Fetoscopic laser coagulation in 1020 pregnancies with twin-twin transfusion syndrome demonstrates improvement in double-twin survival rate

Fetoscopic laser coagulation for twin-to-twin transfusion syndrome: a comparison of flexible 1.0/1.2 mm fetoscopes with curved sheaths of 2.7/3.3 mm2 vs. 2 mm fetoscopic lens technique with sheaths of 6.6/11.3 mm2

OBJECTIVES

Fetoscopic laser coagulation of placental anastomoses is usually performed for a treatment of twin-to-twin transfusion syndrome (TTTS). A common complication of fetoscopic laser coagulation for TTTS is preterm preliminary rupture of fetal membranes (PPROM) aggravating the neonatal outcome significantly. However, use of an flexible 1 mm fetoscope with an curved sheath could reduce iatrogenic damage of the amniotic membrane and improve neonatal outcomes after laser treatment. The aim of this study was to compare neonatal outcomes using this flexible fetoscope with curved sheath vs. use of a standard lens technique.

METHODS

Outcomes were retrospective analyzed after use of a standard lens fetoscope of 2 mm (sheath 6.63 mm2 or 11.27 mm2 for anterior placenta) and a flexible fetoscope of 1 mm or 1.2 mm (sheath 2.65 mm2 or 3.34 mm2) in two German centers of fetal surgery, performed during 2006-2019.

RESULTS

Neonatal outcome of 247 TTTS patients were analyzed including the rates of double and single fetal survival. The survival of at least one fetus was 97.2 % in the group with the ultrathin technique (n=154) compared to 88.3 % (n=93) in the group with the standard lens fetoscope (p=0.008). Survival of both fetuses was not different between groups (81.0 vs. 75.3 %). The procedure to delivery interval was significantly increased using the ultrathin fetoscope (89.1±35.0 d vs. 71.4±35.4 d, p=0.001) resulting in an increased gestational age at delivery by 11 days on average (231.9±28.1 d vs. 221.1±32.7 d, p=0.012).

CONCLUSIONS

Fetal survival can be significantly increased following TTTS using flexible fetoscope of 1 mm or 1.2 mm (sheath 2.65 mm2 or 3.34 mm2).

Fetoscopic laser versus amnioreduction, septostomy, and expected management for the treatment of twin-twin transfusion syndrome (TTTS): an economic evaluation analysis in Iran

BACKGROUND

Twin-twin transfusion syndrome (TTTS) affects 10-15% of monochorionic twin pregnancies. Without treatment, their mortality rates would be considerable. There are differences in survival rate between different therapeutic modalities. This study aims to compare the cost-effectiveness of Fetoscopic laser versus amnioreduction, septostomy, and expected management in the treatment of twin-to-twin transfusion syndrome (TTTS).

METHODS

This is a cost-effectiveness analysis of the treatment strategies in patients with TTTS. A decision tree model was used to estimate the clinical and economic outcomes with a pregnancy period time horizon. Medical direct costs were extracted in a quantitative study, and survival rates were determined as effectiveness measures based on a review. A probabilistic sensitivity analysis was used to measure the effects of uncertainty in the model parameters. The TreeAge, Excel and R software were used for analyzing data.

RESULTS

In the first phase, 75 studies were included in the review. Based on the meta-analysis, a total of 7183 women treated with Fetoscopic laser, the perinatal survival of at least one twin-based pregnancy was 69%. In the second phase, the results showed that expected management and amnioreduction have the lowest (791.6$) and highest cost (2020.8$), respectively. Based on the decision model analysis, expected management had the lowest cost ($791.67) and the highest rate in at least one survival (89%), it was used only in early stages of TTTS. Fetoscopic laser surgery, with the mean cost 871.46$ and an overall survival rate of 0.69 considered the most cost-effectiveness strategy in other stages of TTTS.

CONCLUSION

Our model found Fetoscopic laser surgery in all stages of TTTS to be the most cost-effective therapy for patients with TTTS. Fetoscopic laser surgery thus should be considered a reasonable treatment option for TTTS.

Perinatal outcomes following fetoscopic laser surgery for early twin-to-twin transfusion syndrome: Systematic review and meta-analysis

INTRODUCTION

Our objective was to investigate outcomes in twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic laser surgery (FLS) at <18 weeks vs ≥18 weeks, and to conduct subgroup analysis of TTTS with FLS at <16 weeks vs 16-18 weeks.

MATERIAL AND METHODS

PubMed, Scopus and Web of Science were searched systematically from inception until May 2023. Primary outcome was survival, and secondary outcomes included preterm premature rupture of membranes (PPROM), preterm birth and gestational age (GA) at delivery.

RESULTS

Nine studies encompassing 1691 TTTS pregnancies were included. TTTS stage III was significantly more common in TTTS pregnancies treated with FLS at <18 weeks (odds ratio [OR] 2.84, 95% confidence interval [CI] 1.24-6.54), and procedure duration was shorter at <18 weeks (MD -5.27 minutes, 95% CI -9.19 to -1.34). GA at delivery was significantly earlier in TTTS pregnancies treated with FLS at <18 weeks (MD -3.12 weeks, 95% CI -6.11 to -0.13). There were no significant differences in outcomes, including PPROM, PPROM at <7 days post-FLS, preterm birth at <28 and <32 weeks, delivery at <7 days post-FLS, and survival outcomes, including fetal demise, live birth and neonatal survival. Similarly, TTTS stage III was more common in TTTS with FLS at <16 weeks than at 16-18 weeks (OR 2.95, 95% CI 1.62-5.35), with no significant differences in the aforementioned outcomes.

CONCLUSIONS

In early TTTS treated with FLS, outcomes were comparable between those treated at <18 weeks compared with ≥18 weeks except for GA at delivery, which was 3 weeks earlier. In the subset treated at <16 weeks vs 16-18 weeks, the procedure was feasible without an increased risk of very early preterm birth or perinatal mortality.

The Outcome after Laser Therapy of Monochorionic Twin Pregnancies Complicated by Twin-Twin Transfusion Syndrome with Coexistent Selective Fetal Growth Restriction

Background: Most previous studies evaluated outcomes of twin-twin transfusion syndrome (TTTS) without considering the coexistence of selective fetal growth restriction (sFGR). The objectives of this study were to compare twin survival and pregnancy complications after laser therapy of TTTS with and without sFGR. Methods: For this purpose, a retrospective cohort study including 98 monochorionic diamniotic twins and three dichorionic triamniotic triplets treated in a single tertiary center was conducted. Results: Overall, 46 twins had selective fetal growth restriction (26 type I, 13 type II, 7 type III). At birth, donor survival (61% vs. 91%), double survival (57% vs. 82%), and overall survival (75% vs. 88%) were significantly lower in the group with coexistent sFGR. Recipient survival (89% vs. 86%), miscarriage (7% vs. 2%), PPROM < 32 weeks (48% vs. 29%), and preterm delivery < 32 weeks (52% vs. 45%) were not significantly higher in the group with coexistent sFGR. Donor twins with sFGR type I (69% vs. 91%) and types II-III (50% vs. 91%) showed significantly lower survival than those without sFGR. Multivariate regression analysis identified sFGR and its subtypes as independent predictors of donor demise. Conclusions: the coexistence of sFGR in TTTS pregnancies was associated with poor donor outcomes and is probably the most important predictor of donor survival.

Feasibility of continuous intra-uterine pressure measurements during amnioreduction in twin-to-twin transfusion syndrome therapy

INTRODUCTION

This work explores the feasibility of simultaneous and continuous intra-abdominal, intra-uterine, and arterial blood pressure measurements to examine the hemodynamic perturbation expected during therapeutic amnioreduction and to better understand the protective role of the placenta during that treatment.

METHODS

Patients with twin-to-twin transfusion syndrome were treated with fetoscopic laser ablation followed by amnioreduction. Intra-abdominal, intra-uterine, and mean arterial pressures were simultaneously recorded during amnioreduction performed in steps of 200 mL. Placental thickness and uterine dimensions were measured before and after amnioreduction by ultrasonography.

RESULTS

Useful pressure recordings were obtained between volume reduction steps and short hands-off periods in four studies. Median amnioreduction volume was 1400 mL corresponding to a median uterine volume reduction of 1121 mL. Mean intra-uterine pressure significantly fell from 24.8 to 13.6 mmHg (p = 0.011) and intra-abdominal pressure significantly decreased from 13.4 to 9.2 mmHg after amnioreduction (p = 0.015). Uterine pressure recordings revealed transient contractions (A, in mmHg) following individual amnioreduction steps, which increased with fractional amnioreduction (F, no dimension) (A = 17.23*F + 11.81; r = 0.50, p = 0.001).

DISCUSSION

Simultaneous and continuous measurement of intra-abdominal, intra-uterine, and arterial blood pressures during amnioreduction is feasible. The dynamics reveal transient uterine contractions reaching levels comparable to those seen during childbirth which seem to oppose impending maternal hypovolemia by placental steal at the expense of temporarily reducing placental perfusion pressure and underline the importance of uterine and placental interaction.

Factors influencing surgical performance and learning progress in minimally invasive surgery - results of an interdisciplinary multicenter study

BACKGROUND

Advancing surgical techniques require a high level of adaptation and learning skills on the part of surgeons. The authors need selection procedures and decision support systems for the recruitment of medical students and young surgeons. The authors aimed to investigate factors influencing the surgical performance and learning abilities of surgeons and medical students.

MATERIALS AND METHODS

The training scores of persons attending 16 standardized training courses (at three training centers) of the German Working Group for Gynecological Endoscopy (AGE e.V.) from 2017 to 2020, individual characteristics, and the results of psychomotor tests of three-dimensional imagination and hand-eye coordination were correlated. Similar analyses were performed for medical students in their final clinical year from 2019 to 2020. The training concept was evaluated in a prospective, multicenter, interdisciplinary, multinational setting.

RESULTS

In all, 180 of 206 physicians (response rate 87.4%) and 261 medical students (response rate 100%) completed the multistage training concept successfully. Of personal characteristics, the strongest correlation was noted for good surgical performance and learning success, and the absolute number of performed laparoscopic surgeries ( r =0.28-0.45, P <0.001/ r =0.1-0.28, P <0.05). A high score on the spatial visualization ability test was also correlated with good surgical performance ( r =0.18-0.27, P <0.01). Among medical students with no surgical experience, however, age was negatively correlated with surgical performance, that is the higher the age, the lower the surgical performance ( r =0.13/ r =0.22, P <0.05/ P <0.001).

CONCLUSION

Individual factors (e.g. surgical experience, self-assessment, spatial visualization ability, eye-hand coordination, age) influence surgical performance and learning. Further research will be needed to create better decision support systems and selection procedures for prospective physicians. The possibilities of surgical training should be improved, promoted, and made accessible to a maximum number of surgical trainees because individual learning curves can be overcome even by less talented surgeons. Training options should be institutionalized for those attending medical school.

Developmental outcomes for survivors of placental laser photocoagulation for the management of twin-to-twin transfusion syndrome

BACKGROUND

Fetoscopic laser coagulation of placental anastomoses reverses the pathological process in twin-to-twin transfusion syndrome, thereby increasing survival, but there are a paucity of studies addressing long-term neurodevelopmental outcome of survivors. This study aimed to ascertain the presence of neurodevelopmental disabilities in child survivors of monochorionic pregnancies managed by placental laser photocoagulation in the Australian state of Victoria.

METHODS

All pregnancies undergoing placental laser photocoagulation with the Victorian Fetal Therapy Service between 2006-2017 were included. Information on each surviving child, including demographics, perinatal course, and developmental progress was collected from parents, and consent was sought to complete the Child Behaviour Checklist. Interviewers evaluated whether this information was consistent with a diagnosis of any of 14 neurodevelopmental conditions. A three-tiered outcome measure was allocated for each child: (1) unimpaired or developmentally normal, (2) mild or moderate neurological impairment, or (3) severe neurological impairment. Clinical predictors for adverse outcome were identified.

RESULTS

Of 116 pregnancies (113 twin, 3 triplet), 96 (83%) resulted in 1 + surviving fetuses. 57/113 (50%) twin pregnancies resulted in 2 survivors, 36 (32%) in 1 survivor, and 20 (18%) in no survivors. Of the 235 fetuses, 154 (65.5%) survived to follow-up. Survival increased from 59% in 2006-2008 to 73% in 2015-2017. 90/154 (58%) survivors were followed up at a mean age of 7.5 [SD 3.0] years. Based on parental interview and Child Behaviour Checklist data, 28/90 (31%) participants were assessed as having neurodevelopmental impairment, 27 of mild-moderate severity and 1 severe. Speech/language disorders, attention deficit (hyperactivity) disorders, and fine motor impairment were most common. Neonatal length of stay conferred the highest risk of impairment.

CONCLUSION

Substantial variation exists between fetal therapy services in the type and length of neonatal follow-up following fetoscopic laser coagulation, contributing to a lack of data on long-term outcomes. The findings from this study support increasingly urgent calls to undertake systematic and sustained follow-up of fetoscopic laser coagulation survivors until school age. Information from this study may assist parents in their decision-making when offered fetal surgery. Importantly, it highlights a group for targeted surveillance and early intervention.

Intertwin Membrane Perforation and Umbilical Cord Entanglement after Laser Surgery for Twin-Twin Transfusion Syndrome: Prevalence, Risk Factors, and Outcome

INTRODUCTION

Perforation of the intertwin membrane can occur as a complication of fetoscopic laser surgery for twin-twin transfusion syndrome (TTTS). Data on the occurrence and the risk of subsequent cord entanglement are limited. The objective of this study was to assess the prevalence, risk factors and outcome of intertwin membrane perforation, and cord entanglement after laser surgery for TTTS.

METHODS

In this multicenter retrospective study, we included all TTTS pregnancies treated with laser surgery in two fetal therapy centers, Shanghai (China) and Leiden (the Netherlands) between 2002 and 2020. We evaluated the occurrence of intertwin membrane perforation and cord entanglement after laser, based on routine fortnightly ultrasound examination and investigated the risk factors and the association with adverse short- and long-term outcomes.

RESULTS

Perforation of the intertwin membrane occurred in 118 (16%) of the 761 TTTS pregnancies treated with laser surgery and was followed by cord entanglement in 21% (25/118). Perforation of the intertwin membrane was associated with higher laser power settings, 45.8 Watt versus 42.2 Watt (p = 0.029) and a second fetal surgery procedure 17% versus 6% (p < 0.001). The group with intertwin membrane perforation had a higher rate of caesarean section (77% vs. 31%, p < 0.001) and a lower gestational age at birth (30.7 vs. 33.3 weeks of gestation, p < 0.001) compared to the group with an intact intertwin membrane. Severe cerebral injury occurred more often in the group with intertwin membrane perforation, 9% (17/185) versus 5% (42/930), respectively (p = 0.019). Neurodevelopmental outcome at 2 years of age was similar between the groups with and without perforation of the intertwin membrane and between the subgroups with and without cord entanglement.

CONCLUSION

Perforation of the intertwin membrane after laser occurred in 16% of TTTS cases treated with laser and led to cord entanglement in at least 1 in 5 cases. Intertwin membrane perforation was associated with a lower gestational age at birth and a higher rate of severe cerebral injury in surviving neonates.

Prediction of dual survival following fetoscopic laser photocoagulation for twin-twin transfusion syndrome

OBJECTIVE

To develop a model based on factors available at the time of diagnosis of twin-twin transfusion syndrome (TTTS) for predicting the probability of dual twin survival following fetoscopic laser photocoagulation (FLP) using a machine-learning algorithm.

METHODS

This was a retrospective study of data collected at two university-affiliated tertiary fetal centers between 2012 and 2021. The cohort included monochorionic diamniotic twin pregnancies complicated by TTTS that underwent FLP. Data were stratified based on survival 30 days after delivery, and cases with dual survival were compared to those without dual survival. A random forest machine-learning algorithm was used to construct a prediction model, and the relative importance value was calculated for each parameter that presented a statistically significant difference between the two study groups and was included in the model. The holdout method was applied to check overfitting of the random forest algorithm. A prediction model for dual twin survival 30 days after delivery was presented based on the test set.

RESULTS

The study included 537 women with monochorionic diamniotic twin pregnancy, of whom 346 (64.4%) had dual twin survival at 30 days after delivery and were compared with 191 (35.6%) cases that had one or no survivors. Univariate analysis demonstrated no differences in demographic parameters between the groups. At the time of diagnosis, the dual-survival group had lower rates of estimated fetal weight (EFW) < 10th centile for gestational age in the donor twin (56.4% vs 69.4%; P = 0.004), intertwin EFW discordance > 25% (40.8% vs 56.5%; P = 0.001) and anterior placenta (40.5% vs 50.0%; P = 0.034). Comparison of Doppler findings between the two groups demonstrated significant differences in the donor twin, with a lower rate of pulsatility index (PI) > 95th centile in the umbilical artery and ductus venosus and a lower rate of PI < 5th centile in the fetal middle cerebral artery in the dual-survival group. Relative importance values for each of these six parameters were calculated, allowing the construction of a prediction model with an area under the receiver-operating-characteristics curve of 0.916 (95% CI, 0.887-0.946).

CONCLUSIONS

We developed a predictive model for dual survival in monochorionic twin pregnancies following FLP for TTTS, which incorporates six variables obtained at the time of diagnosis of TTTS, including donor EFW < 10th centile, intertwin EFW discordance > 25%, anterior placenta and abnormal PI in the umbilical artery, ductus venosus and middle cerebral artery of the donor twin. This clinically applicable tool may improve treatment planning and patient counseling. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Impact of middle cerebral artery pulsatility index on donor survival in twin-twin transfusion syndrome

OBJECTIVE

To assess outcomes in twin-twin transfusion syndrome (TTTS) according to middle cerebral artery pulsatility index (MCA-PI) prior to fetoscopic laser photocoagulation (FLPC) surgery.

METHODS

A retrospective cohort analysis of monochorionic-twin pregnancies complicated by TTTS who underwent FLPC at two fetal centers (2012-2021). The cohort was stratified according to abnormal MCA-PI of the donor twin, defined as below fifth centile for gestational age.

RESULTS

Abnormal MCA-PI of the donor twin was detected in 46 (17.7%) cases compared to 213 (83.3%) controls with no such abnormality. The abnormal PI group presented with higher rates of sFGR (56.5% vs. 36.8% in controls, p = 0.014) and lower donor survival rates within 48 h after FLPC (73.9 vs. 86.8%, p = 0.029). Donor twin survival rates at the time of delivery and 30 days after birth were lower in the abnormal MCA-PI. Multivariate logistic regression analysis controlling for sFGR and MCA-PI <fifth centile demonstrated the latter to be independently associated with lower survival rates at the time of delivery and 30 days after birth [OR = 0.497 95%CI (0.250-0.986) p = 0.045, and OR = 0.499 95%CI (0.252-0.986), p = 0.046, respectively]. Recipient's survival rates did not differ between the groups.

CONCLUSIONS

Donor survival at the time of delivery and 30 days after birth was lower in TTTS cases with MCA-PI<fifth centile for gestational age prior to laser surgery. This parameter may be considered when evaluating prognosis for TTTS.

The prevalence and associated factors of prenatal depression and anxiety in twin pregnancy: a cross-sectional study in Chongqing, China

Background

Pregnant women expecting twins are more likely to experience stress, which can lead to anxiety and depression. Our aim was to investigate the prevalence of prenatal anxiety and depressive symptoms in women with twin pregnancies and the associated factors.

Methods

In a cross-sectional survey, 210 women with twin pregnancies who satisfied the inclusion and exclusion criteria in two tertiary centers in Southwestern China were asked to complete a basic information form, the Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS). To compare statistics with normal distribution in distinct characteristic groups, a paired t-test, and one-way ANOVA were utilized. Binary logistic step regression was used to analyze the associated factors of antenatal anxiety and depressive symptoms.

Results

The 210 women with twin pregnancies (age = 30.8 ± 4.2 years) were between 7 and 37 gestational weeks (29.2 ± 1.2 weeks), were typically well-educated (72.4% had a post-high-school degree), and reasonably affluent (88.1% were above the low-income cutoff). Among them, 34.8% had symptoms associated with clinical levels of anxiety, and 37.1% had symptoms indicating possible depression. The prevalence of co-morbid anxiety and depressive symptoms was 24.3%. Binary stepwise logistic regression analysis showed that previous health status and sleep disturbance during pregnancy were the associated factors of anxiety symptoms in women with twin pregnancies (P < 0.05), whereas age, previous health status, negative life events, and physical activity during pregnancy were the associated factors of depressive symptoms in women with twin pregnancies (P < 0.05).

Conclusion

About one-third of women with twin pregnancies had symptoms of anxiety or depression; these were most strongly predicted by some modifiable factors, suggesting that early preventive mind-body interventions may be a promising strategy to protect against mental health issues for women with twin pregnancies.

Molecular Mechanisms Underlying Twin-to-Twin Transfusion Syndrome

Twin-to-twin transfusion syndrome is a unique disease and a serious complication occurring in 10–15% of monochorionic multiple pregnancies with various placental complications, including hypoxia, anemia, increased oxidative stress, and ischemia-reperfusion injury. Fetoscopic laser photocoagulation, a minimally invasive surgical procedure, seals the placental vascular anastomoses between twins and dramatically improves the survival rates in twin-to-twin transfusion syndrome. However, fetal demise still occurs, suggesting the presence of causes other than placental vascular anastomoses. Placental insufficiency is considered as the main cause of fetal demise in such cases; however, little is known about its underlying molecular mechanisms. Indeed, the further association of the pathogenic mechanisms involved in twin-to-twin transfusion syndrome placenta with several molecules and pathways, such as vascular endothelial growth factor and the renin–angiotensin system, makes it difficult to understand the underlying pathological conditions. Currently, there are no effective strategies focusing on these mechanisms in clinical practice. Certain types of cell death due to oxidative stress might be occurring in the placenta, and elucidation of the molecular mechanism underlying this cell death can help manage and prevent it. This review reports on the molecular mechanisms underlying the development of twin-to-twin transfusion syndrome for effective management and prevention of fetal demise after fetoscopic laser photocoagulation.

Relationship Between the Types and Diameters of Residual Vessels and Secondary TAPS after Fetoscopic Laser Surgery for TTTS

Objective This study aimed to investigate the relationship between the characteristics and diameters of residual anastomoses and the occurrence of twin anemia-polycythemia sequence (TAPS) in twin-to-twin transfusion syndrome (TTTS) patients with placental vascular injection after fetoscopic laser surgery (FLS).

Methods A total of 90 cases of pregnant women who underwent FLS owing to TTTS were collected in the university hospital from May 2018 to December 2020. Therein, 40 cases received placental injection and were divided into the TAPS group and non-TAPS group according to the postoperative complications. The number of residual superficial anastomoses was counted and the diameter was measured.

Results Among the placentae of nine patients in the TAPS group, two cases had no superficial anastomoses, and seven cases had 16 superficial anastomoses, including eight arterio-venous (AV) anastomoses, two veno-arterial (VA) anastomoses, three arterio-arterial (AA) anastomoses and three veno-venous (VV) anastomoses. Among the placentae of 31 patients in the non-TAPS group, 19 cases had no superficial anastomoses, and 12 cases had 18 superficial anastomoses, including two AV anastomoses, five VA anastomoses, seven AA anastomoses, and four VV anastomoses; and both the two cases of AV anastomoses were accompanied by AA anastomoses. The number of AV anastomoses in the placentae of the TAPS group was significantly elevated compared with that in the non-TAPS group (p<0.05). While there was no significant difference in the numbers of placentae with superficial anastomoses, the numbers of blood vessels with VA anastomoses, VV anastomoses, and AA anastomoses between the two groups (p>0.05). Through analyzing the diameters of 34 superficial anastomoses in the two groups, it was shown that the diameters of AA anastomoses in the non-TAPS group were significantly larger than those in the TAPS group (Z=1.97, p<0.05). There was no statistical difference in the diameters of AV anastomoses (Z=0.52, p>0.05), VA anastomoses (Z=0.98, p>0.05), and VV anastomoses (Z=0.36, p>0.05). The differences of the birth weight and inter-twin hemoglobin difference were statistically significant (p<0.05). The result indicated that the differences between age, gestational weeks at operation, delivery, and mean operating times were not statistically significant (p>0.05).

Conclusion The increase in the number of AV anastomoses could obviously elevate the incidence of TAPS. The probability of TAPS occurrence is reduced following the increased diameters of AA anastomoses, demonstrating that AA anastomosis has a protective effect on TTTS patients.

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.

Comprehensive Metabolomic Profiling of Cord Blood and Placental Tissue in Surviving Monochorionic Twins Complicated by Twin-Twin Transfusion Syndrome With or Without Fetoscopic Laser Coagulation Surgery: A Retrospective Cohort Study

Objectives: To investigate metabolomic perturbations caused by twin-twin transfusion syndrome, metabolic changes associated with fetoscopic laser coagulation in both placental tissue and cord plasma, and to investigate differential metabolites pertinent to varying fetal outcomes, including hemodynamic status, birth weight, and cardiac function, of live-born babies.

Methods: Placental tissue and cord plasma samples from normal term or uncomplicated preterm-born monochorionic twins and those complicated by twin-twin transfusion syndrome treated with or without fetoscopic laser coagulation were analyzed by high-performance liquid chromatography metabolomic profiling. Sixteen comparisons of different co-twin groups were performed. Partial least squares–discriminant analysis, metabolic pathway analysis, biomarker analysis, and Spearman’s correlation analysis were conducted based on differential metabolites used to determine potential biomarkers in different comparisons and metabolites that are pertinent to neonatal birth weight and left ventricular ejection fraction.

Results: These metabolomic investigations showed that the cord plasma metabolome has a better performance in discriminating fetuses among different hemodynamic groups than placental tissue. The metabolic alteration of twin-twin transfusion syndrome in these two types of samples centers on fatty acid and lipid metabolism. The fetoscopic laser coagulation procedure improves the metabolomic change brought by this syndrome, making the metabolomes of the treated group less distinguishable from those of the control and preterm birth groups. Certain compounds, especially lipids and lipid-like molecules, are noted to be potential biomarkers of this morbid disease and pertinent to neonatal birth weight and ejection fraction.

Conclusions: Fetoscopic laser coagulation can ameliorate the metabolomic alteration caused by twin-twin transfusion syndrome in placental tissue and cord plasma, which are involved mainly in fatty acid and lipid-like molecule metabolism. Certain lipids and lipid-like molecules are helpful in differentiating co-twins of different hemodynamic statuses and are significantly correlated with neonatal birth weight or ejection fraction.

Management of atypical cases of twin-to-twin transfusion syndrome

Up to 20% of monochorionic diamniotic twin pregnancies can be complicated with twin-to-twin transfusion syndrome (TTTS). This complication is diagnosed by ultrasound demonstrating amniotic fluid discordance between both amniotic sacs, with polyhydramnios in the recipient's sac and oligohydramnios in the donor's, secondary to an imbalance in blood volume exchange between twins. Ultrasound evaluation of the amniotic fluid volume, bladder filling, and assessment of fetal Doppler parameters provide the basis for classification of TTTS, allowing severity assessment. The Quintero's staging system provides a standardized prenatal estimate on the risk of intrauterine fetal demise of one or both twins and the need for fetoscopic laser coagulation of placental vascular anastomoses or delivery depending on the gestational age. However, a proportion of TTTS cases may present without a linear progressive deterioration and no ultrasound signs of preceding staging, in rare situations, they arise even without amniotic fluid discordance. Thus, these unusual clinical presentations of TTTS have long been grouped into the category of atypical TTTS. In this review, we show the clues for diagnosis and management of different atypical cases of TTTS highlighting their underlying mechanism to improve the clinical understanding of such atypical situations, avoid misdiagnosis of TTTS, and allow a timely referral to a fetoscopic center.

Twin-to-twin transfusion syndrome: Controversies in the diagnosis and management

In twin-to-twin transfusion syndrome (TTTS) communicating placental vessels on the chorionic plate between the donor and recipient twins are responsible for the chronic imbalance of blood flow. Evidence demonstrates that fetoscopic laser ablation is superior to serial amnioreductions in terms of survival and neurological outcome for stages II-IV TTTS. However, the optimal management of stage I TTTS remains poorly understood. It is well established that all chorionic plate anastomoses should be closed by laser ablation. Compared to the selective laser method, the Solomon technique yields a significant reduction of recurrent TTTS and post-laser twin anemia polycythemia sequence (TAPS). Over the past 25 years, survival rates after fetoscopic laser surgery have significantly increased. High volume centers report up to 70% double survival and at least one survivor in >90% cases. In this review, we discuss the controversies in the diagnosis and management of TTTS, especially, the optimal management in stage I cases, very early or late diagnosis, and the optimal laser technique. Furthermore, we will discuss a stage-related outcome after laser surgery and examine whether it is necessary at all to distinguish between stages I and II. Finally, the optimal timing as well as mode of delivery after TTTS laser treatment will be discussed.

Controlled amnioreduction for twin-to-twin transfusion syndrome

Background:

Twin-to-twin transfusion syndrome (TTTS) is a severe condition causing preterm delivery, fetal death, and neurodevelopmental disorders. This study presents a data-based controlled amnioreduction (AR) protocol composed of sequential amniodrainage in treatment of TTTS.

Methods:

A total of 18 procedures were performed in 11 TTTS pregnancies at 17 to 34 weeks of gestation. The amniotic pressure was measured along with sequential removal of the amniotic fluid, 500 mL each step. The umbilical artery systolic/diastolic (S/D) ratio for each twin was measured pre- and post-AR. Long-term neurodevelopmental outcomes of all TTTS survivors were evaluated from parental answers to a phone survey.

Results:

The amniotic pressure decreased exponentially with the increased volume of removed amniotic fluid until a plateau was obtained. Changes of the S/D ratio between pre- and post-AR procedure did not reveal a clear tendency. The survival rate was 86.4% although 91% of all twins were at Quintero stage III. Long-term neurodevelopment outcomes in the 19 surviving twins were 68.4% optimal, 26.3% suboptimal, and 5.3% abnormal.

Conclusion:

The controlled AR procedure resulted in a relatively high rate of twin survival with favorable long-term neurodevelopment outcomes.

Introducing a New Predictor of Chorionicity in the Second and Third Trimesters: The “Cleft Sign”

Objective:

The aim of this study was to suggest a new sonographic sign, which could be helpful in the determination of chorionicity in twin pregnancies, during the second and third trimesters.

Materials and Methods:

This was a retrospective study evaluating the sonographic images of 50 women with twin pregnancy. Out of 50 twin pregnancy case reviewed, only 27 were included. Those patient cases that were included were scanned by a single radiologist. The presence of a hypoechoic cleft, in the thickness of placental bulk, could be detected in all of the dichorionic pregnancy cases. This sonographic appearance was referred to as the “cleft sign.”

Results:

The “cleft sign” was present in all the dichorionic diamniotic (DC-DA) twin pregnancy cases, but no similar appearance was seen in the monochorionic diamniotic (MC-DA) twins. Considering this sign, the radiologist was able to correctly diagnose the chorionicity of all 24 patients in the second and third trimester.

Conclusion:

The findings of the present study suggest a possible role for this newly identified “cleft sign.” This sonographic appearance is a hypoechoic cleft in the thickness of placenta, of dichorionic pregnancies, as an indicator of DC twin pregnancy. In this retrospective case analysis, the “cleft sign” was diagnostically significant in the second and third trimesters.

Outcomes of laser surgery for stage I twin-twin transfusion syndrome

OBJECTIVE

A recent randomized controlled trial (RCT) demonstrated no difference in 6 month survival in expectantly managed stage I twin-twin transfusion syndrome (TTTS) patients and those undergoing immediate laser surgery. We aimed to describe outcomes following immediate laser surgery at a single fetal surgery center.

METHODS

A retrospective study of monochorionic diamniotic twins diagnosed with stage I TTTS who underwent laser surgery between 16 and 26 gestational weeks from 2006 to 2019. The primary outcome was 6 month survivorship. Intact survival was also assessed. Secondarily, outcomes were compared to the RCT expectant management group.

RESULTS

Of 126 consecutive stage I TTTS patients, 114 (90.5%) met inclusion criteria. Median (range) gestational age at delivery was 34.1 (20.6-39.4) weeks. At 6 months, the proportion of patients with at-least-one survivor in the single-center-laser cohort was 97.4%, with 88.6% dual survivorship. Neurological morbidity outcomes were available in 110 pregnancies (220 fetuses). Severe neurological morbidity occurred in 2.7% (6/220), and 6 month survival without severe neurological morbidity was 90.0%. Outcomes compared favorably with the RCT expectant management group.

CONCLUSIONS

Given favorable survival and neurological outcomes, laser surgery is a reasonable treatment option for stage I TTTS at experienced fetal surgery centers. Further study is warranted to optimize treatment strategies.

Twin-to-twin transfusion syndrome and coronavirus disease 2019: Impact on diagnosis, referral, eligibility for fetoscopic laser therapy and outcomes

BACKGROUND

Because of the progressive nature of twin-to-twin transfusion syndrome, difficulties in healthcare access during the COVID-19 pandemic may lead to delayed diagnosis and referral to fetal surgery centers, which may have repercussions on outcomes.

OBJECTIVE

This study aimed to assess the clinical impact of the COVID-19 pandemic on pregnancies complicated with twin-to-twin transfusion syndrome.

STUDY DESIGN

A retrospective cohort study of consecutive monochorionic diamniotic twin pregnancies complicated with twin-to-twin transfusion syndrome evaluated in our national referral fetal surgery center at Queretaro, Mexico, for possible surgical fetoscopy was conducted. Maternal-fetal characteristics and perinatal outcomes of cases evaluated during the first year of the World Health Organization's COVID-19 pandemic declaration (March 11, 2020 to March 10, 2021) were retrospectively compared with outcomes of cases evaluated during the same period in the previous year (March 11, 2019 to March 10, 2020).

RESULTS

Overall, 109 consecutive twin-to-twin transfusion syndrome cases were evaluated during the 2-year study period, 54 during the COVID-19 pandemic and 55 in the previous year. In the former group, a higher proportion of cases with fetal surveillance interval longer than 2 weeks (70.4% vs 47.3%; P=.01); twin-to-twin transfusion syndrome complications precluding laser therapy, such as intrauterine fetal demise, preterm rupture of membranes, or cervical dilatation with prolapsed amniotic membranes (18.5% vs 1.8%; P<.01); advanced twin-to-twin transfusion syndrome (53.7% vs 36.4%; P=.07); preoperative short cervix (25.9% vs 10.9%; P<.05); and lower overall perinatal survival (56.9% vs 80.0% [P=.01; at least 1 twin] and 39.2% vs 56.4% [P=.08; both twins], respectively) were observed. A significantly lower number of cases were selected for fetoscopic laser therapy during the pandemic (75.9% vs 92.7%; P=.01), with similar postoperative outcomes seen in both study periods.

CONCLUSION

In pregnancies with twin-to-twin transfusion syndrome, the COVID-19 pandemic has shown an adverse impact involving suboptimal fetal surveillance, advanced stages at diagnosis, poorer survival rates, and higher number of complications that preclude fetoscopic laser therapy.

Neurodevelopmental Trajectories of Preterm Born Survivors of Twin-Twin Transfusion Syndrome: From Birth to 5 Years of Age

OBJECTIVE

To investigate the neurodevelopmental outcome at age 2 and 5 years in survivors of twin-twin transfusion syndrome (TTTS) treated with fetoscopic laser surgery and born premature and/or small for gestational age.

STUDY DESIGN

At 2 and 5 years of age, standardized neurologic, motor, and cognitive assessments were performed by a neonatologist, a pediatric physical therapist, and a psychologist. Behavior was assessed using a validated questionnaire completed by parents.

RESULTS

Neurodevelopmental assessment at both time points was available for 73 survivors of TTTS. Mild to moderate neurodevelopmental impairment (NDI) was detected in 34% of survivors (25 of 73) at 5 years, compared with 25% (18 of 73) at 2 years (P = .178). Severe NDI was observed in 12% (9 of 73) at 5 years and in 3% (2 of 73) at 2 years (P = .035). Mean cognitive score was lower at the 5-year follow-up (90.7 ± 12.3 vs 95.6 ± 13.1 at 2 years; P = .001), and more children were diagnosed with mild cognitive impairment at 5 years (29% vs 11% at 2 years; P = .007). When comparing individual outcomes at both time points, 35% (25 of 71) moved from a normal outcome or mild to moderate impairment at 2 years toward more severe impairment at 5 years.

CONCLUSIONS

A high rate of mild to moderate cognitive impairment and severe NDI at age 5 years was not identified at age 2 years. Our data highlight the importance of longitudinal follow-up of survivors of TTTS beyond age 2 years and emphasize the precautions that should be taken when diagnosing an absence of impairment before school age.

Intertwin differences in umbilical artery pulsatility index are associated with infant survival in twin-to-twin transfusion syndrome

OBJECTIVES

To evaluate the association of intertwin differences in umbilical artery pulsatility index (DUAPI) and infant survival in twin-to-twin transfusion syndrome (TTTS).

METHODS

Absolute DUAPI was calculated prior to laser surgery. Receiver-operating characteristics (ROC) curve analysis provided an intertwin DUAPI cutoff of 0.4 for the prediction of double twin survival to 30 days of life. Infant survival was compared between women with an intertwin DUAPI <0.4 and ≥0.4 in the whole cohort, in TTTS cases with Quintero stages I/II and in those with Quintero stages III/IV. Regression analyses were performed to evaluate the association of intertwin DUAPI <0.4 and infant survival adjusted for confounders.

RESULTS

In total, 349 TTTS cases were included. Double twin survival to 30 days was observed in 67% (234/349) of cases. Significant differences in double twin survival was seen between intertwin DUAPI groups in the whole cohort (76.8 vs. 52.2%; p<0.001), in women with TTTS Quintero stage I or II (77.8 vs. 58.5%; p=0.015) as well as in women with TTTS Quintero stage III or IV (75 vs. 49.5%; p=0.001). Intertwin DUAPI <0.4 conferred a threefold increased chance for double twin survival.

CONCLUSIONS

Small intertwin DUAPI is associated with increased double infant survival in early and advanced TTTS stages.

Early laser surgery is not associated with very preterm delivery or reduced neonatal survival in TTTS

OBJECTIVE

To evaluate the association of laser photocoagulation of placental anastomoses (LPA) prior to 18 weeks' gestation (early LPA) with very preterm delivery and neonatal survival in pregnancies with twin-twin transfusion syndrome (TTTS).

METHODS

This was a retrospective cohort study of monochorionic diamniotic twin pregnancies with TTTS undergoing LPA between 2002 and 2018 at two institutions. The rates of delivery < 28, < 30 and < 32 weeks' gestation, preterm prelabor rupture of membranes (PPROM) and 30-day survival of one or both infants were compared between pregnancies undergoing early LPA and those undergoing LPA ≥ 18 weeks' gestation. Regression analysis was performed to determine the association of early LPA with very preterm delivery and 30-day survival, adjusted for Quintero stage, study phase, selective fetal growth restriction, gestational age at delivery, maternal age ≥ 35 years, body mass index > 35 kg/m² , placental location, use of Seldinger method to place the operative trocar, size of the trocar, participating center, use of Solomon technique, cerclage and PPROM. Survival analysis using the Cox proportional hazard model was applied to examine the LPA-to-delivery interval according to the timing of surgery, adjusted for confounding variables.

RESULTS

A total of 414 TTTS pregnancies were included in the study, of which 68 (16.4%) underwent early LPA. In the total cohort, the incidence of delivery at < 28, < 30 and < 32 weeks' gestation was 22.7%, 39.6% and 53.4%, respectively. Survival of both twins and survival of at least one twin at 30 days were 67.5% and 90.8%, respectively. No significant difference was noted between pregnancies that underwent early LPA and those that had LPA ≥ 18 weeks in the rate of delivery < 28 weeks (19.1% vs 23.4%; P = 0.4), < 30 weeks (38.2% vs 39.9%; P = 0.8) and < 32 weeks (44.1% vs 55.2%; P = 0.1) and PPROM (29.0% vs 24.1%; P = 0.4), or in the incidence of double-twin survival (63.9% vs 68.1%; P = 0.5) and survival of at least one infant (91.8% vs 90.6%; P = 0.7) at 30 days. Early LPA was not associated with very preterm delivery or neonatal survival in the regression analyses. Early LPA was associated with a longer LPA-to-delivery interval compared with LPA performed ≥ 18 weeks (median, 106.9 days (range, 2-164 days) vs median, 69.3 days (range, 0-146 days); P < 0.001) when adjusted for confounding variables (hazard ratio, 2.56 (95% CI, 1.76-3.73); P < 0.001).

CONCLUSION

Laser surgery before 18 weeks is not associated with an increased rate of very preterm delivery and PPROM or with reduced neonatal survival when compared with LPA after 18 weeks. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Differentiation between TTTS Stages I vs II and III vs IV does not affect probability of double survival after laser therapy

OBJECTIVE

To compare the perinatal outcome of monochorionic twin pregnancies with twin-twin transfusion syndrome (TTTS), according to the disease severity, defined using Quintero staging, after treatment with fetoscopic laser surgery.

METHODS

This was a single-center study of 1020 consecutive cases with severe TTTS, which were treated with fetoscopic laser surgery. During the study period from January 1995 to March 2013, the participants were included at a mean ± SD gestational age of 20.8 ± 2.2 weeks. Perinatal survival analysis, including the rates of double survival and survival of at least one fetus, was undertaken according to the Quintero staging system. For blockwise comparisons of data, the whole population was divided into five chronologically consecutive study subgroups of 200 patients in each of the first four subgroups and 220 in the last one.

RESULTS

For the entire study population with known outcome (n = 1019), the rate of pregnancy with double fetal survival was 69.0% (127/184) in Stage-I, 71.4% (257/360) in Stage-II, 55.4% (236/426) in Stage-III and 51.0% (25/49) in Stage-IV TTTS cases. At least one twin survived in 91.3% (168/184) of pregnancies with Stage-I, 89.7% (323/360) of those with Stage-II, 83.1% (354/426) of those with Stage-III and 77.6% (38/49) of those with Stage-IV TTTS. The rates of double survival and survival of at least one fetus were both significantly higher in Stage-II TTTS compared with those in Stage-III TTTS cases (P < 0.001 and P = 0.011, respectively). Survival rates between pregnancies with Stage-I vs Stage-II TTTS and between those with Stage-III vs Stage-IV TTTS were not significantly different. Therefore, we combined pregnancies with Stage-I or Stage-II TTTS, and those with Stage-III or Stage-IV TTTS. The double survival rate was 70.6% (384/544) in combined Stage-I and Stage-II vs 54.9% (261/475) in combined Stage-III and Stage-IV TTTS cases (P < 0.001). At least one twin survived in 90.3% (491/544) of pregnancies with Stage-I or Stage-II TTTS vs 82.5% (392/475) in those with Stage-III or Stage-IV TTTS (P < 0.001). The double survival rate increased between the first and the last consecutive study subgroups from 59.8% (55/92) to 75.0% (96/128) (adjusted odds ratio (aOR)_{linear trend} , 1.26 (95% CI, 1.01-1.56); P = 0.037) in pregnancies with Stage-I or Stage-II TTTS and from 41.7% (45/108) to 62.0% (57/92) (aOR_{linear trend} , 1.21 (95% CI, 0.98-1.50); P = 0.082) in those with Stage-III or Stage-IV TTTS. Double survival rate was the lowest for Stage-III cases in which the donor twin was affected by severely abnormal Doppler findings (45.4% (64/141)).

CONCLUSIONS

Double survival and survival of at least one fetus in monochorionic twin pregnancies with TTTS were related significantly to Quintero stage. However, our data show that the differentiation between Stages I vs II and Stages III vs IV does not have any significant prognostic implication for perinatal survival. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Screening, Management and Delivery in Twin Pregnancy

The following AWMF guideline (DGGG/AGG & DEGUM responsible) deals with the diagnosis, screening and management of twins as well as the timing and mode of birth.Twin pregnancies can be classified as dichorionic diamniotic (DC DA), monochorionic diamniotic (MC DA) and monochorionic monoamniotic (MC MA) which are always monochorionic.Twin pregnancies can be concordant (both twins are affected) or discordant (only one twin is affected) for chromosomal defects, malformations, growth restriction and hemodynamic disorders.Chorionicity is the prognostically most significant parameter. Monochorial twins have significantly higher risks of intrauterine morbidity and mortality compared to dichorial twins.In particular, general aspects of twin pregnancies such as dating, determination of chorionicity and amnionicity, the labeling of twin fetuses and the perinatal switch phenomenon are discussed.Routine monitoring of MC and DC twin pregnancies with ultrasound at 11-13^+ 6 weeks of gestation for chromosomal defects, invasive prenatal diagnosis, first-trimester NT or CRL discrepancies, early diagnosis of fetal anatomical defects, and management of twins with abnormalities, including selective fetocide, is described.Second trimester screening and management for preterm birth, intrauterine selective growth restriction (sFGR), classification of monochorial twins with sFGR, and management of the surviving twin after the death of the co-twin are described.Complications exclusively affecting MC twins include Twin to Twin Transfusion Syndrome (TTTS) with the important topics screening, prognosis, complications of laser therapy, timing of delivery, risks for brain abnormalities and delayed neurological development, Twin Anemia-Polycythemia Sequence (TAPS) and Twin Reversed Arterial Perfusion (TRAP) Sequence. This also includes MC MA twins as well as conjoined twins.Finally, the birth mode and time for DC and MC twin pregnancies are described.The information is summarized in 62 recommendations for action, 4 tables and 8 illustrations with comprehensive background texts.The guideline is an international guideline adaptation (ISUOG, NICE) as well as a systematic literature search and is up-to-date.

Outcomes of fetoscopic laser surgery for twin-to-twin transfusion syndrome between 26 and 27 weeks of gestation in Japan

AIM

The purpose of this study was to investigate the outcomes of fetoscopic laser photocoagulation (FLP) for twin-to-twin transfusion syndrome (TTTS) in Japan.

METHODS

The retrospective cohort study (2012-2018) was conducted in monochorionic twin pregnancies that underwent FLP for TTTS between 26 and 27 weeks from 2012 to 2018. The perioperative data, maternal complications, gestational age (GA) at delivery, neonatal complications, and survival of infants at 28 days of age were analyzed. At term-equivalent age, severe neurological complications were identified by imaging study.

RESULTS

Of 644 patients, 28 (4.3%) underwent FLP between 26 and 27 weeks, and 26 were analyzed. FLP procedures were technically successful in all cases. There were no cases of major maternal complications after surgery. Preterm rupture of membranes occurred in 34.6% of cases, and the mean GA at delivery was 33.2 ± 3.1 weeks. The survival of both twins was found in 23 (88.4%) cases, and the perinatal survival rate of at least one twin at 28 days of age was 100%. Severe neurological complications were found in six (12.2%) cases out of 49.

CONCLUSIONS

FLP for TTTS between 26 and 27 weeks provided a good prognosis and caused no major maternal complications. However, severe neurological findings were found in 12% of infants.

Fetal Growth in Multiple Gestations: Evaluation and Management

Multifetal gestation pregnancies present a clinical challenge due to unique complications including growth issues, prematurity, maternal risk, and pathologic processes, such as selective intrauterine growth restriction (sIUGR), twin-to-twin transfusion syndrome (TTTS), and twin anemia-polycythemia sequence. If sIUGR is found, then management may involve some combination of increased surveillance, fetal procedures, and/or delivery. The combination of sIUGR with TTTS or other comorbidities increases the risk of pregnancy complications. Multifetal pregnancy reduction is an option when a problem is confined to a single fetus or when weighing the risks and benefits of a multifetal gestation in comparison to a singleton pregnancy.

Intrauterine fetoscopic laser surgery versus expectant management in stage 1 twin-to-twin transfusion syndrome: an international randomized trial

BACKGROUND

Selective fetoscopic laser coagulation of the intertwin anastomotic chorionic vessels is the first-line treatment for twin-twin transfusion syndrome. However, in stage 1 twin-twin transfusion syndrome, the risks of intrauterine surgery may be higher than those of the natural progression of the condition.

OBJECTIVE

This study aimed to compare immediate surgery and expectant follow-up in stage 1 twin-twin transfusion syndrome.

STUDY DESIGN

We conducted a multicentric randomized trial, which recruited from 2011 to 2018 with a 6-month postnatal follow-up. The study was conducted in 9 fetal medicine centers in Europe and the Unites States. Asymptomatic women with stage 1 twin-twin transfusion syndrome between 16 and 26 weeks' gestation, a cervix of >15 mm, and access to a surgical center within 48 hours of diagnosis were randomized between expectant management and immediate surgery. In patients allocated to immediate laser treatment, percutaneous laser coagulation of anastomotic vessels was performed within 72 hours. In patients allocated to expectant management, a weekly ultrasound follow-up was planned. Rescue fetoscopic coagulation of anastomoses was offered if the syndrome worsened as seen during a follow-up, either because of progression to a higher Quintero stage or because of the maternal complications of polyhydramnios. The primary outcome was survival at 6 months without severe neurologic morbidity. Severe complications of prematurity and maternal morbidity were secondary outcomes.

RESULTS

The trial was stopped at 117 of 200 planned inclusions for slow accrual rate over 7 years: 58 women were allocated to expectant management and 59 to immediate laser treatment. Intact survival was seen in 84 of 109 (77%) expectant cases and in 89 of 114 (78%) (P=.88) immediate surgery cases, and severe neurologic morbidity occurred in 5 of 109 (4.6%) and 3 of 114 (2.6%) (P=.49) cases in the expectant and immediate surgery groups, respectively. In patients followed expectantly, 24 of 58 (41%) cases remained stable with dual intact survival in 36 of 44 (86%) cases at 6 months. Intact survival was lower following surgery than for the nonprogressive cases, although nonsignificantly (78% and 71% following immediate and rescue surgery, respectively).

CONCLUSION

It is unlikely that early fetal surgery is of benefit for stage 1 twin-twin transfusion syndrome in asymptomatic pregnant women with a long cervix. Although expectant management is reasonable for these cases, 60% of the cases will progress and require rapid transfer to a surgical center.

Risk Profiling of the Solomon Technique versus Selective Technique of Fetoscopic Laser Surgery for Twin-Twin Transfusion Syndrome

We evaluated the outcomes and adverse events after fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) using the Solomon technique in comparison to the selective technique. A retrospective analysis of a single-center consecutive cohort of FLS-treated TTTS using the selective (January 2010 to July 2014) and Solomon (August 2014 to December 2017) techniques was performed. Among 395 cases, 227 underwent selective coagulation and 168 underwent the Solomon technique. The incidence rates of recurrent TTTS (Solomon vs. selective: 0% vs. .9%, p = .510) and twin anemia-polycythemia sequence (.6% vs. .4%, p = .670) were very low in both groups. The incidence rates of placental abruption (Solomon vs. selective: 10.7% vs. 3.5%, p = .007) and preterm premature rupture of the membranes (pPROM) with subsequent delivery before 32 weeks (20.2% vs. 7.1%, p < .001) were higher in the Solomon group. The median birth recipient weight was significantly smaller in the Solomon group (1790 g vs. 1933 g, p = .049). The rate of survival of at least one twin was significantly higher in the Solomon group (98.2% vs. 93.8%, p = .046). The Solomon technique and total laser energy were significant risk factors for pPROM (odds ratio: 2.64, 1.07, 95% CI [1.32, 5.28], [1.01, 1.13], p = .006, p = .014, respectively). These findings suggest that the Solomon technique led to superior survival outcomes but increased risks of placental abruption, pPROM and fetal growth impairment. Total laser energy was associated with the occurrence of pPROM. Close attention to adverse events is required for perinatal management after FLS to treat TTTS using the Solomon technique.

Perinatal outcomes and factors affecting the survival rate of fetuses with twin-to-twin transfusion syndrome treated with fetoscopic laser coagulation: a single-center seven-year experience

OBJECTIVES

This single-center study aimed to assess the perinatal outcomes and its associated factors in fetuses with twin-to-twin transfusion syndrome (TTTS) treated by fetoscopic laser coagulation (FLC).

METHODS

In this retrospective study, we included fetuses prenatally diagnosed with TTTS at Asan Medical Center, Seoul, Korea, between October 2011 and December 2018. All patients with TTTS stage II or higher and those with stage I TTTS coupled with symptomatic polyhydramnios or cardiac dysfunction were eligible for FLC.

RESULTS

A total of 172 cases of monochorionic diamniotic twins and one case of dichorionic triamniotic triplets were prenatally diagnosed with TTTS and treated with FLC. The median gestational ages (GAs) at diagnosis and FLC were 20.3 and 20.5 weeks, respectively. The median GA of survivors at delivery was 32.5 weeks. The overall at least one twin- and double-survival rates within 28 days after birth were 82.1% and 55.5%, respectively. The GAs at diagnosis and FLC, Quintero stage, inter-twin weight discordance, associated selective intrauterine growth restriction (sIUGR), procedure time, volume of amnioreduction, preterm prelabor rupture of membranes (PPROM) within one week after FLC, intraoperative intrauterine bleeding, and chorioamnionitis were significant predictive factors of perinatal death. Associated sIUGR, absent end-diastolic flow of umbilical artery, and abnormal cord insertion were significantly associated with donor demise in utero, whereas lower GA at diagnosis and FLC, smaller twins at FLC, pulsatile umbilical vein, and presence of mitral regurgitation were significantly associated with recipient demise in utero. Since the application of the Solomon technique, the survival rate has improved from 75.4% to 88.8%. The FLC before 17 weeks was associated with PPROM within one week after FLC and lower survival rate, whereas that after 24 weeks was associated with twin anemia-polycythemia sequence and higher survival rate. We reached a survival rate of 82% for at least one survival with only 12 procedures.

CONCLUSIONS

FLC is an effective treatment for TTTS. The learning curve reached the acceptable target faster than in previous studies. Several prenatal parameters are identified as predictive factors of fetal survival in TTTS treated with FLC.

Perinatal outcomes of twin pregnancies complicated by late twin-twin transfusion syndrome: A systematic review and meta-analysis

INTRODUCTION

Untreated twin-to-twin transfusion syndrome (TTTS) is associated with a high risk of perinatal mortality and morbidity. Laser surgery is recommended before 26 weeks of gestation. However, the optimal management in case of late TTTS (occurring after 26 weeks of gestation) is yet to be established.

MATERIAL AND METHODS

We conducted a systematic review and meta-analysis to evaluate the outcomes of monochorionic-diamniotic twin pregnancies complicated by late TTTS according to different management options (expectant, laser therapy, amnioreduction, or delivery). The primary outcome was mortality, including single and double intrauterine, neonatal, and perinatal death. Secondary outcomes were composite morbidity, neuromorbidity, respiratory distress syndrome, admission to neonatal intensive care unit, intact survival (ie, free from neurological complications), and preterm birth before <32 weeks of gestation. Outcomes were reviewed according to the management and reported for the overall population of twins and disease status (ie, donor and recipient separately). Random-effect meta-analyses of proportions were used to analyze the data.

RESULTS

Nine studies including 796 twin pregnancies affected by TTTS were included. No randomized controlled trials were available for inclusion. TTTS occurred at ≥26 weeks of gestation in 8.7% (95% CI 6.9%-10.9%; 67/769) of cases reporting TTTS at all gestations. Intrauterine death occurred in 17.7% (95% CI 4.9%-36.2%) of pregnancies managed expectantly, 5.3% (95% CI 0.9%-12.9%) of pregnancies treated with laser, and 0% (95% CI 0%-9%) after amnioreduction. Neonatal death occurred in 42.5% (95% CI 17.5%-69.7%) of pregnancies managed expectantly, in 2.8% (95% CI 0.3%-7.7%) of cases treated with laser, and in 20.2% (95% CI 6%-40%) after amnioreduction. Only one study (10 cases) reported data on immediate delivery after diagnosis with no perinatal deaths. Perinatal death incidence was 55.7% (95% CI 31.4%-78.6%) in twin pregnancies managed expectantly, 5.6% (95% CI 0.5%-15.3%) in those treated with laser, and 20.2% (95% CI 6%-40%) in those after amnioreduction. Intact survival was reported in 44.4%, 96.4%, and 78% of fetuses managed expectantly, with laser or amnioreduction, respectively.

CONCLUSIONS

Evidence regarding perinatal mortality and morbidity in twin pregnancies complicated by late TTTS according to the different managements was of very low quality. Therefore further high-quality research in this field is needed to elucidate the optimal management of these pregnancies.

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

Background

Radiofrequency ablation (RFA) is recommended to prevent potential neurological injury or intrauterine foetal death (IUFD) of the co-twin(s) in complicated monochorionic (MC) pregnancies. However, the impacts of various indications on the pregnancy outcome following RFA remain unclear. This study aimed to determine how the indications influence the perinatal outcomes in complicated MC pregnancies undergoing radiofrequency ablation.

Methods

This was a retrospective cohort study performed in a single centre. All consecutive MC pregnancies treated with RFA between July 2011 and July 2019 were included. The adverse perinatal outcomes and the survival rate were analysed based on various indications. The continuous variables with and without normal distribution were compared between the groups using Student’s t-test and Mann–Whitney U test, respectively, and for categorical variables, Chi-square and Fisher’s exact tests were used. P < 0.05 indicated a significant difference.

Results

We performed 272 RFA procedures in 268 complicated MC pregnancies, including 60 selective intrauterine growth restriction (sIUGR), 64 twin–twin transfusion syndrome (TTTS), 12 twin reversed arterial perfusion sequence (TRAPs), 66 foetal anomaly and 66 elective foetal reduction (EFR) cases. The overall survival rate of the co-twin was 201/272 (73.9%). The overall technical successful rate was determined at 201/263 (76.7%). The IUFD rate in the co-twin was 20/272 (7.4%). The TTTS group had recorded the lowest survival rate (37/64, 57. 8%), and the survival rate was significantly correlated with Quintero stages (P = 0.029). Moreover, the sIUGR III subgroup had a lower survival rate compared with sIUGR II (55.6%, versus 84.3%). The subgroup of foetal anomaly of gastroschisis or exomphalos had the highest IUFD rate (4/10, 40%), followed by sIUGR III (2/9, 22.2%) and dichorionic triamniotic (DCTA) subgroup (8/46, 17.9%). In EFR group, eight IUFD cases were all coming from the DCTA subgroup and received RFA before 17 weeks.

Conclusions

The perinatal outcome of RFA was correlated with the indications, with the lowest survival rate in TTTS IV and the highest IUFD incidence in abdominal wall defect followed by sIUGR III. Elective RFA after 17 weeks may prevent IUFD in DCTA pregnancies.

Advances and Trends in Pediatric Minimally Invasive Surgery

As many meta-analyses comparing pediatric minimally invasive to open surgery can be found in the literature, the aim of this review is to summarize the current state of minimally invasive pediatric surgery and specifically focus on the trends and developments which we expect in the upcoming years. Print and electronic databases were systematically searched for specific keywords, and cross-link searches with references found in the literature were added. Full-text articles were obtained, and eligibility criteria were applied independently. Pediatric minimally invasive surgery is a wide field, ranging from minimally invasive fetal surgery over microlaparoscopy in newborns to robotic surgery in adolescents. New techniques and devices, like natural orifice transluminal endoscopic surgery (NOTES), single-incision and endoscopic surgery, as well as the artificial uterus as a backup for surgery in preterm fetuses, all contribute to the development of less invasive procedures for children. In spite of all promising technical developments which will definitely change the way pediatric surgeons will perform minimally invasive procedures in the upcoming years, one must bear in mind that only hard data of prospective randomized controlled and double-blind trials can validate whether these techniques and devices really improve the surgical outcome of our patients.

Amniodrainage-Induced Circulatory Dysfunction in Women Treated for Twin-To-Twin Transfusion Syndrome

Twin-to-twin transfusion syndrome (TTTS) in monochorionic-diamniotic twin pregnancies usually requires fetoscopic laser ablation (FLA) followed by amniodrainage (AD). Perioperative maternal hemodynamic changes and hemodilution have been observed. Little is known about the underlying pathophysiology. We aimed to evaluate the impact of high volume amniodrainage on intrauterine pressure, placental thickness and maternal blood characteristics. A total of 18 cases of TTTS were included in this prospective pilot study. All patients were treated with FLA and subsequent AD. Intrauterine pressure and placental thickness were assessed before, during and after amniodrainage. Maternal hemoglobin, hematocrit and serum albumin were measured at admission and 24 h after the intervention. Amniodrainage led to a decrease in mean intrauterine pressure (from 30.1 ± 8.1 mmHg to 17.6 ± 3.6 mmHg (p < 0.001)) and an increase in mean placental thickness (from 16.8 ± 6.4 mm to 31.83 ± 8.64 mm (p < 0.001)). There was a positive correlation between changes in placental thickness and the amount of amniodrainage during intervention (Pearson's Rho 0.73; p = 0.001). Hematocrit decreased from 33.4 ± 3.8 (%) to 28.4 ± 3.5 (%), i.e., an increase in relative blood volume by 18 ± 10.2% (p < 0.001). Albumin decreased from 37.9 ± 0.9 g/L to 30.7 ± 2.2 g/L, i.e., an increase in relative plasma volume by 24 ± 8.1% (p < 0.001). Amniodrainage leads to uterine decompression, increased placental thickness and subsequent maternal hemodilution. We propose the term "amniodrainage-induced circulatory dysfunction" for these specific maternal hemodynamic changes in the treatment of twin-to-twin transfusion syndrome.

Neurodevelopmental impairment at 3 years of age after fetoscopic laser surgery for twin-to-twin transfusion syndrome

BACKGROUND

Data on neurodevelopmental outcomes of children surviving after fetoscopic laser surgery (FLS) for twin-to-twin transfusion syndrome (TTTS) are scarce.

METHODS

We retrospectively investigated children surviving after FLS for TTTS at 16 to 26 weeks' gestation between 2003 and 2014. Children were evaluated by standardized neurologic examinations using the Kyoto Scale 2001 at a corrected age of 3 years ± 6 months. Neurodevelopmental impairment (NDI) was defined as cerebral palsy (CP), bilateral blindness, bilateral deafness or a developmental quotient (DQ) < 70 points. Brain magnetic resonance imaging (MRI) was performed at term-equivalent age.

RESULTS

A total of 188 children from 110 twin pregnancies were evaluated. NDI was detected in 16/188 (8.5%) children, including six cases of CP (3.2%). No children had bilateral blindness or deafness. An earlier gestational age at delivery was associated with a higher incidence of NDI (P < .001). Abnormal brain MRI findings were detected in 9/16 (56%) of children with NDI, including 6/6 (100%) with CP.

CONCLUSION

The incidence of NDI in children following FLS at 3 years old was 8.5%. Prematurity is a strong risk factor for NDI. Brain MRI may predict the development of CP.

A Comparison of Spinal Anesthesia Versus Monitored Anesthesia Care With Local Anesthesia in Minimally Invasive Fetal Surgery

BACKGROUND

Minimally invasive fetal surgery is commonly performed to treat twin-to-twin transfusion syndrome with selective fetoscopic laser photocoagulation and twin-reversed arterial perfusion sequence using radiofrequency ablation. Although an increasing number of centers worldwide are performing these procedures, anesthetic management varies. Both neuraxial anesthesia and monitored anesthesia care with local anesthesia are used at different institutions. We sought to determine the efficacy and outcomes of these 2 anesthetic techniques for fetal procedures at our institution.

METHODS

All patients undergoing minimally invasive fetal surgery for twin-to-twin transfusion syndrome or twin-reversed arterial perfusion sequence over a 6-year time period (2011-2016) were reviewed. Patients receiving monitored anesthesia care with local anesthesia were compared with those receiving spinal anesthesia in both selective fetoscopic laser photocoagulation and radiofrequency ablation fetal procedures. The primary outcome examined between the monitored anesthesia care and spinal anesthesia groups was the difference in conversion to general anesthesia using a noninferiority design with a noninferiority margin of 5%. Secondary outcome measures included use of vasopressors, procedure times, intraoperative fluids administered, maternal complications, and unexpected fetal demise within 24 hours of surgery.

RESULTS

The difference in failure rate between monitored anesthesia care and spinal was -0.5% (95% CI, -4.8% to 3.7%). Patients receiving monitored anesthesia care plus local anesthesia were significantly less likely to need vasopressors, had a shorter presurgical operating room time, and received less fluid (P < .001). Operative time did not differ significantly.

CONCLUSIONS

Monitored anesthesia care plus local anesthesia is a reliable and safe anesthetic choice for minimally invasive fetal surgery. Furthermore, it decreases maternal hemodynamic instability and reduces preincision operating room time.

Perioperative fetal hemodynamic changes in twin-twin transfusion syndrome and neurodevelopmental outcome at two years of age

Objective

To investigate whether perioperative fetal hemodynamic changes in twin‐to‐twin transfusion syndrome (TTTS) are associated with neurodevelopmental impairment (NDI) at two years.

Methods

Doppler parameters of three sonograms (day before, first day after and 1 week after laser surgery for TTTS) were assessed for correlation with neurodevelopmental outcome at two years (2008‐2016). NDI was defined as: cerebral palsy, deafness, blindness, and/or a Bayley‐III cognitive/motor developmental test‐score > 2SD below the mean.

Results

Long‐term outcome was assessed in 492 TTTS survivors. NDI was present in 5% (24/492). After adjustment for severe cerebral injury (present in 4%), associated with NDI were: middle cerebral artery peak systolic velocity (MCA‐PSV) >1.5 multiples of the median (MoM) 1 day after surgery (odds ratio [OR] 4.96; 95% confidence interval [CI]: 1.17‐21.05, P = .03), a change from normal umbilical artery pulsatility index (UA‐PI) presurgery to UA‐PI >p95 postsurgery (OR 4.19; 95% CI: 1.04‐16.87, P = .04), a change from normal to MCA‐PSV >1.5MoM (OR 4.75; 95% CI: 1.43‐15.77, P = .01).

Conclusion

Perioperative fetal hemodynamic changes in TTTS pregnancies treated with laser are associated with poor neurodevelopmental outcome. Prospective research on the cerebrovascular response to altered hemodynamic conditions is necessary to further understand the cerebral autoregulatory capacity of the fetus in relation to neurodevelopmental outcome.

Perinatal outcomes of twin pregnancies affected by early twin-twin transfusion syndrome: A systematic review and meta-analysis

INTRODUCTION

Twin-to-twin transfusion syndrome (TTTS) is associated with a high risk of perinatal mortality and morbidity if not treated. However, the optimal timing and management in case of early (occurring < 18 weeks) TTTS has not been established yet.

MATERIAL AND METHODS

This is a systematic review and meta-analysis aiming at evaluating the outcomes of monochorionic diamniotic twin pregnancies complicated by early (ie before 18 weeks) TTTS according to different management options (expectant, laser therapy, amnioreduction or cord occlusion). The primary outcome was mortality, including single and double intrauterine, neonatal and perinatal death. Secondary outcomes were: composite morbidity, neuromorbidity, respiratory distress syndrome, admission to neonatal intensive care unit, intact survival (defined as survival free from neurological complications) and preterm birth < 32 weeks of gestation. All outcomes were reviewed according to the different management options (expectant, laser therapy, amnioreduction or cord occlusion) and reported FOR the overall population of twins, and for the donor and recipient separately. Subgroup analysis for TTTS occurring before 16 weeks of gestation was performed. Random-effect meta-analyses of proportions were used to analyse the data.

RESULTS

Thirteen studies were included. Early TTTS occurred in 14.3% (95% confidence interval [CI] 11.9-17.0) of cases. The incidence of intrauterine death was 19.0% (95% CI 2.6-45.5) in twins managed expectantly, 32.4% (95% CI 16.5-50.7) in those who received laser treatment and 12.5% (95% CI 4.8-23.0) in those treated with amnioreduction. The incidence of neonatal death was 22.6% (95% CI 4.2-49.8) in twins managed expectantly, 24.7% (95% CI 0.5-80.3) in those who received laser and 20.2 (95% CI 5.8-43.4) in those who had amnioreduction; it was not possible to compute the incidence of these outcomes in twins undergoing cord occlusion because of insufficient sample and lack of reporting of most of the observed outcomes. Overall, the incidence of perinatal death was 43.9% (95% CI 5.9-87.7) in twins managed expectantly, 47.3% (95% CI 21.4-70.0) in those treated with laser and 28.5% in those who had amnioreduction.

CONCLUSIONS

Twin pregnancies affected by early TTTS are at substantial risk of perinatal mortality and morbidity; however, the data come from very small studies with a high risk of selection bias.

Association between impedance to blood flow in umbilical arteries and infant survival in twin-to-twin transfusion syndrome

OBJECTIVE

To evaluate infant survival according to the Doppler pattern of impedance to blood flow in the umbilical arteries (UAs) prior to laser surgery, in pregnancies with twin-to-twin transfusion syndrome (TTTS).

METHODS

This was a retrospective study of women with a monochorionic diamniotic twin pregnancy who underwent laser surgery for TTTS between January 2012 and May 2018 at a single institution. Absolute intertwin difference in UA pulsatility index (DUAPI) was measured within 48 h prior to laser surgery. Twins with intermittent or persistent absent/reversed end-diastolic flow (EDF) in the UA (UA-EDF) were analyzed separately. Survival of both or at least one infant at birth and at 30 days postpartum was compared between pregnancies with an intertwin DUAPI of ≥ 0.4 and those with an intertwin DUAPI of < 0.4, as well as between fetuses with intermittent and those with persistent absent/reversed UA-EDF. Parametric and non-parametric tests were used for analysis. Regression analysis was performed to determine if intertwin DUAPI and intermittent or persistent absent/reversed UA-EDF were associated independently with infant survival, while controlling for gestational age at delivery, Quintero stage and other important confounding variables.

RESULTS

Of 231 TTTS pregnancies that underwent laser surgery during the study period, UA Doppler information could be retrieved for 206 and delivery information was available for 184, which comprised the study population. Rates of double-twin survival at birth were significantly higher in pregnancies with an intertwin DUAPI of < 0.4 than in those with an intertwin DUAPI of ≥ 0.4 (83.9% (78/93) vs 50.0% (12/24); P < 0.001). Double-infant survival at birth was higher in pregnancies with intermittent compared to those with persistent absent/reversed UA-EDF (73.0% (27/37) vs 36.7% (11/30); P = 0.003). Regression analysis demonstrated that an intertwin DUAPI of < 0.4 was associated with increased survival of both twins at delivery (P < 0.001) and at 30 days postpartum (P = 0.002), as well as increased survival of at least one twin at delivery (P = 0.009). Similarly, intermittent absent/reversed UA-EDF was associated with increased survival of both twins at delivery (P = 0.007) and at 30 days after birth (P = 0.015).

CONCLUSIONS

Evaluation of intertwin differences in UA impedance to blood flow as well as identification of intermittent or persistent absent or reversed UA-EDF prior to laser surgery could help in the prediction of double-infant survival at birth and to 30 days in twin pregnancies with TTTS. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Fetal therapies as standard prenatal care in Japan

With recent advances in fetal medicine, various attempts have been made to save fetuses facing perinatal death or devastating consequences despite optimal management after birth. The concept of the fetus as a patient has been established through the application of in utero treatments. This paper reviews fetal therapies in order to highlight the role of perinatal medicine as standard prenatal care. Fetal therapies consist of medical therapy, percutaneous ultrasound-guided surgery, fetoscopic surgery, and open fetal surgery. In the 1980s, with advances in ultrasound imaging, percutaneous ultrasound-guided surgeries such as vesicoamniotic shunting for lower urinary tract obstruction and thoracoamniotic shunting (TAS) for fetal hydrothorax (FHT) were started. In the 1990s, fetoscopic laser surgery (FLS) for twin-twin transfusion syndrome (TTTS) was introduced, and later, a fetoscopic approach for congenital diaphragmatic hernia was also established. The revival of open fetal surgery, introduced in the 1980s by pediatric surgeons, began in the 2010s after a successful clinical study for myelomeningocele. Although many fetal therapies are still considered experimental, some have proven effective, such as FLS for TTTS, TAS for primary FHT, and radiofrequency ablation (RFA) for twin reversed arterial perfusion (TRAP) sequence. These three fetal therapies have been approved for coverage by Japan National Health Insurance as a result of clinical studies performed in Japan. FLS for TTTS, TAS for primary FHT, and RFA for TRAP sequence have become standard prenatal care approaches in Japan. These three minimally invasive fetal therapies will help improve the perinatal outcomes of fetuses with these disorders.

Twin-twin transfusion syndrome in the era of fetoscopic laser surgery: antenatal management, neonatal outcome and beyond

Introduction: Twin-twin transfusion syndrome (TTTS) is a devastating complication of monochorionic twin pregnancy and remains a major challenge for worldwide fetal medicine specialists. In TTTS, intertwin transfusion through vascular anastomoses in the shared placenta leads to severe hemodynamic imbalance. This review summarizes the current knowledge of TTTS.Areas covered: The most recent insights concerning the management of TTTS, as well as fetal and neonatal complications are described. Relevant articles were selected based on a Pubmed search using the keywords below. Understanding of the underlying pathophysiology has improved greatly as a result of placental injection studies. Advancements in antenatal management have led to increased perinatal survival and a decreased incidence of neonatal complications, including brain injury and neurodevelopmental impairment.Expert opinion: Further opportunities for improvement comprise technological innovations in laser procedures and the prevention of preterm rupture of membranes with subsequent prematurity. A noninvasive treatment such as high-intensity focused ultrasound (HIFU) seems to hold promise for the future treatment of TTTS. Fetal MRI studies are important to improve our understanding of fetal brain injury and should relate their findings to long-term neurodevelopment. International collaboration and centralization of care are of paramount importance to ensure the best care for our patients.

A double dilemma: treatment of stage IV fetal twin-twin transfusion syndrome in the setting of maternal recurrent venous thromoembolism: a case report

Background

Fetal conditions can pose significant challenges in the management of pregnancies complicated by pre-existing maternal medical conditions.

Case presentation

We report a case of a 34-year-old woman with Stage IV Twin Twin Transfusion syndrome in the presence of maternal recurrent complex venous thromboembolic disease. Following a previous pregnancy loss, complicated by a third episode of thromboembolic disease, an inferior vena cava filter was placed. One month later, a pregnancy was confirmed and subsequently identified as a monochorionic twin pregnancy. Twin-Twin Transfusion syndrome was identified at 18 weeks’ gestation and progressed rapidly to Quintero Stage IV. In consultation with a multi-disciplinary international team, fetoscopic laser photocoagulation was performed. The pregnancy progressed to delivery of female infants at 33 weeks gestation, who have achieved all developmental milestones at 2 years of age.

Conclusions

We describe the multi-disciplinary effort to optimise the maternal condition to allow fetoscopic laser photocoagulation and continued management of the maternal and fetal conditions to a successful pregnancy outcome.

The value of echocardiography and Doppler in the prediction of fetal demise after laser coagulation for TTTS: A systematic review and meta-analysis

This study aimed to investigate the value of echocardiography and Doppler before fetoscopic laser coagulation for twin‐twin transfusion syndrome (TTTS) in the prediction of intrauterine fetal demise (IUFD). We performed a systematic review and meta‐analysis to compare preoperative parameters between fetuses with and without demise after laser surgery. Eighteen studies were included. Recipient twins have an increased risk of demise in case of preoperative absent/reversed flow (A/REDF) in the umbilical artery (odds ratio [OR] 2.76, 95% confidence interval [CI], 1.78‐4.28), absent or reversed a‐wave in the ductus venosus (OR 2.32, 95% CI, 1.70‐3.16), or a middle cerebral artery peak systolic velocity > 1.5 multiples of the median (MoM) (OR 7.59, 95% CI, 2.56‐22.46). In donors, only A/REDF in the umbilical artery (OR 3.40, 95% CI, 2.68‐4.32) and absent or reversed a‐wave in the ductus venosus (OR 1.66, 95% CI, 1.12‐2.47) were associated with IUFD. No association was found between donor‐IUFD and preoperative myocardial performance index (MPI). Two studies found an association between abnormal MPI and recipient demise. With this study, we have identified a set of preoperative Doppler parameters predictive of fetal demise after laser surgery. More research is needed to assess the utility of preoperative echocardiographic parameters such as the MPI in predicting IUFD.

What's already known about this topic?

Doppler parameters are associated with fetal demise after laser surgery.

Echocardiographic parameters are currently not used in risk stratification.

What does this study add?

A more extensive set of preoperative Doppler parameters is defined to predict post‐laser fetal demise.

The utility of preoperative echocardiographic parameters such as the MPI in predicting fetal demise remains unclear.

Maternal Complications and Hemodynamic Changes Following Intrauterine Interventions for Twin-to-Twin Transfusion Syndrome in Monochorionic Diamniotic Twin Pregnancies

Twin-to-twin transfusion syndrome (TTTS) is a challenging complication in monochorionic diamniotic (MCDA) twins. Intrauterine interventions, such as fetoscopic laser ablation and cord occlusion followed by amniodrainage, are established treatments. Little is known about maternal complications and hemodynamics following these interventions. We performed a retrospective analysis of maternal procedure-related complications and the impact of such procedures on maternal hemodynamics and blood characteristics. Within the study period, 100 women with severe TTTS treated by fetoscopic laser ablation (FLA) or cord occlusion (CO) were identified. Clinically relevant maternal complications were reported in four (4%) cases. There was a significant decrease in hemoglobin, hematocrit, and albumin between admission and postoperative measurements (all p < 0.001). Systolic and diastolic blood pressure, as well as maternal heart rate, decreased from time of skin suture to postoperative measurements (all p < 0.001). Within a 24 h interval, there was a positive correlation between hematocrit (Spearman's rho 0.325; p = 0.003), hemoglobin (Spearman's rho 0.379; p < 0.001), and albumin (Spearman's rho 0.360; p = 0.027), and the amount of amniodrainage during the intervention. Maternal procedure-related complications are relatively rare. Significant hemodynamic alterations and maternal hemodilution are common clinical findings following intrauterine interventions.

Fetal Survival Immediate after Fetoscopic Laser Ablation in Twin to Twin Transfusion Syndrome

BACKGROUND

The purpose of this study was to determine prognostic factors that can affect the fetal survival immediate after fetoscopic laser ablation.

METHODS

The study population consisted of consecutive twin pregnant women who underwent fetoscopic laser ablation with the diagnosis of twin to twin transfusion syndrome (TTTS) from 2011 to 2018 in Seoul National University Hospital. Fetal survival immediate after procedure was defined as survival to 48 hours after procedure and neonatal survival was defined as survival to 28 days of life. Clinical characteristics and ultrasound findings were compared according to the fetal survival immediate after procedure.

RESULTS

A total of 57 pregnant women with TTTS were included, and the overall fetal survival immediate after procedure was 71.1% (81/114) after fetoscopic laser ablation. Fetuses who survived immediate after procedure had higher gestational age at procedure and lower frequency of abnormal Doppler studies than those did not survive. However, the frequency of hydrops was not different between cases with fetal survival and those with fetal death. The earlier gestational age at procedure and the presence of abnormal Doppler studies were significant risk factors for fetal death even after adjustment.

CONCLUSION

Based on this data, the fetal survival immediate after procedure (fetoscopic laser treatment) in TTTS can be affected by the gestational age at procedure and the presence of abnormal Doppler studies.