop recommendations for TTTS diagnosis, therapy, and research. The panel recommends retaining the Quintero staging system until a superior system has been validated appropriately. It concludes that there is normative equipoise to justify the performance of randomized clinical trials to identify the optimal treatment strategy for mild TTTS. Recommendations for the design and conduct of clinical trials and observational studies are also provided.

Chorioamnion plugging and the risk of preterm premature rupture of membranes after laser surgery in twin-twin transfusion syndrome

OBJECTIVE

To examine the incidence of preterm premature rupture of membranes (PPROM) in pregnancies affected by twin-twin transfusion syndrome (TTTS) treated with laser photocoagulation where an absorbable gelatin sponge was used as a chorioamnion sealant of the fetoscopic access port.

METHOD

A retrospective review was undertaken of consecutive cases undergoing fetoscopic directed laser surgery for TTTS between October 2006 and November 2008 at Texas Children's Fetal Center, in which an absorbable gelatin sponge, used as a chorioamnion 'plug', was placed at the conclusion of the intervention as a possible prophylactic measure to prevent PPROM. We excluded cases that had a failure of plug placement and those in which it was not attempted. PPROM was defined as rupture of membranes before 34 weeks' gestation. A comparison was performed between the PPROM group and a no-PPROM group to determine risk factors and outcomes.

RESULTS

Successful plug placement occurred in 79 of 84 cases (94%) in which it was attempted after laser surgery, with a rate of PPROM of 34% in these patients. PPROM occurred at an average gestational age of 26.5 +/- 3.6 weeks, with an average procedure-to-PPROM interval of 5.2 +/- 3.5 weeks. There were no statistically significant differences between the PPROM group and the no-PPROM group in maternal demographics or preoperative parameters including: amniotic fluid volumes in the recipient twin's gestational sac, volume of amnioreduction, and location of the placenta. The procedure-to-delivery interval for the total cohort (n = 79) was 9.2 +/- 4.7 weeks, without a significant difference between the two groups (P = 0.08). However, after exclusion of one PPROM outlier, the PPROM group had an average procedure-to-delivery time 2 weeks shorter than the group with no PPROM (P = 0.03). The live birth rates were similar in the PPROM and no-PPROM groups, at 77 and 73%, respectively. However, the average recipient's weight in the PPROM group was significantly lower than in the no-PPROM group (1321 +/- 493 vs. 1705 +/- 576 g; P = 0.02).

CONCLUSION

The rate of PPROM and the mean gestational age at delivery in pregnancies in which an absorbable gelatin sponge was used as a sealant of the fetoscopic port following laser photocoagulation for TTTS were comparable to those that have been reported by other laser centers where membrane sealants were not used. A randomized controlled trial should be considered to evaluate the effect of chorioamnion plugging.

Blood flow measurement system for fetoscopic laser photocoagulation of chorionic plate anastomosing vessels (FLPC)

Fetoscopic laser photocoagulation of chorionic plate anastomosing vessels (FLPC) applies to the treatment of previable fetuses with severe twin-twin transfusion syndrome (TTTS). The ultimate goal of FLPC is selective blood flow interruption of anastomotic communicating vessels on the placenta fetoscopically. However, there has not been an established method to confirm that the blood flow is blocked, thus, it depends on the operator's experience or intuition to evaluate whether the FLPC was performed successfully or not. For this issue, we have developed a composite-type optical fiberscope (2.2 mm in diameter), which has centrally-located cautery laser fiber and surrounding located fiberglasses for viewing. This fiberscope enables transmission of 50 W Yb fiber laser which can be focused to 10 mm focal length using two lenses on the fiberscope tip. In this study, we combined the fiberscope and a laser blood-flow meter, and irradiated cautery laser to porcine mesenteric vein with measuring blood flow at the same time. From the experimental results, we could quantitatively measure the blood flow before and after laser irradiation, and confirm the blood flow blocking with our system.

Management of severe twin to twin transfusion syndrome

In monozygotic twin pregnancies embryonic splitting within three days of fertilisation, which occurs in approximately one-third of cases, results in two separate fetuses with independent placental circulations. Splitting after the third day of fertilisation is associated with vascular communications between the placentae; when cleavage is delayed beyond day 12 the fetuses are conjoint. In some monochorionic twin pregnancies imbalance in the net flow of blood across the placental vascular communications from one fetus (the donor) to the other (the recipient) results in twin to twin transfusion syndrome (TTS).

Laparoscopy-assisted fetoscopy for laser surgery in twin-twin transfusion syndrome with anterior placentation

OBJECTIVE

To compare a laparoscopy-assisted fetoscopic approach with an ultrasound-directed percutaneous approach for laser photocoagulation of placental anastomoses in cases of twin-twin transfusion syndrome (TTTS) with anterior placentation.

METHOD

We performed a retrospective review of all cases that underwent laser ablation of placental anastomoses for TTTS with an anterior placenta at Texas Children's Fetal Center from November 2006 to November 2008. The two cohorts were identified by chart review based on the type of approach: laparoscopy-assisted vs. ultrasound-guided percutaneous uterine entry for fetoscopy. Operative and outcome data were extracted and the groups were compared using statistical methods, taking P < 0.05 as statistically significant.

RESULTS

In the 100 cases of TTTS studied, 48 had an anterior placenta. Fifteen (31%) of these underwent laparoscopy-assisted fetoscopy (LAF) while a percutaneous approach was used in the remaining 33 (69%) cases. The total procedure time was longer in the LAF group than in the percutaneous group (96.1 +/- 25 vs. 67.9 +/- 28 min; P < 0.01). There was no difference in the rate of preterm premature rupture of membranes up to 2 weeks and 4 weeks after surgery (7 vs. 15% and 13 vs. 21%, for the LAF group vs. the percutaneous group, respectively; P = 0.7). The gestational ages at delivery were similar: 30.3 +/- 4.5 weeks in the LAF group and 29.2 +/- 4.6 weeks in the percutaneous group (P = 0.32). The overall survival rate at birth was tending towards better survival in the laparoscopic group than in the percutaneous group (80 vs. 61%, respectively; P = 0.06). The neonatal survival rate was better with the LAF approach than with the percutaneous approach (80 vs. 59%, respectively; P = 0.045).

CONCLUSION

Laparoscopy-assisted entry of the uterus is associated with improved neonatal survival for laser photocoagulation in cases of TTTS with a complete anterior placentation.

Relationship of intertwin crown-rump length discrepancy to chorionicity, fetal demise and birth-weight discordance

OBJECTIVES

To study the frequency and clinical significance of crown-rump length (CRL) discrepancy at 11-14 weeks of gestation in twin pregnancies from an unselected population.

METHODS

This was a retrospective analysis of all twin pregnancies that underwent a routine 11-14-week scan at a large teaching hospital. Fetal loss was defined as fetal demise of one or both twins after 14 weeks.

RESULTS

A total of 507 twin pregnancies were studied; 382 (75.3%) were dichorionic and 125 (24.7%) were monochorionic twins. The discrepancy in CRL was expressed as a percentage of the CRL of the larger twin. The 95(th) and 99(th) centile for CRL discrepancy in twins was 12.2% and 19.3%, respectively. The discrepancy in CRLs in monochorionic and dichorionic twins was not significantly different (Mann-Whitney U = 22,406, P = 0.302). In 39 twin pairs, there was subsequent intrauterine death of one or both twins. Fetal loss was more common in monochorionic twins (24/125) than in dichorionic twins (15/382) (chi-square = 30.9, P < 0.001). In monochorionic twins, the discrepancy in CRLs in the 24 cases with subsequent loss was significantly greater than in the 101 twin pairs with no subsequent loss (Mann-Whitney U = 896, P = 0.048). The discrepancy in CRLs in 15 dichorionic twins with subsequent loss was not different from that in the 367 twins with no loss (Mann-Whitney U = 2116.5, P = 0.129). The CRL discrepancy was significantly correlated with birth-weight discordance in twins (Spearman's rho = 0.128, P = 0.006). However, this was due to a significant correlation in dichorionic twins (Spearman's rho = 0.127, P = 0.016) but not in monochorionic twins (Spearman's rho = 0.145, P = 0.14).

CONCLUSIONS

Fetal loss is significantly associated with discrepancy in CRL at the 11-14-week scan in monochorionic twins and discordance in birth weights is significantly associated with discrepancy in CRL in dichorionic twins. However, intertwin CRL discrepancy is of limited value in screening for these adverse events.

Twin-to-twin transfusion syndrome: a comprehensive update

Twin-to-twin transfusion syndrome (TTTS) is a serious complication in about 10% to 20% of monozygous twin gestations with an incidence of 4% to 35% in the United States. Severe TTTS is reported to occur in 5.5% to 17.5% of cases. TTTS is a progressive disease in which sudden deteriorations in clinical status can occur, leading to death of a co-twin. Up to 30% of survivors may have abnormal neurodevelopment as a result of the combination of profound antenatal insult and the complications of severe prematurity. This article presents an overview of what is known about the pathophysiology and the diagnosis of TTTS, the role of echocardiography in TTTS, treatment options available for TTTS, complications of treatment for TTTS, and short- and long-term outcomes of TTTS.

An embolic complication in a donor twin with severe twin-twin transfusion syndrome after fetoscopic intervention

Necrotic injury of an extremity in a donor twin is a rare complication of twin-twin transfusion syndrome after selective fetoscopic laser photocoagulation. We present the case of a 20-year-old gravida 2, para 1 with a twin gestation with severe twin-twin transfusion syndrome (Quintero Stage 3B) who had treatment with selective fetoscopic laser photocoagulation. Selective fetoscopic laser photocoagulation may be associated with extremity necrosis in a donor twin.

Selective fetoscopic laser photocoagulation of superficial placental anastomoses for the treatment of severe twin-twin transfusion syndrome

OBJECTIVE

To report our initial institutional experience with fetoscopic laser photocoagulation of placental anastomoses in severe twin-twin transfusion syndrome using a 1.0 mm endoscope.

METHODS

Between July 2006 and June 2008, 19 monochorionic diamniotic twin pregnancies complicated by severe TTTS (Quintero stages III and IV) underwent fetoscopic laser therapy. Perinatal data were prospectively collected and compared according to the Quintero stages.

RESULTS

Nine patients were classified as stage III and ten as stage IV. The Mean gestational ages at diagnosis and procedure were 20 (range: 17-25) and 22.0 (range: 19.0-26.0) weeks, respectively, with no statistical difference between the two groups. Preterm premature rupture of the membranes occurred in two cases (10.5%), and spontaneous preterm delivery in eight (42.1%). Overall mean gestational age at delivery was 32.1 (range: 26.0-38.0) weeks. Prematurity was more severe in stage IV patients (p<0.01). Among all cases, the overall survival rate was 52.6%, and the percentages of pregnancies with survival of both babies and at least one twin were 26.3% and 78.9%, respectively. In the case of stage III patients, the overall survival rate was 61.1%. Of the stage III pregnancies, 33.3% resulted in both babies surviving, and 88.9% of these pregnancies resulted in at least one surviving twin. For stage IV, as the corresponding statistics were 45.0%, 20.0% and 70.0% respectively.

CONCLUSIONS

Our initial institutional experience with 1.0 mm fetoscopic laser therapy for severe TTTS showed results similar to those reported in the literature for larger endoscopes.

Interventions for twin-twin transfusion syndrome: a Cochrane review

We performed a Cochrane review to assess which of the treatments for twin-twin transfusion syndrome (TTTS) improves fetal, childhood and maternal outcomes. This article represents a version of the review which includes additional data to the published version. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2007) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, October 2007) for randomized and quasi-randomized studies of amnioreduction, laser coagulation and septostomy and compared their outcomes. We also searched conference proceedings and contacted the authors of published trials for clarification and additional data. No trials compared intervention with no intervention. Three studies (253 women) were included. Laser coagulation resulted in less overall death (48% vs. 59%; relative risk (RR), 0.81; 95% CI, 0.65-1.01 adjusted for clustering; two trials, 364 fetuses), perinatal death (26% vs. 44%; RR, 0.59; 95% CI, 0.40-0.87 adjusted for clustering; one trial, 284 fetuses) and neonatal death (8% vs. 26%; RR, 0.29; 95% CI, 0.14-0.61 adjusted for clustering; one trial, 284 fetuses) when compared with amnioreduction. There was no difference in perinatal outcome between amnioreduction and septostomy. More babies were alive without neurological abnormality at the age of 6 months in the laser group than in the amnioreduction group (52% vs. 31%; RR, 1.66; 95% CI, 1.17-2.35 adjusted for clustering; one trial). There was no difference in the proportion of babies alive at 6 months that had undergone treatment for major neurological abnormality between the laser coagulation and the amnioreduction groups (4% vs. 7%; RR, 0.58; 95% CI, 0.18-1.86 adjusted for clustering; one trial). The results suggest that endoscopic laser coagulation of anastomotic vessels should be considered in the treatment of all stages of TTTS to improve perinatal and neonatal outcome.

Interventions for the treatment of twin-twin transfusion syndrome

BACKGROUND

Twin-twin transfusion syndrome, a condition affecting monochorionic twin pregnancies, is associated with a high risk of perinatal mortality and morbidity. A number of treatments have been introduced to treat the condition but it is unclear which intervention improves maternal and fetal outcome.

OBJECTIVES

The objective of this review was to evaluate the impact of treatment modalities in twin-twin transfusion syndrome.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (October 2007) and the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 4). We also searched conference proceedings and made personal contact with experts active in the area of the review.

SELECTION CRITERIA

Randomised and quasi-randomised studies of amnioreduction versus laser coagulation, septostomy versus laser coagulation or septostomy versus amnioreduction.

DATA COLLECTION AND ANALYSIS

One review author assessed eligibility and extracted data, which were checked by a second author. We contacted study authors for additional information.

MAIN RESULTS

Two studies (213 women) were included. This review shows that laser coagulation of anastomotic vessels results in less death of both infants per pregnancy (relative risk (RR) 0.33; 95% confidence interval (CI) 0.16 to 0.67, one trial), less perinatal death (RR 0.59; 95% CI 0.0.40 to 0.87 adjusted for cluster, one trial) and less neonatal death (RR 0.29; 95% CI 0.14 to 0.61 adjusted for cluster, one trial) than in pregnancies treated with amnioreduction. There is no difference in perinatal outcome between amnioreduction and septostomy. A third study is awaiting assessment. More babies were alive without neurological abnormality at the age of six months in the laser group than the amnioreduction groups (RR 1.66; 95% CI 1.17 to 2.35 adjusted for clustering, one trial). This difference did not persist beyond six months of age. There was no significant difference in the babies alive at six months with neurological abnormality treated by laser coagulation or amnioreduction (RR 0.58; 95% CI 0.18 to 1.86 adjusted for clustering, one trial).

AUTHORS' CONCLUSIONS

Endoscopic laser coagulation of anastomotic vessels should be considered in the treatment of all stages of twin-twin transfusion syndrome to improve perinatal outcome. Further research on the effect of treatment on milder forms of twin-twin transfusion syndrome (Quintero stage 1 and 2) are required. The long-term outcomes of survivors from the studies included in this review are required.