Management of fetofetal transfusion syndrome

Incidence and outcome of prenatal brain abnormality in twin-to-twin transfusion syndrome: systematic review and meta-analysis

OBJECTIVES

To evaluate the incidence of antenatally diagnosed brain injury in twin pregnancy complicated by twin-to-twin transfusion syndrome (TTTS) and to quantify the perinatal mortality, morbidity and long-term neurodevelopmental outcome of these fetuses.

METHODS

MEDLINE, EMBASE, ClinicalTrials.gov and The Cochrane Library databases were searched. Inclusion criteria were studies reporting on brain abnormality diagnosed antenatally in twin pregnancies complicated by TTTS. The primary outcome was the incidence of prenatal brain abnormality. The secondary outcomes were intrauterine demise (IUD), neonatal death, termination of pregnancy (TOP) and long-term morbidity. Outcomes were explored in the population of fetuses with antenatal diagnosis of brain abnormality. Subgroup analysis according to the type of treatment, gestational age, Quintero stage at diagnosis and/or treatment, and cotwin death was planned. Meta-analysis of proportions was used to combine data and pooled proportions and their 95% CI were reported.

RESULTS

Thirteen studies including 1573 cases of TTTS and 88 fetuses with an antenatal diagnosis of brain abnormality were included in the systematic review. The meta-analysis included only studies reporting on brain abnormality in twin pregnancy complicated by TTTS cases and treated with laser surgery. Overall, brain injury occurred in 2.2% (52/2410) of fetuses (eight studies). Brain abnormality was reported in 1.03% and 0.82% of recipients and donors, respectively. The most common type of abnormality was ischemic lesions (30.4% (95% CI, 19.1-43.0%)), followed by destructive lesions (23.9% (95% CI, 13.7-35.9%)), ventriculomegaly (19.9% (95% CI, 10.6-31.3%)) and hemorrhagic lesions (15.3% (95% CI, 7.1-25.8%)). Spontaneous IUD occurred in 13.4% (95% CI, 5.1-24.8%) of fetuses, while TOP was chosen by parents in 53.5% (95% CI, 38.9-67.8%) cases. Neonatal death was reported by only three studies, with an incidence of 15.4% (95% CI, 2.8-35.4%). Finally, only two studies reported on composite morbidity, with an overall rate of the outcome of 20.4% (95% CI, 2.5-49.4%) and rates of 29.7% and 20.4% in the recipient and donor fetuses, respectively. Due to the small numbers, only composite morbidity was analyzed and no information on neonatal intensive care unit admission, respiratory distress syndrome or other long-term outcomes, such as neurodevelopmental delay and cerebral palsy, could be retrieved reliably.

CONCLUSIONS

The overall incidence of antenatally diagnosed fetal brain abnormality in twin pregnancy complicated by TTTS treated with laser surgery is around 2% and is mainly ischemic in nature (30.4%). TOP was chosen by parents in more than half of cases (53.5%). No information could be retrieved on morbidity outcomes, highlighting the urgent need for long-term follow-up studies of these children. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

[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.

Operator competence in fetoscopic laser surgery for twin-twin transfusion syndrome: validation of a procedure-specific evaluation tool

OBJECTIVES

Fetoscopic laser surgery for twin-twin transfusion syndrome is a procedure for which no objective tools exist to assess technical skills. To ensure that future fetal surgeons reach competence prior to performing the procedure unsupervised, we developed a performance assessment tool. The aim of this study was to validate this assessment tool for reliability and construct validity.

METHODS

We made use of a procedure-specific evaluation instrument containing all essential steps of the fetoscopic laser procedure, which was previously created using Delphi methodology. Eleven experts and 13 novices from three fetal medicine centers performed the procedure on the same simulator. Two independent observers assessed each surgery using the instrument (maximum score: 52). Interobserver reliability was assessed using Spearman correlation. We compared the performance of novices and experts to assess construct validity.

RESULTS

The interobserver reliability was high (Rs  = 0.974, P < 0.001). Checklist scores for experts and novices were significantly different; the median score for novices was 28/52 (54%), whereas that for experts was 47.5/52 (91%) (P < 0.001). The procedure time and fetoscopy time were significantly shorter (P < 0.001) for experts. Residual anastomoses were found in 1/11 (9%) procedures performed by experts and in 9/13 (69%) procedures performed by novices (P = 0.005). Multivariable analysis showed that the checklist score, independent of age and gender, predicted competence.

CONCLUSIONS

The procedure-specific assessment tool for fetoscopic laser surgery shows good interobserver reliability and discriminates experts from novices. This instrument may therefore be a useful tool in the training curriculum for fetal surgeons. Further intervention studies with reassessment before and after training may increase the construct validity of the tool. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Differences between selective termination of pregnancy and fetal reduction in multiple pregnancy: a narrative review

Although selective termination of pregnancy and fetal reduction in multiple pregnancy both involve the termination in utero of the development of live fetuses, these two procedures are different in several aspects. Nevertheless, several authors tend to amalgamate and confuse their psychosocial consequences and the ethical issues they raise. Therefore, this narrative review, derived from a comparative analysis of 91 articles, shines a light on these amalgamations and confusions, as well as on the medical, contextual, experiential and ethical differences specific to selective termination and fetal reduction.

Establishing a national program for fetoscopic guided laser occlusion for twin-to-twin transfusion syndrome in Sweden

OBJECTIVE

To describe the establishment of the fetoscopic guided laser occlusion (FLOC) technique for treatment of twin-to-twin transfusion syndrome (TTTS) and the initial results in a Swedish national center.

DESIGN

Retrospective, descriptive study.

SETTING

Tertiary level university hospital.

POPULATION

All referred and treated cases suffering significant TTTS.

METHODS

The present study includes all cases of FLOC for TTTS at the Center of Fetal Medicine at Karolinska University Hospital, Stockholm, Sweden from October 2001 until December 2009. Patients were referred from all over Sweden and a few from other Nordic countries. The patients were evaluated with ultrasound examination between gestational ages of 18 and 26 weeks. Data from patients were extracted from our electronic medical record system and, in addition, families were contacted and medical records requested from referring hospitals.

MAIN OUTCOME MEASURES

Pregnancies with one or more surviving infants after FLOC treatment categorized according to stage of TTTS.

RESULTS

In 75% of pregnancies, one or more infant was born alive. At stage I, both infants survived in one pregnancy and one survived in the second. There was no significant difference between cases at stage II or III, i.e. 73 vs. 78% of pregnancies resulted in one or more surviving infant. At stage IV, 66% of pregnancies ended with one or more surviving infant.

CONCLUSIONS

Treatment of TTTS is feasible in a rather small country like Sweden, with comparable results to other centers. There are strong arguments for centralization and further improvement of this kind of highly specialized treatment.

[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.

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.

Pseudoamniotic band syndrome: a rare complication of monochorionic twins with fetofetal transfusion syndrome treated by laser coagulation

OBJECTIVE

The purpose of this study was to assess the incidence and risk factors of limb constriction defects that are related to pseudoamniotic band syndrome (PABS) after selective fetoscopic laser surgery (FLS) in fetofetal transfusion syndrome (FFTS).

STUDY DESIGN

All consecutive cases of FFTS that were treated by selective FLS between 1999 and 2006 were examined prospectively for PABS at the time of delivery. Incidence and characteristics of PABS were reported. Univariate analysis was conducted to look for potential risk factors of developing PABS.

RESULTS

The 438 consecutive FFTS cases were treated at 15-26 weeks of gestation; PABS developed in 8 cases (1.8 %). The affected twin was always the former recipient. The diagnosis was made prenatally in 2 of 8 cases (25%). All cases survived the perinatal period. PABS affected fetal leg, arm, and foot in 3, 4, and 1 cases, respectively. In 5 (62.5%) and 7 (87.5%) cases, PABS occurred after premature rupture of membranes and intrauterine death of the donor, respectively. In 4 cases (50%), there was both premature rupture of membranes (PROM) and intrauterine fetal death; in 3 cases (37.5%), there was intrauterine fetal death alone, and in 1 case (12.5%), there was PROM alone. In the remaining 430 cases, PROM occurred in 62 cases (14.4%) and 66 cases (15.3%) within and after 3 weeks after surgery, respectively. PROM was significantly more frequent within the group that was complicated with PABS than within the rest of the cohort (P = .05). No maternal, fetal, or perioperative risk factor could be identified.

CONCLUSION

Awareness and targeted serial ultrasound evaluation in this high-risk group may improve prenatal diagnosis, counseling, and management of PABS after FLS.

A definition of selectivity in laser coagulation of chorionic plate anastomoses in twin-to-twin transfusion syndrome and its relationship to perinatal outcome

OBJECTIVE

This study was undertaken to correlate selectivity of surgery and perinatal outcome in twin-to-twin transfusion syndrome treated by endoscopic laser coagulation, using a quantitative definition of selectivity.

STUDY DESIGN

287 consecutive cases of severe twin-to-twin transfusion syndrome were reviewed. A selectivity index was built as the ratio of selective over nonselective coagulations per procedure. Outcome measures were survival at 28 days and failure of surgery as defined by recurrence of twin-to-twin transfusion syndrome or fetofetal hemorrhage.

RESULTS

Two populations were identified: a high selectivity group (63.8%) and a low selectivity group (36.2%). Survival of at least one twin and survival of both twins were higher in the high-selectivity group (p = .007 and p = .04 respectively). Failure of surgery rates were similar in both groups.

CONCLUSION

A quantitative definition of selectivity appears justified by the large variations found in the practice of a single center and by significant differences in outcome. Survival is significantly improved in highly selective procedures.

Stage I twin-twin transfusion syndrome: rates of progression and regression in relation to outcome

OBJECTIVES

Twin-twin transfusion syndrome (TTTS) results in high rates of perinatal mortality and neurological morbidity. Fetoscopic laser ablation of placental anastomoses is now established as the treatment of choice for advanced disease. However, there remains controversy about its use in early-stage TTTS, in which laser-related fetal losses need to be balanced against relatively favorable outcomes with more conservative approaches. We investigated rates of progression and regression in Stage I TTTS and determined factors influencing the course of the disease.

METHODS

We undertook a retrospective observational study of all TTTS cases referred to our tertiary referral fetal medicine service from 2000 to 2006. In patients presenting with Stage I TTTS, the following variables were evaluated for their ability to predict the course and progression of the disease: gestational age (GA) at presentation, amniotic fluid index, recipient and donor deepest vertical pool, presence of artery-artery anastomoses, small-sized bladder compared to normal donor bladder and fetal size discordance. Study end-points were disease regression or progression, and neonatal survival at 28 days.

RESULTS

Among 132 consecutive cases of TTTS, 46 women presented with Stage I disease. In the majority (69.6%), disease remained stable (28.3%) or regressed (41.3%). Of cases that progressed, 79% did so within 2 weeks and 93% progressed to at least Stage III. No factor was significantly linked with progression or regression, although there was a trend towards the absence of an artery-artery anastomosis (P = 0.10) and the presence of a small rather than normal donor bladder (P = 0.10) influencing progression, and later GA at presentation (P = 0.07) influencing regression. At least one infant survived in 83% of cases and there was double survival in 59%. Perinatal outcome was significantly better in cases that regressed (the rates of at least one survivor and double survival being 89% and 89%, respectively) or remained Stage I (77% and 61%, respectively), compared with those cases that progressed (79% and 14%, respectively). Treatment with amnioreduction at first presentation did not influence progression or regression.

CONCLUSIONS

This study demonstrates that a high percentage of Stage I TTTS cases regress or remain early stage. Identification of factors predicting progression would facilitate the selection of patients for definitive therapy, while avoiding treatment-related morbidities in mild or transient disease.

Neonatal outcome in preterm monochorionic twins with twin-to-twin transfusion syndrome after intrauterine treatment with amnioreduction or fetoscopic laser surgery: comparison with dichorionic twins

OBJECTIVE

The purpose of this study was to compare neonatal outcome in preterm neonates after twin-to-twin transfusion syndrome (TTTS) that was treated by amnioreduction or fetoscopic laser surgery (FLS) and in dichorionic neonates who were matched for gestational age at birth.

STUDY DESIGN

Neonatal outcome was assessed in 137 TTTS preterm neonates who were treated primarily with either amnioreduction (n = 36) or FLS (n = 101) and compared with dichorionic twins (n = 242) who were delivered at our center at 24-34 weeks of gestation.

RESULTS

Adverse neonatal outcome (death or severe cerebral lesions) was more frequent in the amnioreduction group than in the FLS and dichorionic groups. Overall neonatal outcome was comparable in FLS and dichorionic infants. However, neonatal morbidity was higher in FLS neonates at <30 weeks of gestation that was related mainly to failed laser therapy.

CONCLUSION

In preterm TTTS cases, neonatal morbidity decreases independently with gestational age and after successful FLS. Neonatal morbidity that was specific of TTTS was higher in the amnioreduction group and in cases with failed laser therapy.

Fetoscopic laser therapy for twin-twin transfusion syndrome

Twin-twin transfusion syndrome (TTTS) complicates approximately 1 in 5 of all monochorionic, diamniotic twin pregnancies. If of early onset and untreated, severe TTTS is associated with a dismal prognosis, with perinatal mortality rates exceeding 90%. The most controversial issue regarding the optimal treatment of TTTS has centered on the use of amniocentesis or laser until the first and only randomized trial on interventions for TTTS was published a couple of years ago, comparing laser to amnioreduction. That report confirmed that the laser group had a higher likelihood of the survival of at least one twin to 28 days of age and to 6 months of age. Infants in the laser group also had a lower incidence of cystic periventricular leukomalacia and were more likely to be free of neurologic complications at 6 months of age (52% vs. 31%, p = 0.003). Although not every case of TTTS is an eligible candidate for fetoscopic-guided laser therapy, it is recommended that obstetricians who have the chance to manage TTTS in their daily practice be familiar with the rationale behind this laser treatment for TTTS.

Twin-twin transfusion syndrome: where do we go from here?

Management of Twin-Twin Transfusion Syndrome (TTTS) is one of the most challenging clinical problems concerning multiple gestations. The pathophysiology of TTTS and Quintero staging system are described. The importance of fetal echocardiograms in assessing prognosis and response to therapy is highlighted. Treatment modalities, particularly amnioreduction, microseptostomy, and fetoscopic laser photocoagulation, are discussed. Questions still remain as to how various treatment options affect short- and long-term cardiac and neurodevelopmental outcomes and which patients will benefit most from selective laser photocoagulation therapy.