Neonatal Mortality Disparities by Gestational Age in European Countries

Importance

There are wide disparities in neonatal mortality rates (NMRs, deaths <28 days of life after live birth per 1000 live births) between countries in Europe, indicating potential for improvement. Comparing country-specific patterns of births and deaths with countries with low mortality rates can facilitate the development of effective intervention strategies.

Objective

To investigate how these disparities are associated with the distribution of gestational age (GA) and GA-specific mortality rates.

Design, Setting, and Participants

This was a cross-sectional study of all live births in 14 participating European countries using routine data compiled by the Euro-Peristat Network. Live births with a GA of 22 weeks or higher from 2015 to 2020 were included. Data were analyzed from May to October 2023.

Exposures

GA at birth.

Main Outcomes and Measures

The study investigated excess neonatal mortality, defined as a rate difference relative to the pooled rate in the 3 countries with the lowest NMRs (Norway, Sweden, and Finland; hereafter termed the top 3). The Kitagawa method was used to divide this excess into the proportion explained by the GA distribution of births and by GA-specific mortality rates. A sensitivity analysis was conducted among births 24 weeks' GA or greater.

Results

There were 35 094 neonatal deaths among 15 123 428 live births for an overall NMR of 2.32 per 1000. The pooled NMR in the top 3 was 1.44 per 1000 (1937 of 1 342 528). Excess neonatal mortality compared with the top 3 ranged from 0.17 per 1000 in the Czech Republic to 1.82 per 1000 in Romania. Excess deaths were predominantly concentrated among births less than 28 weeks' GA (57.6% overall). Full-term births represented 22.7% of the excess deaths in Belgium, 17.8% in France, 40.6% in Romania and 17.3% in the United Kingdom. Heterogeneous patterns were observed when partitioning excess mortality into the proportion associated with the GA distribution vs GA-specific mortality. For example, these proportions were 9.2% and 90.8% in France, 58.4% and 41.6% in the United Kingdom, and 92.9% and 7.1% in Austria, respectively. These associations remained stable after removing births under 24 weeks' GA in most, but not all, countries.

Conclusions and Relevance

This cohort study of 14 European countries found wide NMR disparities with varying patterns by GA. This knowledge is important for developing effective strategies to reduce neonatal mortality.

Fetal and neonatal neuroimaging in twin-twin transfusion syndrome

OBJECTIVES

To describe the types of brain injury and subsequent neurodevelopmental outcome in fetuses and neonates from pregnancies with twin-twin transfusion syndrome (TTTS). Additionally, to determine risk factors for brain injury and to review the use of neuroimaging modalities in these cases.

METHODS

This was a retrospective cohort study of consecutive TTTS pregnancies treated with laser surgery in a single fetal therapy center between January 2010 and January 2020. The primary outcome was the incidence of brain injury, classified into predefined groups. Secondary outcomes included adverse outcome (perinatal mortality or neurodevelopmental impairment), risk factors for brain injury and the number of magnetic resonance imaging (MRI) scans.

RESULTS

Cranial ultrasound was performed in all 466 TTTS pregnancies and in 685/749 (91%) liveborn neonates. MRI was performed in 3% of pregnancies and 4% of neonates. Brain injury was diagnosed in 16/935 (2%) fetuses and 37/685 (5%) neonates and all predefined injury groups were represented. Four fetal and four neonatal cases of cerebellar hemorrhage were detected. Among those with brain injury, perinatal mortality occurred in 11/16 (69%) fetuses and 8/37 (22%) neonates. Follow-up was available for 29/34 (85%) long-term survivors with brain injury and the mean age at follow-up was 46 months. Neurodevelopmental impairment was present in 9/29 (31%) survivors with brain injury. Adverse outcome occurred in 28/53 (53%) TTTS individuals with brain injury. The risk of brain injury was increased after recurrent TTTS/post-laser twin anemia-polycythemia sequence (TAPS) (odds ratio (OR), 3.095 (95% CI, 1.581-6.059); P = 0.001) and lower gestational age at birth (OR per 1-week decrease in gestational age, 1.381 (95% CI, 1.238-1.541); P < 0.001).

CONCLUSIONS

Based on dedicated neurosonography and limited use of MRI, brain injury was diagnosed in 2% of fetuses and 5% of neonates with TTTS. Adverse outcome was seen in over half of cases with brain injury. Brain injury was related to recurrent TTTS/post-laser TAPS and a lower gestational age at birth. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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.

Vasoactive Management of Pulmonary Hypertension and Ventricular Dysfunction in Neonates Following Complicated Monochorionic Twin Pregnancies: A Single-Center Experience

OBJECTIVES

Twins resulting from a complicated monochorionic (MC) twin pregnancy are at risk for postnatal evolution of pulmonary hypertension (PH) and cardiac dysfunction (CD). Both pathologies are important contributors to short- and long-term morbidity in these infants. The aim of the present retrospective single-center cohort study was to evaluate the need for vasoactive treatment for PH and CD in these neonates.

METHODOLOGY

In-born neonates following a complicated MC twin pregnancy admitted to the department of neonatology of the University Children's Hospital Bonn (UKB) between October 2019 and December 2023 were screened for study inclusion. Finally, 70 neonates were included in the final analysis, with 37 neonates subclassified as recipient twins (group A) and 33 neonates as donor twins (group B).

RESULTS

The overall PH incidence at day of life (DOL) 1 was 17% and decreased to 6% at DOL 7 (p = 0.013), with no PH findings at DOL 28. The overall incidence of CD was 56% at DOL 1 and decreased strongly until DOL 7 (10%, p = 0.015), with no diagnosis of CD at DOL 28. The use of dobutamine, norepinephrine, and vasopressin at DOL 1 until DOL 7 did not differ between the subgroups, whereas the dosing of milrinone was significantly higher in Group B at DOL 1 (p = 0.043). Inhaled nitric oxide (iNO) was used in 16% of the cohort, and a levosimendan therapy was administered in 34% of the neonates. One-third of the cohort was treated with oral beta blockers, and in 10%, an intravenous beta blockade (landiolol) was administered. The maximum levosimendan vasoactive-inotropic score (LVISmax) increased from DOL 1 (12.4 [3/27]) to DOL 2 (14.6 [1/68], p = 0.777), with a significant decrease thereafter as measured at DOL 7 (9.5 [2/30], p = 0.011).

CONCLUSION

Early PH and CD are frequent diagnoses in neonates following a complicated MC twin pregnancy, and an individualized vasoactive treatment strategy is required in the management of these infants.

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.

Ultrasonographic Diagnosis of Twin-to-Twin Transfusion Syndrome

INTRODUCTION

Twin-twin transfusion syndrome (TTTS) is a typical complication of monochorionic twin pregnancies (MCTP). Placental vessels that communicate in the chorionic plate between donor and recipient, are responsible for the imbalance of blood flow. Circulatory imbalance causes hypovolemia in donor and hypervolemia in recipient fetus. In a typical case, recipient fetus develops polyhydramnios, weight gain, cardiomegaly and hydrops fetalis. In contrast, donor fetus develops oligohydramnios and fetal growth restriction.

AIM

The objective of this review is to evaluate in detail the main diagnostic aspects and add other important data for diagnosis of TTTS.

SCIENTIFIC BASES

The main diagnostic event for this condition is based on the ultrasonographic discovery of oligohydramnios-polyhydramnios sequence. Other useful elements for diagnosis, staging and prognosis are fetal urinary bladder visualization, urinary bladder volumen measurements, edema of subcutaneous and/or generalized tissue edema, Doppler flow velocity waves and cardiac evaluation.

CONCLUSION

Considerations regarding diagnosis of TTTS make it possible to emphasize that role of physicians treating patients with MCTP is to identify ultrasound sequence of oligohydramnios-polyhydramnios. Other ultrasonographic fetal data as fetal urinary bladder visualization, urinary bladder volumen measurements, edema of subcutaneous and/or generalized tissue edema, Doppler flow velocity waves and cardiac evaluation; may help diagnosis, staging and prognosis of TTTS. It is their responsibility to accurately assess severity, therapeutic possibilities and prognosis.

KEY POINTS

· The role of physicians treating patients with MCTP, regarding diagnosis of TTTS, must be to identify ultrasound sequence of oligohydramnios-polyhydramnios.. · Other ultrasonographic fetal data may help diagnosis, staging, and prognosis of TTTS as follows: fetal urinary bladder visualization, urinary bladder volume measurements, edema of subcutaneous and/or generalized tissue edema, Doppler flow velocity waves, and cardiac evaluation.. · It is physicians' responsibility to accurately assess severity, therapeutic possibilities, and prognosis of patients with MCTP and diagnosis of TTTS..

Guidelines and Recommendations for Targeted Neonatal Echocardiography and Cardiac Point-of-Care Ultrasound in the Neonatal Intensive Care Unit: An Update from the American Society of Echocardiography

Targeted neonatal echocardiography (TNE) involves the use of comprehensive echocardiography to appraise cardiovascular physiology and neonatal hemodynamics to enhance diagnostic and therapeutic precision in the neonatal intensive care unit. Since the last publication of guidelines for TNE in 2011, the field has matured through the development of formalized neonatal hemodynamics fellowships, clinical programs, and the expansion of scientific knowledge to further enhance clinical care. The most common indications for TNE include adjudication of hemodynamic significance of a patent ductus arteriosus, evaluation of acute and chronic pulmonary hypertension, evaluation of right and left ventricular systolic and/or diastolic function, and screening for pericardial effusions and/or malpositioned central catheters. Neonatal cardiac point-of-care ultrasound (cPOCUS) is a limited cardiovascular evaluation which may include line tip evaluation, identification of pericardial effusion and differentiation of hypovolemia from severe impairment in myocardial contractility in the hemodynamically unstable neonate. This document is the product of an American Society of Echocardiography task force composed of representatives from neonatology-hemodynamics, pediatric cardiology, pediatric cardiac sonography, and neonatology-cPOCUS. This document provides (1) guidance on the purpose and rationale for both TNE and cPOCUS, (2) an overview of the components of a standard TNE and cPOCUS evaluation, (3) disease and/or clinical scenario-based indications for TNE, (4) training and competency-based evaluative requirements for both TNE and cPOCUS, and (5) components of quality assurance. The writing group would like to acknowledge the contributions of Dr. Regan Giesinger who sadly passed during the final revisions phase of these guidelines. Her contributions to the field of neonatal hemodynamics were immense.

Fetal Brain Growth in the Early Second Trimester

BACKGROUND AND PURPOSE

Recent advances in fetal MR imaging technology have enabled acquisition of diagnostic images in the early second trimester. Interpretation of these examinations is limited by a lack of familiarity with the developmental changes that occur during these early stages of growth. This study aimed to characterize normal fetal brain growth between the 12th and 20th weeks of gestational age.

MATERIALS AND METHODS

This study was conducted as an observational retrospective analysis. Data were obtained from a tertiary care center's PACS database. All fetuses included had late fetal MR imaging (>20 weeks) or postnatal MR imaging, which confirmed normality. Each MR image was manually segmented, with ROIs placed to calculate the volume of the supratentorial parenchyma, brainstem, cerebellum, ventricular CSF, and extra-axial CSF. A linear regression analysis was used to evaluate gestational age as a predictor of the volume of each structure.

RESULTS

Thirty-one subjects with a mean gestational age of 17.23 weeks (range, 12-19 weeks) were studied. There was a positive, significant association between gestational age and intracranial, supratentorial parenchyma; brainstem cerebellum; intraventricular CSF; and extra-axial CSF volumes (P < .001). Growth was fastest in the supratentorial parenchyma and extra-axial CSF. Fetal sex was not associated with the volume in any of the ROIs.

CONCLUSIONS

This study demonstrates distinct trajectories for the major compartments of the fetal brain in the early second trimester. The fastest growth rates were observed in the supratentorial brain and extra-axial CSF.

Fetal growth changes and prediction of selective fetal growth restriction following fetoscopic laser coagulation in twin-to-twin transfusion syndrome

OBJECTIVE

To investigate fetal growth changes and predictive factors for selective fetal growth restriction (sFGR) in patients with twin-to-twin transfusion syndrome (TTTS) after fetoscopic laser coagulation (FLC).

METHODS

This retrospective study included twin-pregnant women with fetal TTTS who underwent FLC at our institution between 2011 and 2020. Twin pairs who survived at least 28 days after FLC and at least 28 days after birth were included. A paired t-test was used to compare the mean discordance between the estimated fetal weights at the FLC and the birth weights. The predictive factors for sFGR after FLC were evaluated using univariate and multivariate logistic regression analyses.

RESULTS

A total of 119 eligible pairs of patients who underwent FLC were analyzed. The weight percentile at birth significantly decreased after FLC in the recipients (53.7±30.4 percentile vs. 43.7±28.0 percentile; P<0.001), but increased in the donors (11.5±17.1 percentile vs. 20.7±22.8 percentile; P<0.001). Additionally, the mean weight discordance of twin pairs significantly decreased after FLC (23.9%±12.7% vs. 17.3%±15.7%; P<0.001). After FLC, Quintero stage ≥3, pre-FLC sFGR, abnormal cord insertion, and post-FLC abnormal umbilical artery Doppler (UAD) were all significantly higher in the sFGR group than the non-sFGR group. The prediction model using these variables indicated that the area under the receiver operating characteristic curve was 0.898.

CONCLUSION

The recipient weight percentile decreased, whereas donor growth increased, resulting in reduced weight discordance after FLC. The Quintero stage, pre-FLC sFGR, and post-FLC abnormal UAD were useful predictors of sFGR after FLC in TTTS.

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.

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.

A collagen plug with shape memory to seal iatrogenic fetal membrane defects after fetoscopic surgery

Iatrogenic preterm premature rupture of fetal membranes (iPPROM) after fetal surgery remains a strong trigger for premature birth. As fetal membrane defects do not heal spontaneously and amniotic fluid leakage and chorioamniotic membrane separation may occur, we developed a biocompatible, fetoscopically-applicable collagen plug with shape memory to prevent leakage. This plug expands directly upon employment and seals fetal membranes, hence preventing amniotic fluid leakage and potentially iPPROM.

Lyophilized type I collagen plugs were given shape memory and crimped to fit through a fetoscopic cannula (Ø 3 mm). Expansion of the plug was examined in phosphate buffered saline (PBS). Its sealing capacity was studied ex vivo using human fetal membranes, and in situ in a porcine bladder model.

The crimped plug with shape memory expanded and tripled in diameter within 1 min when placed into PBS, whereas a crimped plug without shape memory did not. In both human fetal membranes and porcine bladder, the plug expanded in the defect, secured itself and sealed the defect without membrane rupture.

In conclusion, collagen plugs with shape memory are promising as medical device for rapid sealing of fetoscopic defects in fetal membranes at the endoscopic entry point.

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Shape memory can be given to collagen plugs to rapidly expand in aqueous fluids.

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Within 1 min in aqueous fluid, collagen plugs with shape memory triple in diameter.

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Collagen plugs with shape memory show potency to seal fetal membrane defects.

Minimally Invasive Fetal Surgery and the Next Frontier

Most patients with congenital anomalies do not require prenatal intervention. Furthermore, many congenital anomalies requiring surgical intervention are treated adequately after birth. However, there is a subset of patients with congenital anomalies who will die before birth, shortly after birth, or experience severe postnatal complications without fetal surgery. Fetal surgery is unique in that an operation is performed on the fetus as well as the pregnant woman who does not receive any direct benefit from the surgery but rather lends herself to risks, such as hemorrhage, abruption, and preterm labor. The maternal risks involved with fetal surgery have limited the extent to which fetal interventions may be performed but have, in turn, led to technical innovations that have significantly advanced the field. This review will examine congenital abnormalities that can be treated with minimally invasive fetal surgery and introduce the next frontier of prenatal management of fetal surgical pathology.

Perinatal and neonatal outcomes for fetoscopic laser ablation for the treatment of twin twin transfusion syndrome at a single center

OBJECTIVE

To describe the perinatal and neonatal outcomes of fetal laser ablation (FLA) for the treatment of twin-twin transfusion syndrome (TTTS) in our single center institution.

STUDY DESIGN

Retrospective study of 76 treated pregnant women. Procedural complications, perinatal and neonatal outcomes analyzed. Differences in outcomes between two procedural techniques, selective and Solomon, compared.

RESULTS

FLA occurred at median gestational age (GA) of 20.8 weeks (IQR 18.1-22.9) with low incidence of procedural complications (5.3%). High survival rate with delivery of at least one neonate (96%) [95% CI: 88.9-99.2%]; 73.7% [95% CI: 62.3-83.1%] were twins. Median GA at birth was 33.1 weeks (IQR 28.0-35.0). Neonatal mortality and morbidities were 9.4% and 48.3% of cases respectively, and associated with lower GA. Solomon cases had comparatively higher median GA, and lower incidences of neonatal morbidities.

CONCLUSION

Our small single center study showed favorable outcomes for using the Solomon technique in the treatment of TTTS.

International Society for Prenatal Diagnosis 2022 DEBATE: There should be formal accreditation and ongoing quality assurance/review for units offering fetal therapy that includes public reporting of outcomes

The field of fetal therapy has so far escaped from formal accreditation and quality control. Despite that, current published evidence shows that outcomes of interventions in younger fetal therapy centers are similar to what is achieved in more experienced centers and outcomes of interventions have improved over time. The question however remains what is not being published and what should be the standard of care, given the lack of level 1 evidence from randomized controlled trials for many interventions. Formal collaborative networks such as NAFTnet and others allow for anonymized benchmarking of center outcomes, without publicly shaming (and financially punishing) underperforming centers. Large registries also allow for tracking of rare complications and may result in improved patient outcomes over time. Core outcome sets, which could serve as a basis for outcome reporting, are available for some conditions, but certainly not for all, resulting in communication difficulties between centers. Formal accreditation, quality control, and outcome reporting are hard to implement, expensive, and may result in decreasing access to care by pushing smaller centers out of the market. Despite the existing difficulties, international societies have committed to quality improvement, and fetal therapy programs are strongly recommended to participate in voluntary outcome tracking.

Different expressions of cardiac biomarkers between different types of acquired right ventricular outflow tract abnormality in monochorionic twins

OBJECTIVE

To investigate the differences in amniotic fluid cardiac biomarkers and clinical features among types of right ventricular outflow tract (RVOT) abnormality in monochorionic (MC) twins.

METHOD

This prospective study included MC twins that underwent laser surgery. Recipient or larger twins (group A) and donor or smaller twins (group B) were assessed and divided into those with a normal right ventricular outflow tract (normal RVOT), functional pulmonary atresia (fPA), or pulmonary stenosis (PS). Amniotic fluid levels of NT-proBNP (afNT-proBNP) and cardiac troponin T (afTnT) were examined during surgery.

RESULTS

Of 190 fetuses in group A, there were 14 RVOT abnormality cases (including 7 fPA and 7 PS). No group B fetuses showed RVOT abnormality findings. In group A, later and earlier gestational age at surgery were observed in fPA (25.1±2.8 weeks) and PS groups (17.8±0.9 weeks). All survived PS cases demonstrated progressive pulmonary valve obstruction, not observed in fPA groups. AfNT-proBNP were significantly higher in fPA and PS than in normal RVOT group (p<0.05). AfTnT was significantly higher in group A with PS than fPA and normal RVOT groups (p<0.05).

CONCLUSION

Among RVOT abnormality types in group A, amniotic fluid cardiac biomarkers were differently expressed, and clinical features were also differentiated. These findings provide insight into the pathophysiological influence on RVOT in MC twins. This article is protected by copyright. All rights reserved.

Perinatal and Long-Term Outcome of Endoscopic Laser Surgery for Twin-Twin Transfusion Syndrome with and without Selective Fetal Growth Restriction: A retrospective cohort study

OBJECTIVE

Report survival rates, neonatal mortality and morbidity and long-term outcomes of monochorionic(MC) twin pregnancies complicated by twin-to-twin transfusion syndrome(TTTS)or TTTS plus selective fetal growth restriction(sFGR)treated by endoscopic laser surgery.

METHODS

Retrospective cohort study including 149 MC twin pregnancies complicated by TTTS or TTTS plus sFGR.Medical records were reviewed for survival rates,neonatal mortality, neonatal morbidity and long-term outcomes at 2 and 6 years of age.

RESULTS

Survival of both babies was higher in the TTTS group than in the TTTS plus sFGR group(72.9%vs.54.8%);survival of at least one baby was similar in the two groups (90.7% and 88.1%).The incidence of severe neurological disability was not significantly different between TTTS and TTTS plus FGR group at both stages,1.9% vs 2.3% (p-value = 1) and 3.4%vs6.1%(p-value=0.31).Multivariable analysis demonstrated that intact neurological outcome at 2 years of age was related with gestational age at birth and z score birthweight, and at 6 years of age with gestational age at birth,z score birthweight and TTTS stage4.sFGR or abnormal brain findings at neonatal ultrasound were not related with impaired neurological outcome at 2 or 6 years of age.

CONCLUSIONS

In pregnancies with TTTS and TTTS plus sFGR survival of at least one baby and long-term neurological outcome are comparable between both groups. This article is protected by copyright. All rights reserved.

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.

Perinatal outcomes of fetoscopic laser surgery for twin-twin transfusion syndrome in triplet pregnancy: cohort study, systematic review and meta-analysis

OBJECTIVES

The aims of this study were to investigate the perinatal outcome of dichorionic triamniotic (DCTA) and monochorionic triamniotic (MCTA) triplet pregnancies complicated by twin-twin transfusion syndrome (TTTS) treated with fetoscopic laser photocoagulation (FLP) in two academic fetal centers, and to conduct a systematic review of previously published data to investigate perinatal survival in this targeted population.

METHODS

The first part of the study was a retrospective cohort study of prospectively collected data of consecutive triplet pregnancies with TTTS that underwent FLP at two fetal treatment centers between 2012 and 2020. Demographic, preoperative and operative variables and postoperative outcome were collected. Perinatal outcomes were investigated. The second part of the study was a systematic review and meta-analysis of studies evaluating the outcome of DCTA and/or MCTA triplet pregnancies, including our cohort study. PubMed, Web of Science and Scopus were searched from inception to September 2020. Primary outcomes were fetal survival (survival to birth), neonatal survival (survival to 28 days of age) and gestational age (GA) at birth.

RESULTS

A total of 31 sets of triplets with TTTS managed with FLP were included in the cohort study. Of these, 24 were DCTA and seven were MCTA. There were no significant differences in preoperative and operative variables between the two groups. There were also no significant differences between groups in GA at delivery or perinatal survival rate, including fetal and neonatal survival of at least one triplet, at least two triplets and all three triplets. Nine studies, including our cohort study, were included in the systematic review (156 DCTA and 37 MCTA triplet pregnancies treated with FLP). The overall fetal and neonatal survival was 79% (95% CI, 75-83%) and 75% (95% CI, 71-79%), respectively, in DCTA cases and 74% (95% CI, 52-92%) and 71% (95% CI, 49-89%), respectively, in MCTA cases. The rate of preterm birth before 28 weeks and before 32 weeks' gestation was 14% (95% CI, 4-29%) and 61% (95% CI, 50-72%), respectively, in DCTA triplets and 21% (95% CI, 3-45%) and 82% (95% CI, 62-96%), respectively, in MCTA triplets.

CONCLUSIONS

Triplet pregnancies with TTTS are at high risk of adverse perinatal outcome and preterm birth, regardless of chorionicity. The rate of survival after FLP in MCTA triplets was higher in our study than that reported in previous studies and is currently comparable with survival in DCTA triplets, which could be due to improved surgical skills. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Single fetal demise following fetoscopic ablation for twin-to-twin transfusion syndrome-cohort study, systematic review, and meta-analysis

BACKGROUND

Several studies have assessed preoperative and operative factors associated with fetal demise after laser for TTTS, yet these findings are not completely conclusive.

OBJECTIVE

This study aimed to identify risk factors for single fetal demise (recipient and donor twins) after fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome.

STUDY DESIGN

We searched PubMed, Scopus, and Web of Science systematically from the inception of the database to June 2020. We conducted a systemic review on studies investigating risk factors for fetal demise (donor and/or recipient) after fetoscopic laser photocoagulation in monochorionic pregnancies complicated with twin-to-twin transfusion syndrome. Initially, we investigated the cohort of women with twin-to-twin transfusion syndrome that underwent fetoscopic laser photocoagulation at our 2 high-volume fetal centers between 2012 and 2020 to identify risk factors for donor demise and recipient demise. Furthermore, we conducted a systematic review of the literature to better characterize these factors. Among studies that met the entry criteria, multiple preoperative and operative factors were tabulated. The random-effect model was used to pool the standardized mean differences or odds ratios and corresponding 95% confidence intervals. Heterogeneity was assessed using the I² value.

RESULTS

A total of 514 pregnancies with twin-to-twin transfusion syndrome managed with fetoscopic laser photocoagulation were included in the final analysis. Following the logistic regression, factors that remained significant for donor demise were selective fetal growth restriction (odds ratio, 1.9; 95% confidence interval, 1.3-2.8; P=.001) and umbilical artery blood flow with absent or reversed end-diastolic velocity of the donor (odds ratio, 2.06; 95% confidence interval, 1.2-3.4; P=.004). A significant factor associated with recipient demise was absent or reversed a-wave in the ductus venosus of the recipient (odds ratio, 1.74; 95% confidence interval, 1.07-3.13; P=.04). Data from 23 studies and our current cohort were included. A total of 4892 pregnancies with twin-to-twin transfusion syndrome managed with fetoscopic laser photocoagulation were analyzed for risk factors for donor demise, and 4594 pregnancies with twin-to-twin transfusion syndrome were analyzed for recipient demise. Among studies, the overall incidence rates ranged from 10.9% to 35.8% for donor demise and 7.3% to 24.5% for recipient demise. Significant risk factors for donor demise were intertwin estimated fetal weight discordance of >25% (odds ratio, 1.86; 95% confidence interval, 1.44-2.4; I², 0.0%), selective fetal growth restriction (odds ratio, 1.78; 95% confidence interval, 1.4-2.27; I², 0.0%), twin-to-twin transfusion syndrome stage III (odds ratio, 2.18; 95% confidence interval, 1.53-3.12; I², 0.0%), umbilical artery blood flow with absent or reversed end-diastolic velocity of the donor (odds ratio, 2.31; 95% confidence interval, 1.9-2.8; I², 23.7%), absent or reversed a-wave in the ductus venosus of the donor (odds ratio, 1.83; 95% confidence interval, 1.45-2.3; I², 0.0%), and presence of arterioarterial anastomoses (odds ratio, 2.81; 95% confidence interval, 1.35-5.85; I², 90.7%). Sequential selective coagulation was protective against donor demise (odds ratio, 0.31; 95% confidence interval, 0.16-0.58; I², 0.0%). Significant risk factors for recipient demise were twin-to-twin transfusion syndrome stage IV (odds ratio, 2.18; 95% confidence interval, 1.01-4.6; I², 16.5%), umbilical artery blood flow with absent or reversed end-diastolic velocity of the recipient (odds ratio, 2.68; 95% confidence interval, 1.91-3.74; I², 0.0%), absent or reversed a-wave in the ductus venosus of the recipient (odds ratio, 2.37; 95% confidence interval, 1.55-3.64; I², 60.2%), and middle cerebral artery peak systolic velocity of >1.5 multiple of the median (odds ratio, 3.06; 95% confidence interval, 1.36-6.88; I², 0.0%).

CONCLUSION

Abnormal blood flow patterns represented by abnormal Doppler studies and low fetal weight were associated with single fetal demise in women with twin-to-twin transfusion syndrome undergoing laser therapy. Although sequential selective coagulation was protective against donor demise, the presence of arterioarterial anastomoses was considerably associated with donor demise. This meta-analysis extensively investigated the association of a wide range of preoperative and operative factors with fetal demise. These findings may be important inpatient counseling, in further understanding the disease, and perhaps in improving surgical techniques.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Survival of Hydrops Fetalis with and without Fetal Intervention

Objectives: To investigate the survival rate of hydrops fetalis after fetal interventions and neonatal intensive care. Methods: We reviewed the medical records of patients diagnosed with hydrops fetalis from January 2009 to December 2019 at Changhua Christian Children’s Hospital. All cases had abnormal fluid accumulation in at least two body compartments during pre- and postnatal examination. The primary outcome measure was the mortality rate. We also collected information regarding disease etiology, duration of hospital stay, Apgar score, gestational age at birth, initial hydrops fetalis diagnosis, fetal intervention, first albumin and pH levels, and maternal history. Results: Of the 42 cases enrolled, 30 survived and 12 died; the mortality rate was 28.6%. Furthermore, 22 cases received fetal intervention, while 20 cases did not; there was no significant difference in their survival rates (75% and 68%, respectively). Survival rate was associated with gestational age at birth, initial diagnosis time, birthweight, Apgar score, initial albumin and pH levels, and gestational hypertension. Only one case was immune-mediated. Among the nonimmune-mediated cases, the three most common etiologies were lymphatic dysplasia (12/42), idiopathic disorders (10/42), and cardiovascular disorders (5/42). Conclusions: Overall, hydrops fetalis was diagnosed early, and fetal intervention was performed in a timely manner. Preterm births were more frequent, and birthweight was lower in the cases that underwent fetal intervention than in those that did not, but there was no significant between-group difference in mortality. The initial diagnosis time, gestational age at birth, birthweight, Apgar score, and first albumin and pH levels were independently associated with mortality.

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.

Fetoscopic laser ablation therapy in monochorionic diamniotic twin pregnancies with twin-to-twin transfusion syndrome treated at a single centre over 10 years: a retrospective study

OBJECTIVES

To review experience with fetoscopic laser ablation of placental anastomoses to treat monochorionic diamniotic (MCDA) twin pregnancies complicated by twin-to-twin transfusion syndrome (TTTS) in a single centre over a ten-year period.

METHODS

A retrospective study on 142 MCDA twin pregnancies complicates by TTTS treated with equatorial laser ablation of placental anastomoses (2008-2018). Solomon technique was also applied after 2013. Survival rates, neonatal outcome, intraoperative and post-laser complications were recorded, and prognostic factors analysed.

RESULTS

A total of 133 cases were included in the final analysis; 41 patients were at stage II (30.8%), 73 were at stage III (62.9%), while only 12 (9%) at stage I and two patients (1.7%) at stage IV. Solomon technique was applied in 39 cases (29.3%). Survival of both twins was 51.1% (68/133), of a single twin 20.3% (27/133), and of at least one 71.5% (95/133), with an overall survival of 61.3% (163/266). TAPS and recurrent TTTS occurred in 8 (6%) and 15 (11.3%) patients. Survival of both fetuses increased over time (44.6 vs. 57.3%). A posterior placenta (p<0.003) and the use of the Solomon technique (p<0.02) were more frequent in cases with survival of both fetuses, while TTTS recurrence was significantly associated to the loss of one or two fetuses (p<0.01). Such associations were confirmed at logistic regression analysis.

CONCLUSIONS

Survival of both twins can improve over time and seems to be favourably associated with a placenta in the posterior location and the use of the Solomon technique.

Monochorionic diamniotic twin pregnancies

About one in five twin pregnancies are monochorionic diamniotic. In these twins, transfusion imbalances may develop due to the invariably present vascular anastomoses. The most severe imbalance is twin-twin transfusion syndrome, which presents as a significant amniotic fluid difference diagnosed on ultrasound scan, usually before 26 weeks. Another transfusion imbalance is twin anemia polycythemia sequence, a severe hemoglobin difference occurring mainly after 26 weeks in previously uncomplicated pregnancies. Fetoscopic laser coagulation of the anastomoses addresses the cause of these transfusion imbalances. Besides transfusion imbalances, the monochorionic placenta may be unevenly divided, or one part may be dysfunctional, leading to an intertwin growth difference of more than 20%. Here, laser ablation of the anastomoses will usually not cure the problem but aims to protect the appropriately growing twin if the growth-restricted co-twin dies. In monochorionic twins, structural anomalies are twice as common as in singleton pregnancies, probably due to a teratogenic effect of the embryonic splitting or because of transfusion imbalances. In contrast, chromosomal anomalies appear less common, possibly because they more likely result in an early demise. Selective reduction is feasible in monochorionic pregnancies but carries increased risks of loss, miscarriage, and early birth than a selective reduction in a dichorionic setting. Finally, if one monochorionic twin dies spontaneously, its co-twin may acutely exsanguinate into the demised co-twin, which may result in the loss of both twins or brain damage in the surviving twin. This update addresses the pathophysiology, diagnosis, and management of these common complications in monochorionic diamniotic twin pregnancies.

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.

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.

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.

Twin to twin transfusion syndrome

Twin to twin transfusion syndrome (TTTS) is a common complication that typically presents in the second trimester of pregnancy in 10-15% of monochorionic twins due to net transfer of volume and hormonal substances from one twin to the other across vascular anastomoses on the placenta. Without recognition and treatment, TTTS is the greatest contributor to fetal loss prior to viability in 90-100% of advanced cases. Ultrasound diagnosis of monochorionicity is most reliable in the first trimester and sets the monitoring strategy for this type of twins. The diagnosis of TTTS is made by ultrasound with the findings of polyhydramnios due to volume overload and polyuria in one twin and oligohydramnios due to oliguria of the co-twin. Assessment of bladder filling as well as arterial and venous Doppler patterns are required for staging disease severity. Assessment of fetal cardiac function also provides additional insight into the fetal cardiovascular impacts of the disease as well as help identify fetuses that may require postnatal follow up. Fetoscopic laser ablation of the communicating vascular anastomoses between the twins is the standard treatment for TTTS. It aims to cure the condition by interrupting the link between their circulations and making them independent of one another. Contemporary outcome data after laser surgery suggests survival for both fetuses can be anticipated in up to 65% of cases and survival of a single fetus in up to 88% of cases. However, preterm birth remains a significant contributor to postnatal morbidity and mortality. Long term outcomes of TTTS survivors indicate that up to 11% of children may show signs of neurologic impairment. Strategies to minimize preterm birth after treatment and standardized reporting by laser centers are important considerations to improve overall outcomes and understand the long-term impacts of TTTS.

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.

The Detection, Outcome, and Presentation of Twin-Twin Transfusion Syndrome in Monochorionic Diamniotic Twin Pregnancies Followed with a Protocol of Fortnightly Ultrasound Examination

BACKGROUND

Evidence to support a fortnightly scan protocol for monochorionic diamniotic (MCDA) pregnancies to detect twin-twin transfusion syndrome (TTTS) is scarce. Also, TTTS-related mortality in an unselected cohort is not well documented. Finally, common knowledge suggests that a more frequent follow-up may pick up the disease at a milder stage, but little is known on the ultrasound findings before the diagnosis.

OBJECTIVES

We examine if a fortnightly ultrasound scan from 16 weeks onward detects TTTS in time. Also, we document the outcomes in a large unselected cohort of MCDA twins and examine the ultrasound findings within 14 days before diagnosis.

METHODS

Retrospective cohort of 675 MCDA twin pregnancies followed with a fortnightly scan protocol from 16 weeks onward. Timely detection of TTTS was defined as before fetal demise (stage V), ruptured membranes, or a dilated cervix. We compared the ultrasound findings before the diagnosis between stage I-II and stage III-IV.

RESULTS

A total of 82/675 (12%) pregnancies developed TTTS, of which 74/82 (90%) were detected in time. In 8/82 (10%), TTTS was diagnosed in stage V: 5 before 16 weeks and 2 after 26 weeks. Fetoscopic laser photocoagulation (FLP) of the placental anastomoses was performed in 48/82 (59%). The survival of TTTS in the entire cohort was 105/164 (64%). In contrast, survival after FLP was 77/96 (80%). In 16/19 (84%) of stage III-IV TTTS, abnormal Doppler findings preceded the diagnosis of TTTS.

CONCLUSIONS

A scheme of fortnightly ultrasound scans from 16 weeks onward detects 9 out of ten TTTS pregnancies in time. Most stage V cases presented outside the typical time window of 16 and 26 weeks. Survival rates after FLP underestimate the mortality of TTTS. Most stage III-IV cases have abnormal Doppler findings before the diagnosis of TTTS.

Neurologic Outcomes After Prenatal Treatment of Twin-Twin Transfusion Syndrome

Monochorionic twin gestations possess disproportionately higher risk for perinatal morbidity and mortality when compared with dichorionic twin pregnancies due to their potential to develop specific complications attributable to a shared placenta and intertwin placental circulation. Since the advent of fetoscopic laser surgery, outcomes of pregnancies affected by twin-twin transfusion syndrome (TTTS) have improved, with reduced rates of mortality and morbidity when compared with amnioreduction or expectant management. The focus of this article is to review the literature regarding neurologic outcomes among pediatric survivors of fetal intervention for TTTS.

Outcome of twin-twin transfusion syndrome according to Quintero stage of disease: systematic review and meta-analysis

OBJECTIVES

To report the outcome of pregnancies complicated by twin-twin transfusion syndrome (TTTS) according to Quintero stage.

METHODS

MEDLINE, EMBASE and CINAHL databases were searched for studies reporting the outcome of pregnancies complicated by TTTS stratified according to Quintero stage (I-V). The primary outcome was fetal survival rate according to Quintero stage. Secondary outcomes were gestational age at birth, preterm birth (PTB) before 34, 32 and 28 weeks' gestation and neonatal morbidity. Outcomes are reported according to the different management options (expectant management, laser therapy or amnioreduction) for pregnancies with Stage-I TTTS. Only cases treated with laser therapy were considered for those with Stages-II-IV TTTS and only cases managed expectantly were considered for those with Stage-V TTTS. Random-effects head-to-head meta-analysis was used to analyze the extracted data.

RESULTS

Twenty-six studies (2699 twin pregnancies) were included. Overall, 610 (22.6%) pregnancies were diagnosed with Quintero stage-I TTTS, 692 (25.6%) were Stage II, 1146 (42.5%) were Stage III, 247 (9.2%) were Stage IV and four (0.1%) were Stage V. Survival of at least one twin occurred in 86.9% (95% CI, 84.0-89.7%) (456/552) of pregnancies with Stage-I, in 85% (95% CI, 79.1-90.1%) (514/590) of those with Stage-II, in 81.5% (95% CI, 76.6-86.0%) (875/1040) of those with Stage-III, in 82.8% (95% CI, 73.6-90.4%) (172/205) of those with Stage-IV and in 54.6% (95% CI, 24.8-82.6%) (5/9) of those with Stage-V TTTS. The rate of a pregnancy with no survivor was 11.8% (95% CI, 8.4-15.8%) (69/564) in those with Stage-I, 15.0% (95% CI, 9.9-20.9%) (76/590) in those with Stage-II, 18.6% (95% CI, 14.2-23.4%) (165/1040) in those with Stage-III, 17.2% (95% CI, 9.6-26.4%) (33/205) in those with Stage-IV and in 45.4% (95% CI, 17.4-75.2%) (4/9) in those with Stage-V TTTS. Gestational age at birth was similar in pregnancies with Stages-I-III TTTS, and gradually decreased in those with Stages-IV and -V TTTS. Overall, the incidence of PTB and neonatal morbidity increased as the severity of TTTS increased, but data on these two outcomes were limited by the small sample size of the included studies. When stratifying the analysis of pregnancies with Stage-I TTTS according to the type of intervention, the rate of fetal survival of at least one twin was 84.9% (95% CI, 70.4-95.1%) (94/112) in cases managed expectantly, 86.7% (95% CI, 82.6-90.4%) (249/285) in those undergoing laser therapy and 92.2% (95% CI, 84.2-97.6%) (56/60) in those after amnioreduction, while the rate of double survival was 67.9% (95% CI, 57.0-77.9%) (73/108), 69.7% (95% CI, 61.6-77.1%) (203/285) and 80.8% (95% CI, 62.0-94.2%) (49/60), respectively.

CONCLUSIONS

Overall survival in monochorionic diamniotic pregnancies affected by TTTS is higher for earlier Quintero stages (I and II), but fetal survival rates are moderately high even in those with Stage-III or -IV TTTS when treated with laser therapy. Gestational age at birth was similar in pregnancies with Stages-I-III TTTS, and gradually decreased in those with Stages-IV and -V TTTS treated with laser and expectant management, respectively. In pregnancies affected by Stage-I TTTS, amnioreduction was associated with slightly higher survival compared with laser therapy and expectant management, although these findings may be confirmed only by future head-to-head randomized trials. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Prediction of Twin-to-Twin Transfusion Syndrome Using Characteristic Waveforms of Ductus Venosus in Recipient Twins

We aimed to investigate whether the alterations of time intervals and velocity-time integrals (VTIs) of ductus venosus (DV) Doppler flow could predict evolving twin-to-twin transfusion syndrome (TTTS) in monochorionic diamniotic (MD) twin pregnancies in the second trimester. DV Doppler waveforms of MD twin pregnancies were retrospectively analyzed. Time intervals and VTIs of the accelerating phase of S-wave (S1 and VTI-1), decelerating phase of S-wave (S2 and VTI-2) and phase of D-wave (D and VTI-diast) were measured in the recipient twins of TTTS and the larger twins of uncomplicated MD twins. Each parameter was normalized to total time intervals and VTIs. DV parameters of prerecipient twins in pre-TTTS conditions were analyzed. The pre-TTTS condition was defined as the condition within 2 weeks before when TTTS cases fulfilled the criteria. Both recipient twins in TTTS cases and prerecipient twins in pre-TTTS condition showed significantly shorter S1, longer S2, shorter D, smaller VTI-1, larger VTI-2 and smaller VTI-diast than did the larger twins in uncomplicated MD twins (p < .05). Receiver-operating characteristic curve analysis showed that VTI-2 had better performance, and VTI-2 >45.5% had 87.0% sensitivity, 90.9% specificity, 81.0% positive predictive value and 93.0% negative predictive value for detecting prerecipient twins. Recipient twins complicated with TTTS have characteristic alterations in time intervals and VTIs of DV Doppler flow, which is present even before fulfilling the TTTS criteria. Furthermore, VTI-2 >45.5% is a possible predictive parameter for TTTS in the second trimester.

Long-Term Outcome of Monochorionic Twins after Fetoscopic Laser Therapy Compared to Matched Dichorionic Twins

INTRODUCTION

The only causal therapy is fetoscopic laser surgery (FLS). The aims of this study were to analyze the long-term outcome of monochorionic twins treated by FLS, including their school career, need for therapy and special aid equipment, and free-time activities, and compare their outcome to matched dichorionic twins.

MATERIAL AND METHODS

Among the 57 women treated at a single fetal treatment center between 2008 and 2017 with FLS because of twin-to-twin transfusion syndrome, 25 women with 42 children were included in the FLS group. The control group consisted of 16 dichorionic twin pairs matched for birth year, gestational age (GA), birth weight, and sex. The long-term outcome was assessed by a parental questionnaire and a standardized neurodevelopmental examination for children born before 32 gestational weeks or with a birth weight lower than 1500 g. They were also registered into the Swiss Neonatal Network database. The primary outcome was event-free survival, defined as normal neurology, behavior, vision, and hearing. The secondary outcomes were school career, need for therapy and special aid equipment, and free-time activities.

RESULTS

An event-free survival was found in 32 children (76%) in the laser and in 24 children (75%) in the control group (p = 0.91). Neurological anomalies were found in 5 children (12%) in the laser group and 3 children (9%) in the control group (p = 1.00). Multiple logistic regression analysis showed that GA at delivery was the only predictive factor for event-free survival. There were no significant differences regarding school career, therapies, or special aid equipment between the 2 groups. We found that children without FLS were involved in more free-time activities and needed fewer breaks during physical activity than children with FLS during pregnancy.

CONCLUSION

The outcome of monochorionic twins treated with FLS is comparable to the outcome of dichorionic twins. Long-term neurodevelopment in the cohort was mainly dependent on GA at birth.

Monochorionic diamniotic twins: What do I tell the prospective parents?

Monochorionic diamniotic twins occur in about 1 in 300 pregnancies. Compared with dichorionic twins, they face increased risks because of the shared circulation. In about 15%, an imbalance in blood exchange occurs, such as twin-twin transfusion syndrome and twin anemia polycythemia sequence. In this review, we summarize the latest evidence on the management of monochorionic diamniotic twin pregnancies and their specific complications, with a focus on information that is relevant for prospective parents.

The impact of chorionicity on pregnancy outcome and neurodevelopment at 2 years old among twins born preterm: the EPIPAGE-2 cohort study

OBJECTIVE

To compare the short- and mid-term outcomes of preterm twins by chorionicity of pregnancy.

DESIGN

Prospective nationwide population-based EPIPAGE-2 cohort study.

SETTING

546 maternity units in France, between March and December 2011.

POPULATION

A total of 1700 twin neonates born between 24 and 34 weeks of gestation.

METHODS

The association of chorionicity with outcomes was analysed using multivariate regression models.

MAIN OUTCOME MEASURES

First, survival at 2-year corrected age with or without neurosensory impairment, and second, perinatal, short-, and mid-term outcomes (survival at discharge, survival at discharge without severe morbidity) were described and compared by chorionicity.

RESULTS

In the EPIPAGE 2 cohort, 1700 preterm births were included (850 twin pregnancies). In all, 1220 (71.8%) were from dichorionic (DC) pregnancies and 480 from monochorionic (MC) pregnancies. MC pregnancies had three times more medical terminations than DC pregnancies (1.67 versus 0.51%, P < 0.001), whereas there were three times more stillbirths in MC than in DC pregnancies (10.09 versus 3.78%, P < 0.001). Both twins were alive at birth in 86.6% of DC pregnancies compared with 80.0% among MC pregnancies (P = 0.008). No significant difference according to chorionicity was found regarding neonatal deaths and morbidities. Likewise, for children born earlier than 32 weeks, the 2-year follow-up neurodevelopmental results were not significantly different between DC and MC twins.

CONCLUSIONS

This study confirms that MC pregnancies have a higher risk of adverse outcomes. However, the outcomes among preterm twins admitted to neonatal intensive care units are similar irrespective of chorionicity.

TWEETABLE ABSTRACT

Monochorionicity is associated with adverse perinatal outcomes, but outcomes for preterm twins are comparable irrespective of their chorionicity.

Fetal cardiovascular alterations in twin-to-twin transfusion syndrome

Twin-to-twin transfusion syndrome (TTTS) is the consequence of vascular anastomoses of the shared placenta of monochorionic twin pregnancies. Both circulating inter-twin blood flow and vasoactive mediators imbalance cause hypovolemia in the donor and hypervolemia in the recipient fetus. If left untreated, TTTS has a high perinatal mortality rate and adverse long-term outcomes mainly cardiovascular and neurological. The recipient has cardiovascular changes including atrioventricular valve regurgitation, diastolic dysfunction and pulmonary stenosis/atresia. The maladaptive response to vascular changes determines a constant decreased blood flow in the donor that permanently modifies the arterial structure leading to postnatal alterations in the vascular system. Fetoscopic LASER surgery of placental vascular anastomoses may disrupt the underlying pathophysiology and improves cardiovascular function with normalization of systolic and diastolic function within weeks after treatment. The impact of cardiovascular changes is relevant for the safety of the management of a TTTS case. The improvement of the perinatal survival after intrauterine surgery leads to viable infants with the longer-term sequelae. Therefore accurate quantification of cardiovascular involvement is essential for clinicians for pregnancy management but also for patient counseling about the potential treatment options the outcome.

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.

Outcomes following selective fetoscopic laser ablation for twin-to-twin transfusion syndrome: a single-centre experience

INTRODUCTION

Fetoscopic laser photocoagulation (FLP), a treatment option for twin-to-twin transfusion syndrome (TTTS) in monochorionic twin pregnancies, is currently the treatment of choice at our centre. We previously reported on our experience of FLP from June 2011 to March 2014. This paper audits our fetal surgery performance since then.

METHODS

15 consecutive patients who underwent FLP for Stage II-III TTTS before 26 weeks of gestation from June 2011 to January 2017 were retrospectively reviewed, consisting of five cases from our initial experience and ten subsequent cases. Perioperative, perinatal and neonatal outcomes were analysed.

RESULTS

Of 15 pregnancies, 10 (66.7%) and 5 (33.3%) were for Stage II and III TTTS respectively, with FLP performed at an earlier Quintero stage in the later cohort. Overall mean gestational ages at presentation, laser and delivery were comparable between the cohorts at 19.7 (15.4-24.3) weeks, 20.3 (16.3-25.0) weeks and 31.2 (27.6-37.0) weeks, respectively. 2 (13.3%) cases had intra-amniotic bleeding and 1 (6.7%) had iatrogenic septostomy. 1 (6.7%) case had persistent TTTS requiring repeat FLP, and another (6.7%) had preterm premature rupture of membranes at seven weeks post procedure. The overall perinatal survival rate was 21 (75.0%) out of 28 infants. One mother underwent termination of pregnancy for social reasons at 1.4 weeks post procedure. Double survival occurred in 8 (57.1%) out of 14 pregnancies, while 13 (92.9%) had at least one survivor.

CONCLUSION

FLP requires a highly specialised team and tertiary neonatal facility. Continual training improves maternal and perinatal outcomes, ensuring comparable standards with international centres.

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.

Postnatal Myocardial Function in Monochorionic Diamniotic Twins with Twin-to-Twin Transfusion Syndrome following Selective Laser Photocoagulation of the Communicating Placental Vessels

BACKGROUND

Monochorionic diamniotic (MCDA) twins are at risk for developing twin-to-twin transfusion syndrome (TTTS) throughout pregnancy. This may lead to myocardial dysfunction in the recipient and/or donor twin that persists beyond delivery. Selective laser photocoagulation of the communicating placental vessels (SLPCV) attempts to mitigate the cardiovascular outcomes. The objective of this study was to characterize early postnatal myocardial performance in MCDA twins with TTTS with and without SLPCV.

METHODS

A prospective study was performed of four MCDA twin groups: (1) uncomplicated MCDA twins, (2) MCDA twins with selective fetal growth restriction, (3) MCDA twins with TTTS following SLPCV (TTTS with SLPCV), and (4) MCDA twins with TTTS who did not undergo SLPCV (TTTS without SLPCV). Fifty-four twin pairs were enrolled: 23 uncomplicated MCDA twin pairs, 15 pairs with selective fetal growth restriction, seven TTTS pairs with SLPCV, and seven TTTS pairs without SLPCV. In each group, twin pairs were divided by birth weight into donor (smaller) and recipient (larger) and compared. Echocardiography was performed on day 1, day 2, and between days 5 and 7 of age, and myocardial performance was characterized by speckle-tracking echocardiography-derived left ventricular and right ventricular longitudinal strain (LS) and systolic strain rate (LSR). Longitudinal strain and longitudinal systolic strain rate are expressed as absolute values.

RESULTS

Compared with all recipient groups, recipient TTTS without SLPCV infants had lower left ventricular LS (16 ± 3% vs 22%-24%, P < .01) and right ventricular LS (15 ± 5% vs 21%-24%, P < .01) on day 1 that persisted throughout the first week of age. Left ventricular LSR (1.7 ± 0.3 vs 2.3 ± 0.3 sec^-1, P < .05) and right ventricular LSR (1.5 ± 0.4 vs 1.7 ± 0.5 sec^-1, P < .05) were both lower in the recipient compared with the donor twin in the TTTS without SLPCV group. LS and LSR measurements were similar among all four donor twin groups.

CONCLUSIONS

Biventricular performance is diminished in recipient MCDA twins with TTTS who are not treated with SLPCV, highlighting the need for close monitoring of their hemodynamic status during the early neonatal period.

Prediction of adverse pregnancy outcome in monochorionic diamniotic twin pregnancy complicated by selective fetal growth restriction

OBJECTIVE

To identify key factors associated with adverse perinatal outcome in monochorionic diamniotic twin pregnancy complicated by selective fetal growth restriction (sFGR).

METHODS

This was a retrospective cohort study of all monochorionic diamniotic twin pregnancies diagnosed with sFGR at ≥ 16 weeks' gestation, in a single tertiary referral center between March 2000 and May 2015. The presence of coexisting twin-twin transfusion syndrome (TTTS) was noted. Fetal biometry and Doppler indices, including those of the umbilical artery (UA) and ductus venosus (DV), were recorded at the time of diagnosis. The type of sFGR was diagnosed according to the pattern of end-diastolic flow in the UA of the smaller twin. DV pulsatility indices for veins (DV-PIV) were converted to Z-scores and estimated fetal weight values to centiles, to correct for gestational age (GA). Cox proportional hazards model was used to examine for independent predictors of adverse perinatal outcome, which was defined according to survival and included both intrauterine fetal demise and neonatal death of the FGR twin.

RESULTS

We analyzed 104 pregnancies, of which 66 (63.5%) were diagnosed with Type-I and 38 (36.5%) with Type-II sFGR at initial presentation. In pregnancies complicated by Type-II sFGR, the diagnosis of sFGR was made earlier than in those complicated by Type-I sFGR (mediam GA, 19.6 vs 21.5 weeks; P = 0.012), and Type-II sFGR was associated with increased risk of adverse perinatal outcome (intrauterine demise of the smaller twin, 34.2% vs 10.6%; P = 0.004). Twin pregnancies complicated by sFGR resulting in perinatal demise had a significantly earlier diagnosis (P = 0.002) and lower birth-weight centile of the smaller twin (P < 0.01), those with Type-I sFGR had earlier GA at delivery (P = 0.007) and those with Type-II sFGR had higher DV-PIV Z-score of the smaller twin (P = 0.003), when compared with pregnancies resulting in live birth. Coexisting TTTS had no significant impact on the perinatal outcome of pregnancies diagnosed with either Type-I or Type-II sFGR (P > 0.05 for both). Earlier GA at diagnosis (hazard ratio (HR), 0.70 (95% CI, 0.56-0.88); P = 0.002), Type-II sFGR (HR, 3.53 (95% CI, 1.37-9.07); P = 0.008) and higher DV-PIV Z-score (HR, 1.36 (95% CI, 1.12-1.65); P = 0.001) were significantly associated with increased risk of adverse perinatal outcome of the smaller twin.

CONCLUSIONS

Pregnancies complicated by Type-II sFGR are diagnosed significantly earlier and are associated with increased risk of adverse perinatal outcome compared with those with Type-I sFGR. Coexisting TTTS has no significant impact on the perinatal outcome of pregnancies diagnosed with either Type-I or Type-II sFGR. Earlier GA at diagnosis, Type-II sFGR and higher DV-PIV Z-score are associated significantly with increased risk of adverse perinatal outcome of the smaller twin. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

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.

Update on twin-to-twin transfusion syndrome

Twin-to-twin transfusion syndrome (TTTS) is a serious complication that affects 10-15% of monochorionic multiple pregnancies. Communicating placental vessels on the chorionic plate between the donor and recipient twin are responsible for the imbalance of blood flow. There is evidence for the superiority of fetoscopic laser ablation over serial amnioreductions regarding survival and neurological outcome for stages II-IV TTTS. However, the optimal management of stage I is still debated. The "Solomon" technique showed a significant reduction in recurrent TTTS and post laser twin anemia-polycythemia sequence (TAPS) in comparison to the selective laser method without improvement in perinatal mortality or neonatal morbidity. Survival rates after fetoscopic laser surgery have significantly increased over the last 25 years. High volume centers report up to 70% double survival and at least one survivor in >90%. Long-term neurodevelopmental impairment occurs in about 10% of children after laser surgery. In this review we discuss the optimal management, innovations in laser technique, long-term neurodevelopmental outcome, and future aspects of TTTS treatment.

Three-dimensional power Doppler ultrasound evaluation of placental blood flow in normal monochorionic diamniotic twin pregnancies

Background

Monochorionic diamniotic (MCDA) twin pregnancies are at higher risk of adverse outcomes and complications, which are attributed to the influence of placental morphology in MCDA twins. Monitoring of placental function is an important index for clinical decisions. The aim of our study was to evaluate the placental blood flow estimated using three-dimensional power Doppler (3D-PD) ultrasound and the vascular indices distribution with gestational age (GA) in normal MCDA twin pregnancies.

Methods

One hundred four MCDA twin pregnancies and 106 singleton pregnancies (GA range, 14–32 weeks) were included in this prospective study. 3D-PD volume data of each fetus was obtained separately from the placenta at the site of umbilical cord insertion. We analyzed the volume data using sonobiopsy technique. The placental vascularization index (VI), flow index (FI) and vascularizationflow index (VFI), were auto-calculated. The means and standard deviation values of three vascular indices per fetus were calculated and regression analysis of the vascular indices as a function of GA was performed in twin pregnancies. The vascular indices of twin and singleton pregnancies were compared using independent t-test.

Results

There were no significant differences in VI, FI or VFI among the fetuses of twins (p > 0.05). These vascular indices increased over the course of pregnancy (p < 0.05). We obtained the regression equations for the indices as a function of GA in days: VI = exp. (4.369–28.533/GA) (R² = 0.699, p < 0.05), FI = exp. (3.916–13.003/GA) (R² = 0.511, p < 0.05), and VFI = exp. (3.577–37.468/GA) (R² = 0.675, p < 0.05). There were no significant differences in three vascular indices between MCDA twin and singleton groups (p > 0.05).

Conclusions

3D-PD placental data using sonobiopsy technique could reflect the placental blood flow of each twin, which could be applied to the study of placental perfusion in MCDA twin pregnancies. This study also presented the vascular indices distribution with GA in normal twin pregnancies, which might be useful for early detection of MCDA complications.

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

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