Long-term neurodevelopmental outcome in twin-to-twin transfusion syndrome

Fetal and neonatal brain injury in twins complicated by twin anemia polycythemia sequence

OBJECTIVES

To determine the rate of fetal and neonatal brain lesions and define risk factors for such lesions in pregnancies complicated by Twin Anemia Polycythemia Sequence (TAPS).

METHODS

A retrospective cohort study of monochorionic twin pregnancies which were diagnosed with TAPS in a single tertiary medical center between 2013 and 2021. Pregnancies were followed with fetal brain neurosonogram every 2 weeks and fetal brain MRI (magnetic resonance imaging) was performed when indicated at 28-32 weeks of gestation; post-natal brain imaging included neonatal brain ultrasound. Pregnancies with pre- and post-natal brain lesions were compared to those without such findings.

RESULTS

Overall, 23 monochorionic diamniotic pregnancies were diagnosed with TAPS over the study period resulting in perinatal survival of 91.3% (42/46). In 6/23 (26%) pregnancies and 7/46 (15.2%) fetuses pre- or post-natal brain lesions were detected, of whom five were the polycythemic twins and two were the anemic twins. Brain findings included intra-cerebral hemorrhage and ischemic lesions and were diagnosed prenatally in 6/7 (85.7%) cases. No risk factors for severe brain lesions were identified.

CONCLUSIONS

TAPS may place the fetuses and neonates at increased risk for cerebral injuries. Incorporation of fetal brain imaging protocols may enhance precise prenatal diagnosis and allow for accurate parental counseling and post-natal care.

Controlled amnioreduction for twin-to-twin transfusion syndrome

Background:

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

Methods:

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

Results:

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

Conclusion:

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

Perinatal risk factors of neurodevelopmental impairment after fetoscopic laser photocoagulation for twin-twin transfusion syndrome: systematic review and meta-analysis

OBJECTIVE

Monochorionic twins with twin-twin transfusion syndrome (TTTS) treated with fetoscopic laser photocoagulation (FLP) are at increased risk of neurodevelopmental impairment (NDI). This meta-analysis aimed to identify the prevalence of and perinatal risk factors for NDI in TTTS survivors treated with FLP.

METHODS

We performed a search in PubMed, EMBASE, Scopus and Web of Science, from inception to 13 February 2021, for studies evaluating perinatal risk factors for NDI in children diagnosed prenatally with TTTS managed by FLP. Data on severity of TTTS at the time of diagnosis, defined according to the Quintero staging system, FLP-related complications and perinatal outcomes were compared between children with a history of TTTS treated with FLP with and those without NDI, which was defined as performance on a cognitive or developmental assessment tool ≥ 2 SD below the mean or a defined motor or sensory disability. A random-effects model was used to pool the mean differences or odds ratios (OR) with the corresponding 95% CIs. Heterogeneity was assessed using the I² statistic.

RESULTS

Nine studies with a total of 1499 TTTS survivors were included. The overall incidence of NDI was 14.0% (95% CI, 9.0-18.0%). The occurrence of NDI in TTTS survivors was associated with later gestational age (GA) at FLP (mean difference, 0.94 weeks (95% CI, 0.50-1.38 weeks); P < 0.0001, I²  = 0%), earlier GA at delivery (mean difference, -1.44 weeks (95% CI, -2.28 to -0.61 weeks); P = 0.0007, I²  = 49%) and lower birth weight (mean difference, -343.26 g (95% CI, -470.59 to -215.92 g); P < 0.00001, I²  = 27%). Evaluation of different GA cut-offs showed that preterm birth before 32 weeks was associated with higher risk for NDI later in childhood (OR, 2.25 (95% CI, 1.02-4.94); P = 0.04, I²  = 35%). No statistically significant difference was found between cases with and those without NDI with respect to Quintero stage of TTTS, recipient or donor status, development of postlaser twin anemia-polycythemia sequence, recurrence of TTTS and incidence of small- for-gestational age or cotwin fetal demise.

CONCLUSIONS

TTTS survivors with later GA at the time of FLP, earlier GA at delivery and lower birth weight are at higher risk of developing NDI. No significant association was found between Quintero stage of TTTS and risk of NDI. Our findings may be helpful for parental counseling and highlight the need for future studies to understand better the risk factors for NDI in TTTS survivors. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Perinatal outcomes of intrauterine transfusion for the surviving twin in monochorionic twin gestation involving a single fetal demise

AIM

This study aimed to evaluate the feasibility and outcome of intrauterine transfusion (IUT) for the surviving co-twin in monochorionic diamniotic (MCDA) twin gestations involving single intrauterine fetal death (sIUFD).

METHODS

Cases of MCDA twin gestations involving emergent IUT for co-twins experiencing acute feto-fetal hemorrhage (AFFH) subsequent to sIUFD during the second trimester were reviewed. Fetal anemia was confirmed via fetal blood sampling, and perinatal data were retrieved from medical charts to determine the outcomes of surviving co-twins. A poor outcome at 28 days of age was defined as fetal death, neonatal death or neurological impairment such as severe intraventricular hemorrhage or cystic periventricular leukomalacia (PVL).

RESULTS

This study included 16 cases of sIUFD diagnosed at a median of 22.5 weeks of gestation (range: 18-25 weeks). The median interval in hours between diagnosis of fetal demise and IUT was approximately 4.2 (0-22) hours. All cases achieved IUT without significant intraoperative complications. Four cases experienced a fetal loss of the co-twin, whereas 12 co-twins were born alive (including 9 preterm births), with only 1 poor outcome in a preterm infant with PVL.

CONCLUSION

IUT may be a feasible prenatal intervention for surviving co-twins with AFFH. However, more extensive or pooled studies are needed to determine the efficacy of this intervention.

The incidence of unexpected critical complications in monochorionic diamniotic twin pregnancies according to the interval period between ultrasonographic evaluations

AIM

This study aimed to evaluate the incidence of unexpected critical complications (UCC) in monochorionic diamniotic (MCDA) twin pregnancies according to ultrasonographic scan interval.

METHODS

This retrospective single-center cohort study, conducted between January 2005 and April 2015, investigated the incidence of UCC in patients with MCDA twin pregnancies undergoing weekly ultrasound (Group A) and those undergoing biweekly ultrasound (Group B). We also examined the incidence of predictable critical complications according to ultrasound interval.

RESULTS

Of all 385 cases, the total incidence of UCC was 20 (5.2%), including 14 cases of twin-twin transfusion syndrome and 6 cases of intrauterine fetal death. The incidence of UCC was 3.9% in Group A and 9.0% in Group B (P = 0.046). In contrast, the incidence of predictable critical complications was 6.7% in Group A and 9.0% in Group B (P = 0.440).

CONCLUSION

The incidence of UCC in patients with MCDA twin pregnancies was significantly lower in patients undergoing weekly ultrasound. Our results suggest that weekly ultrasound evaluation for patients with MCDA pregnancy is more effective for early detection of UCC such as intrauterine fetal death and twin-twin transfusion syndrome ; however, further investigations are needed to determine whether weekly ultrasound evaluation can improve clinical outcomes.

Severe gyration and migration disorder in fetofetal transfusion syndrome: two case reports and a review of the literature on the neurological outcome of children with lesions on neuroimaging

INTRODUCTION

Fetofetal transfusion syndrome is a dreaded cause of morbidity and mortality in monochorionic pregnancies.

CASE REPORTS

We present two pairs of twins one of which we have followed for more than 6 years. The donors suffer from cerebral palsy, orofacial, and motor problems, and both are significantly smaller than their recipient twins. Interestingly, cranial MRI revealed medial frontal lobe polymicrogyria, ventriculomegaly, and decreased thickness in both parietal lobes in both donors. We suggest this as a possible feature of fetofetal transfusion syndrome.

REVIEW

A minireview of the literature on neuroimaging and neurodevelopmental outcome in fetofetal transfusion syndrome is presented.

CONCLUSION

While the close resemblance of the imaging features of both cases is likely incidental further study of a connection between migration and gyration disorders and fetofetal transfusion syndrome is warranted.

Renal function in neonates with twin-twin transfusion syndrome treated with or without fetoscopic laser surgery

The aim of this study is to investigate the short-term renal function in neonates with twin-twin transfusion syndrome (TTTS), treated with fetoscopic laser surgery (laser group) or conservatively (non-laser group). Creatinine and urea levels and urine output were recorded in the first week after birth. Primary outcome was short-term renal dysfunction, defined as a creatinine level of >100 μmol/L during the first week postpartum. We evaluated 312 twins (laser group, n = 274; non-laser group, n = 38). Median creatinine and urea levels were lower in the laser group than in the non-laser group (71 versus 82 μmol/L, p = 0.002). Short-term renal dysfunction was lower in the laser group compared to the non-laser group (7.2 versus 34.4%, p < 0.001). Within the laser group, creatinine levels were significantly higher in the subgroup with incomplete laser surgery compared to twins with successful laser surgery (76 versus 69 μmol/L, p = 0.018). No differences were found between donors and recipients except for a higher incidence of oliguria in donors in the non-laser group on day 1.

CONCLUSION

Short-term renal dysfunction occurs less frequently in TTTS twins treated with fetoscopic laser coagulation, particularly after complete surgery, suggesting that laser surgery may have a protective effect on renal function. What is Known: • Antenatally, donor twins in TTTS have severe oliguria due to chronic hypovolemia and impaired renal perfusion • Postnatally, donor twins may suffer from severe renal complications, particularly in TTTS twins treated conservatively. What is New: • The incidence of short-term renal failure in TTTS twins treated with complete laser surgery is low. • After incomplete laser surgery, the incidence of short-term renal dysfunction is increased.

Lower perinatal mortality in preterm born twins than in singletons: a nationwide study from The Netherlands

BACKGROUND

Twin pregnancies are at increased risk for perinatal morbidity and death because of many factors that include a high incidence of preterm delivery. Compared with singleton pregnancies, overall perinatal risk of death is higher in twin pregnancies; however, for the preterm period, the perinatal mortality rate has been reported to be lower in twins.

OBJECTIVE

The purpose of this study was to compare perinatal mortality rates in relation to gestational age at birth between singleton and twin pregnancies, taking into account socioeconomic status, fetal sex, and parity.

STUDY DESIGN

We studied perinatal mortality rates according to gestational age at birth in 1,502,120 singletons pregnancies and 51,658 twin pregnancies without congenital malformations who were delivered between 2002 and 2010 after 28 weeks of gestation. Data were collected from the nationwide Netherlands Perinatal Registry.

RESULTS

Overall the perinatal mortality rate in twin pregnancies (6.6/1000 infants) was higher than in singleton pregnancies (4.1/1000 infants). However, in the preterm period, the perinatal mortality rate in twin pregnancies was substantially lower than in singleton pregnancies (10.4 per 1000 infants as compared with 34.5 per 1000 infants, respectively) for infants who were born at <37 weeks of gestation; this held especially for antepartum deaths. After 39 weeks of gestation, the perinatal mortality rate was higher in twin pregnancies. Differences in parity, fetal sex, and socioeconomic status did not explain the observed differences in outcome.

CONCLUSION

Overall the perinatal mortality rate was higher in twin pregnancies than in singleton pregnancies, which is most likely caused by the high preterm birth rate in twins and not by a higher mortality rate for gestation, apart from term pregnancies. During the preterm period, the antepartum mortality rate was much lower in twin pregnancies than in singleton pregnancies. We suggest that this might be partially due to a closer monitoring of twin pregnancies, which indirectly suggests a need for closer surveillance of singleton pregnancies.

Long-Term Neurodevelopmental Outcome in Survivors of Twin-to-Twin Transfusion Syndrome

Twin-twin transfusion syndrome (TTTS) is a severe complication of monochorionic (MC) twin pregnancies associated with high perinatal mortality and morbidity rates. Management in TTTS is a major challenge for obstetricians and neonatologists. Twins with TTTS are often born prematurely after an extremely distressing and highly hazardous fetal period. Follow-up studies report varying rates of cerebral palsy (CP) and long-term neurodevelopmental impairment (NDI). This review discusses the latest findings on the long-term outcome of TTTS survivors, possible risk factors for long-term impairment, and provides recommendations for future research.

DNA Methylation Changes in the IGF1R Gene in Birth Weight Discordant Adult Monozygotic Twins

Low birth weight (LBW) can have an impact on health outcomes in later life, especially in relation to pre-disposition to metabolic disease. Several studies suggest that LBW resulting from restricted intrauterine growth leaves a footprint on DNA methylation in utero, and this influence likely persists into adulthood. To investigate this further, we performed epigenome-wide association analyses of blood DNA methylation using Infinium HumanMethylation450 BeadChip profiles in 71 adult monozygotic (MZ) twin pairs who were extremely discordant for birth weight. A signal mapping to the IGF1R gene (cg12562232, p = 2.62 × 10−8), was significantly associated with birth weight discordance at a genome-wide false-discovery rate (FDR) of 0.05. We pursued replication in three additional independent datasets of birth weight discordant MZ pairs and observed the same direction of association, but the results were not significant. However, a meta-analysis across the four independent samples, in total 216 birth-weight discordant MZ twin pairs, showed a significant positive association between birth weight and DNA methylation differences at IGF1R (random-effects meta-analysis p = .04), and the effect was particularly pronounced in older twins (random-effects meta-analysis p = .008, 98 older birth-weight discordant MZ twin pairs). The results suggest that severe intra-uterine growth differences (birth weight discordance >20%) are associated with methylation changes in the IGF1R gene in adulthood, independent of genetic effects.

Short-Term Postnatal Renal Function in Twin Anemia-Polycythemia Sequence

OBJECTIVE

To evaluate the short-term renal function in neonates with twin anemia-polycythemia sequence (TAPS).

METHODS

All consecutive monochorionic twins with TAPS with double survivors admitted to three European centers were included in this retrospective study. Each twin pair was matched for gestational age at birth with a control twin pair unaffected by TAPS or twin-twin transfusion syndrome. Creatinine and urea levels in the first week after birth were recorded. Short-term postnatal renal dysfunction was defined as creatinine >100 μmol/l during the first week after birth.

RESULTS

A total of 52 TAPS twin pairs and 52 control twin pairs with a median gestational age of 31 weeks at birth were included in the study. In the TAPS group, donors had higher mean creatinine levels compared to recipients, 85 versus 71 μmol/l, respectively (p = 0.001). Short-term renal dysfunction was detected in 26.0% (13/50) of the donors versus 6.3% (3/48) of the recipients (p = 0.022). In the control group, no inter-twin differences in creatinine levels were found.

CONCLUSIONS

Donor twins with TAPS have higher creatinine levels than recipient twins, suggesting that chronic inter-twin transfusion in TAPS may also cause short-term renal dysfunction. Long-term renal consequences in TAPS donors require further investigation.

Twin-twin transfusion syndrome: neurodevelopmental screening test

OBJECTIVE

To assess the neurodevelopmental functions (cognition, language and motor function) of survivors of twin-twin transfusion syndrome (TTTS).

METHOD

Observational cross-sectional study of a total of 67 monochorionic diamniotic twins who underwent fetoscopic laser coagulation (FLC) for treatment of TTTS. The study was conducted at the Center for Investigation in Pediatrics (CIPED), Universidade Estadual de Campinas. Ages ranged from one month and four days to two years four months. Bayley Scales of Infant and Toddler Development Screening Test-III, were used for evaluation.

RESULTS

Most children reached the competent category and were classified as having appropriate performance. The preterm children scored worse than term infants for gross motor subtest (p = 0.036).

CONCLUSION

The majority of children reached the expected development according to their age. Despite the good neurodevelopment, children classified at risk should be monitored for development throughout childhood.

Long-term neurologic outcomes after common fetal interventions

OBJECTIVE

Fetal interventions have clearly decreased mortality, but the neurological outcomes of survivors are of critical concern. Here we consolidated available data on long-term neurological outcomes after common fetal interventions to guide counseling, management, and future research.

STUDY DESIGN

Published studies assessing long-term neurological outcomes after common fetal interventions from 1990 through 2014 were collected. We included all studies with a cohort of more than 5 patients and with follow-up of 1 year or longer. We divided procedures into those performed for singletons and for multiples. Singleton procedures included amnioinfusion for preterm premature rupture of membranes, intrauterine transfusion for red cell alloimmunization-associated anemia, intrauterine transfusion for parvovirus-associated anemia, vesicoamniotic shunts, thoracoamniotic shunts, ventriculoamniotic shunts, fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia, and open fetal cases by myelomeningocele and others. Multiple procedures included those done for monochorionic twins including serial amnioreduction, selective fetoscopic laser photocoagulation, and selective termination.

RESULTS

Of 1341 studies identified, 28 met the inclusion criteria. We combined available literature for all procedures. Studies varied in their length of follow-up and method of assessing neurological status. Neurological outcome after intervention varied by procedure but was normal in 40-93%, mildly impaired in 3-33%, and severely impaired in 1-40%. Follow-up to school age was rare with the exception of procedures for monochorionic twins.

CONCLUSION

Fetal treatments have been successful in achieving survival in previously hopeless cases, but success should also be determined by the outcomes of survivors. Except for monochorionic twins, there is a dearth of reported long-term outcomes. Standardized reporting of long-term neurological sequelae is imperative so that meaningful analysis and study comparisons can be made.

Neurodevelopmental outcome of twins at two years of age according to the planned mode of delivery

OBJECTIVES

To determine neurodevelopment at two years in twins.

METHODS

At two years of age, all twins ≥32 weeks, delivered in our center and not randomized in the Twin Birth Study, underwent a neurodevelopment screen using the Ages and Stages Questionnaire (ASQ). Children with ≥1 abnormal ASQ domain score were evaluated by a pediatrician. Results were documented according to a planned cesarean section (PCS) or a planned vaginal delivery (PVD).

RESULTS

An ASQ was obtained from 185 children (67%). No significant differences in percentages of abnormal scores were found between the PCS group and the PVD group or between twins A and B. Pediatric assessment revealed three children with a neurodevelopmental delay. Five other children were already under pediatric or general practitioner care for other reasons. One child with a congenital anomaly was born by a PCS, two twins A and five twins B were born in the PVD group.

CONCLUSION

ASQ screening revealed no significant differences in abnormal neurodevelopment in twins at two years of age according to the mode of delivery. Pediatric assessment suggested an increased incidence for abnormal neurodevelopment in twins B born by PVD.

What-and why-the pathologist should know about twin-to-twin transfusion syndrome

Approximately 20% of all twin pregnancies are monochorionic. Between 9% and 15% of all monochorionic twin gestations are complicated by severe chronic twin-to-twin transfusion syndrome (TTTS), characterized by a gradual shift of blood volume from the donor twin to the recipient twin through placental vascular connections [1 - 3] . The prognosis of severe, untreated chronic TTTS diagnosed in midtrimester fetuses is extremely poor, with mortality rates exceeding 70% [4] . Since publication of the results of the Eurofoetus trial in 2004, laser photocoagulation of the intertwin anastomoses has become accepted as the optimal first-line therapy for severe TTTS diagnosed before 26 weeks of gestation. While laser treatment of vascular communications was initially limited to selected fetal treatment centers, its increasingly widespread use has resulted in the exposure of more pathologists, even in less specialized institutions, to laser-treated placentas. Furthermore, the surge in laser coagulation has revived the general medical, scientific, and public interest in the placental and choriovascular findings in monochorionic twin placentas. The pathologist's understanding of the pathophysiology of TTTS and of TTTS-associated placental pathology, including the findings related to laser ablation of the anastomoses, can be of great benefit to the involved obstetric/neonatal/surgical team and, ultimately, to the patients. In this review, we summarize the current knowledge of the placental contributions to TTTS and other complications of monochorionic twinning and describe the strengths and limitations of placental examination in these settings. It is our expectation that overviews such as this may serve as a template to generate consensus guidelines for standardized and evidence-based pathologic evaluation of monochorionic twin placentas.

Preterm twin and triplet pregnancies are at increased risk for the development of cystic periventricular leukomalacia

BACKGROUND

An increased risk of cerebral palsy in multiples has been reported.

AIMS

To determine the risk for the development of periventricular leukomalacia (PVL) of twin and triplet pregnancy.

STUDY DESIGN

Retrospective single-centre study at a tertiary care university hospital.

SUBJECTS

Infants ≤ 35 weeks gestational age born between 1988 and 2008.

OUTCOME MEASURES

Risk of twin and triplet compared to singleton pregnancy regarding development of PVL in one offspring.

RESULTS

Of 6195 infants 117 singletons and 39 multiples were diagnosed as having cystic PVL. Perinatal data did not differ as did not ultrasonographic findings and neurologic outcome. The relative risk (RR) of a twin pregnancy resulting in at least one infant with PVL when born prior to 36 weeks was 2.181 (CI 95% 1.474-3.228, p < .0001), and 6.793 (CI 95% 2.470-13.108, p < .0001) of a triplet pregnancy. In-vitro fertilisation was present in 3% of affected twins compared to 100% in triplets (p < .001).

CONCLUSION

We found an increased risk for PVL in preterm twin and triplet pregnancies.

The vascular anastomoses in monochorionic twin pregnancies and their clinical consequences

Monochorionic twin pregnancies are at increased risk of adverse outcome because of the vascular anastomoses that connect the 2 fetal circulation systems. The shared circulation is responsible for some unique complications in monochorionic twins, such as the twin-to-twin transfusion syndrome, the twin anemia polycythemia sequence, the twin reversed arterial perfusion sequence, and monoamniotic twinning. Another consequence of the shared circulation is that the well-being of one twin critically depends on that of the other. In this review, we will describe the technique of placental injection. Further, we will discuss the role of the vascular anastomoses in each of the complications described above and provide an update on their management.

Neurodevelopmental outcomes of twins

In population-based studies, the prevalence of neurodevelopmental disability is consistently higher in twins than singletons. This is largely because birth weight and gestational age (GA) distributions of twin births are shifted to the left when compared with singleton births, and lower birth weight and lower GA are associated with increased risk of neurodevelopmental disability. From a pathophysiologic perspective, a question of interest is whether neurodevelopmental outcomes of twins differ from singletons after controlling for covariates. If significant differences in outcomes persist, this would suggest that the twining process itself or something intrinsic to shared life in the womb may be responsible for observed differences. From a clinical perspective, when counseling parents at risk for preterm delivery of twins, it is useful to understand how twin outcomes compare relative to singleton outcomes at the same birth weight or GA. The purpose of this review is to examine the long-term neurodevelopmental outcomes of twins compared with singletons with control for important covariates.

Fetal and maternal complications after selective fetoscopic laser surgery for twin-to-twin transfusion syndrome: a single-center experience

OBJECTIVE

To report the incidence of fetal and maternal complications after selective fetoscopic laser surgery for twin-to-twin transfusion syndrome (TTTS).

METHODS

A total of 150 cases of TTTS were treated from January 2004 to June 2009 (period 1, 2004-2006, 62 cases; period 2, 2007 to June 2009, 88 cases). Fetal complications (double and single intrauterine fetal death, recurrence of TTTS, twin anemia-polycythemia sequence (TAPS), reversal of TTTS, cerebral lesions in one twin) and maternal complications were recorded, and retrospectively analyzed.

RESULTS

Nineteen (12.6%), 58 (38.7%), 61 (40.7%) and 12 cases (8.0%) were classified preoperatively as Quintero stage I, II, III and IV, respectively. The anterior placenta was described in 73 cases (48.6%). Double and single fetal death occurred overall in 7.3 and 36.0% of cases, respectively. The rate of recurrence was 11.3%, of TAPS 3.3%, and of reversal of TTTS 1.3%. Cerebral lesions were diagnosed in 3 donors (2.0%). Eighteen cases (12.0%) of fetal complications had a second procedure (6 repeat laser, 4 serial amnioreduction, 8 bipolar cord coagulation). Pregnancies undergoing a second procedure delivered at a median gestational age of 30.2 weeks compared to 32.1 weeks for those not repeating (p = 0.04). Perinatal survival of at least one twin improved from 66.1 to 79.5% (p = 0.06) in the two consecutive periods. For every 10 laser surgeries performed, there was an average improvement of 1.5% in the predicted percentage of survival of at least one twin (OR 1.09, 95% CI 1.00-1.19). Major maternal complications occurred in 9 cases (6.0%), 3 of which required admission to intensive care unit.

CONCLUSIONS

Fetal complications are common after fetoscopic laser surgery. In this experience, an increasing number of procedures improved the performance of a new fetoscopic laser center.

Parenting Stress and Psychosocial Health in Mothers with Twin–Twin Transfusion Syndrome Managed with Laser Surgery: A Preliminary Study

Twin–twin transfusion syndrome (TTTS) is a severe complication of twin pregnancies with high risk for perinatal mortality and long-term morbidity. This cross-sectional cohort study aimed to determine parenting stress and psychosocial health in mothers with a pregnancy complicated by TTTS that had been managed with laser ablation of communicating placental vessels. Questionnaires were sent to the mothers for completion: Parenting Stress Index (PSI), Edinburgh Postnatal Depression Scale (EPDS) and a semi-structured questionnaire related to mental health problems and support received from health professionals. Thirty-seven mothers were sent questionnaires with 32 being returned. The results showed that 47% of women had total scores equal to or greater than the 85th percentile on the PSI, which is considered abnormally high. Twenty-six per cent of mothers had evidence of depression on the EPDS. Mothers of children with prolonged medical conditions or neurological problems had significantly higher scores (p =.011). Parenting stress was not associated with high scores on the EPDS. Medical and midwifery staff were considered to provide high levels of support, with social work providing none or low levels of support. In conclusion, women whose TTTS pregnancy was managed by laser surgery have high levels of parenting stress. As the results showed that parenting stress cannot be predicted at the time of hospitalization, it is suggested that more support should be provided in hospital with further follow-up after discharge.

Perinatal Outcomes With Laser Surgery for Twin–Twin Transfusion Syndrome

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

Intrauterine Growth and Cerebral Palsy in Twins: A European Multicenter Study

Population-based studies in twins have been of insufficient size to explore the relationship between risk of cerebral palsy and intrauterine growth. Earlier studies in singletons have suggested an optimum size at birth for minimum cerebral palsy risk between the 75th and 90th percentiles of weight for gestational age. We aggregated data from nine European cerebral palsy registers for 1976 to 1990. Using sex-specific fetal growth standards for twins, a z score of weight-for-gestation was derived for each of the 373 twin cases. The rates of cerebral palsy in each z-score band were compared to the rate in the a priori reference band of 0.67 to less than 1.28 (equivalent to the 75th to less than 90th percentiles). In twins born at 32 weeks' gestation or more (92% of all twins), cerebral palsy rates were higher for both light and heavy-forgestation babies compared to an optimum (i.e., minimum risk) in the reference band. However, the rate ratio for heavy babies (90th percentile or greater) did not reach conventional (95% confidence intervals [CI]) statistical significance (rate ratios = 1.76; 90% CI 1.02–3.03). For twins born at less than 32 weeks, the significantly higher risk for cerebral palsy was observed consistently in all z-score bands less than average compared to the reference band. This multi-center study demonstrates that for twins born at 32 weeks' gestation or more, an increased risk of cerebral palsy is associated with deviations from optimal intrauterine growth at about 1 standard deviation above mean weight, as was earlier reported for singletons. For twins born at less than 32 weeks' gestation, this pattern is only demonstrable for babies weighing below the optimum weight-for-gestation.

Neonatal morbidity in twin-twin transfusion syndrome

Twin-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies associated with high perinatal mortality and morbidity rates. Management in TTTS is a major challenge for obstetricians and neonatologists. Twins which are often born prematurely and may suffer from typical conditions associated with prematurity. In addition, surviving twins with TTTS are at increased risk for other complications including neurological, cardiovascular, renal and hematologic morbidity. Rare complications such as hypoxic-ischemic lesions to limbs or intestines and amniotic band syndrome have also been reported in TTTS survivors. This review focuses on the neonatal and pediatric mortality and morbidity in TTTS survivors, with special emphasis on the long-term neurodevelopmental outcome.

Long-term neurodevelopmental outcome in monochorionic twins after fetal therapy

Monochorionic (MC) twins are at risk for several disorders, including twin-twin transfusion syndrome (TTTS), Twin Reverse Arterial Perfusion (TRAP) and selective intrauterine growth restriction (sIUGR). Several fetal interventions, such as serial amnioreduction (AR), fetoscopic laser coagulation of placental anastomoses (FLC) and selective feticide have lead to improved perinatal morbidity and mortality rates. Nevertheless, the rate of cerebral lesions in MC twins after fetal therapy appears to be high. Follow-up studies show a high incidence of cerebral palsy (CP) and neurodevelopmental impairment (NDI). We performed a systematic review on the long-term neurodevelopmental outcome in MC twins with TTTS following AR and FLC and MC twins following selective feticide of the co-twin due to TTTS, TRAP, sIUGR and congenital anomalies.

Long-term outcome after intrauterine laser treatment for twin-twin transfusion syndrome

Twin-twin transfusion syndrome (TTTS) is a severe complication occurring in about 10% of monochorionic twin pregnancies. The chronic unbalanced transfusion of blood across placental vascular communications from the donor to the recipient twin may lead to impairment of various organ systems in the affected twins. In Hamburg, Germany, since 1995 patients with TTTS were treated with fetoscopic laser coagulation as the first causal therapeutic strategy. All survivors after laser surgery were followed up in the University Children's Hospital in Bonn, Germany. In this article, we summarize long-term follow-up studies from our German study population and compare our results with data from the literature.

Blood pressures in newborns with twin-twin transfusion syndrome

OBJECTIVE

In addition to unbalanced flow through placental anastomoses, evidence suggests that transfer of circulating vasoactive elements from the donor to the recipient contribute to the pathological process of twin-twin transfusion syndrome (TTTS). The objective of this study was to test the hypothesis that TTTS recipients have higher blood pressure (BP) at birth than donors.

STUDY DESIGN

Chart review of all TTTS infants born from 1996 to 2007 with both twins alive 24 h (51 pairs; average gestational age 30±3 weeks).

RESULTS

Both systolic and diastolic neonatal BPs were significantly higher in recipients. When expressed relative to predicted BP for birth weight (BW), BP were lower than expected in donors and higher in recipients.

CONCLUSIONS

Data indicate that TTTS recipients have BP significantly higher than donors and than BP expected for BW. The long-term impact of these early hemodynamic perturbations remains to be determined.

Prognosis and long-term neurodevelopmental outcome in conservatively treated twin-to-twin transfusion syndrome

Background

Amnioreduction remains a treatment option for pregnancies with twin-to-twin transfusion syndrome (TTTS) not meeting criteria for laser surgery or those in which it is not feasible. Amnioreduction is a relatively simple treatment which does not require sophisticated technical equipment. Previous reports of conservative management have indicated that major neurodevelopmental impairment occurs in 14.3-26% of survivors. The purpose of this study was to investigate long-term neurodevelopmental outcome in conservatively treated TTTS.

Methods

During the nine-year study period from January 1996 to December 2004, all pregnancies with TTTS who were admitted to our center were investigated. TTTS was diagnosed by using standard prenatal ultrasound criteria, and staged according to the criteria of Quintero et al. We reviewed gestational age at diagnosis, gestational age at delivery, the stage of TTTS at diagnosis, and diagnosis to delivery interval. Neonatal cranial ultrasound findings were reviewed and the neurodevelopmental outcomes were evaluated.

Results

Twenty-one pregnancies with TTTS were included. Thirteen pregnancies (62%) were treated with serial amnioreduction. The mean gestational age at delivery was 28 weeks (22 - 34 weeks). The perinatal mortality rate was 42.9%. Twenty survivors were followed up until at least 3 years of age. The mean age at follow-up was 6.3 years (3 - 12 years). Six children (30%) had neurodevelopmental impairment. Four children (20%) had major neurodevelopmental impairment and two children (10%) had minor neurodevelopmental impairment. Children with neurodevelopmental impairment were delivered before 29 weeks of gestation.

Conclusions

Our study showed a high rate of perinatal mortality and a high rate of major neurodevelopmental impairment in conservatively treated TTTS. The long-term outcomes for the survivors with TTTS were good when survivors were delivered after 29 weeks of gestation.

Neurodevelopmental outcome and risk factors for disability for twin-twin transfusion syndrome treated with laser surgery

OBJECTIVE

This study was performed to report the neurodevelopmental outcome of survivors of twin-twin transfusion syndrome (TTTS) treated with laser surgery and to determine the risk factors for neurodevelopmental disability.

STUDY DESIGN

A prospective study of TTTS cases treated with laser was performed. Survivors were assessed at 2 years corrected for prematurity. Neurodevelopmental disability was defined as the presence of cerebral palsy, deafness, blindness, or cognitive impairment with a developmental score >2 SDs below the mean.

RESULTS

A total of 75 TTTS pregnancies were treated with a perinatal survival rate of 79.3%. A total of 113 survivors were assessed. The rate of cerebral palsy was 4.4% and cognitive impairment was 8%, with a neurodevelopmental disability rate of 12.4%. Quintero stage was the only independent risk factor for neurodevelopmental disability.

CONCLUSION

The incidence of neurodevelopmental disability in TTTS survivors treated with laser is considerable, with Quintero stage being an independent risk factor.

Magnetic resonance imaging of the fetus

Fetal magnetic resonance imaging (MRI) has become established as part of clinical practice in many centres worldwide especially when visualization of the central nervous system pathology is required. In this review we summarize the recent literature and provide an overview of fetal development and the commonly encountered fetal pathologies visualized with MRI and illustrated with numerous MR images. We aim to convey the role of fetal MRI in clinical practice and its value as an additional investigation alongside ultrasound yet emphasize the need for caution when interpreting fetal MR images especially where experience is limited.

Specific complications of monochorionic twin pregnancies: twin-twin transfusion syndrome and twin reversed arterial perfusion sequence

Monochorionic twins are subjected to specific complications which originate in either imbalance or abnormality of the single placenta serving two twins. This unequal placental sharing can cause complications including twin-twin transfusion syndrome (TTTS), twin anemia-polycythemia sequence (TAPS), selective intrauterine growth restriction or twin reversed arterial perfusion sequence (TRAP). Monochorionicity also makes the management of these specific complications as well as that of a severe malformation in one twin hazardous since the spontaneous death of one twin exposes the co-twin to a risk of exsanguination into the dead twin and its placenta. The latter is responsible for the death of the co-twin in up to 20% of the cases and in ischemic sequelae in about the same proportions in the survivors. Although the symptoms of all these complications are very different, the keystone of their management comes down to either surgical destruction of the inter-twin anastomoses on the chorionic plate when aiming at dual survival or selective and permanent occlusion of the cord of a severely affected twin aiming at protecting the normal co-twin. This can be best achieved by fetoscopic selective laser coagulation and bipolar forceps cord coagulation respectively.

Long-term developmental follow-up of infants who participated in a randomized clinical trial of amniocentesis vs laser photocoagulation for the treatment of twin-to-twin transfusion syndrome

OBJECTIVE

We sought to assess long-term neurodevelopment of children who were treated prenatally as part of the Eurofoetus randomized controlled trial.

STUDY DESIGN

The study population was composed of 128 cases of twin-to-twin transfusion syndrome (TTTS) included and followed up in France. Survivors were evaluated by standardized neurological examination and by Ages and Stages Questionnaires (ASQ). Primary outcome was a composite of death and major neurological impairment.

RESULTS

A total of 120 children (47%) were alive at the age of 6 months and were followed up to the age of 6 years. At the time of diagnosis, only treatment and Quintero stage were predictors of a poor outcome (hazard ratio, 0.61; 95% confidence interval, 0.41-0.90; P = .01 and hazard ratio, 3.23; 95% confidence interval, 2.19-4.76; P < .001, respectively). Children treated by fetoscopic selective laser coagulation (FSLC) had higher ASQ scores at the end of follow-up (P = .04).

CONCLUSION

FSLC was significantly associated with a reduction of the risk of death or long-term major neurological impairment at the time of diagnosis and treatment.

Clinical outcome in neonates with twin anemia-polycythemia sequence

OBJECTIVE

The purpose of this study was to evaluate neonatal outcome of monochorionic twin pregnancies complicated by twin anemia-polycythemia sequence (TAPS).

STUDY DESIGN

A cohort of consecutive monochorionic twins with TAPS with double survivors was included in the study. Each twin pair with TAPS was compared with 2 monochorionic twin pairs who were unaffected by TAPS or twin-to-twin transfusion syndrome and who were matched for gestational age at birth. Neonatal death, severe morbidity, and cerebral injury were studied.

RESULTS

We included 19 twin pairs in the TAPS group and 38 control twin pairs. The incidence of neonatal death and severe neonatal morbidity was similar in the TAPS group and control group (3% [1/38] vs 1% [1/76] and 24% [9/38] vs 28% [21/76], respectively). Severe cerebral injury was detected in 1 infant (5%) in the TAPS group and 1 infant (2%) in the control group.

CONCLUSION

Neonatal mortality and morbidity rates in a select population of TAPS neonates are similar to control neonatal rates.

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

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

Long-term neurodevelopmental outcome of monochorionic and matched dichorionic twins

BACKGROUND

Monochorionic (MC) twins are at increased risk for perinatal mortality and serious morbidity due to the presence of placental vascular anastomoses. Cerebral injury can be secondary to haemodynamic and hematological disorders during pregnancy (especially twin-to-twin transfusion syndrome (TTTS) or intrauterine co-twin death) or from postnatal injury associated with prematurity and low birth weight, common complications in twin pregnancies. We investigated neurodevelopmental outcome in MC and dichorionic (DC) twins at the age of two years.

METHODS

This was a prospective cohort study. Cerebral palsy (CP) was studied in 182 MC infants and 189 DC infants matched for weight and age at delivery, gender, ethnicity of the mother and study center. After losses to follow-up, 282 of the 366 infants without CP were available to be tested with the Griffiths Mental Developmental Scales at 22 months corrected age, all born between January 2005 and January 2006 in nine perinatal centers in The Netherlands. Due to phenotypic (un)alikeness in mono-or dizygosity, the principal investigator was not blinded to chorionic status; perinatal outcome, with exception of co-twin death, was not known to the examiner.

FINDINGS

Four out of 182 MC infants had CP (2.2%) - two of the four CP-cases were due to complications specific to MC twin pregnancies (TTTS and co-twin death) and the other two cases of CP were the result of cystic PVL after preterm birth - compared to one sibling of a DC twin (0.5%; OR 4.2, 95% CI 0.5-38.2) of unknown origin. Follow-up rate of neurodevelopmental outcome by Griffith's test was 76%. The majority of 2-year-old twins had normal developmental status. There were no significant differences between MC and DC twins. One MC infant (0.7%) had a developmental delay compared to 6 DC infants (4.2%; OR 0.2, 95% 0.0-1.4). Birth weight discordancy did not influence long-term outcome, though the smaller twin had slightly lower developmental scores than its larger co-twin.

CONCLUSIONS

There were no significant differences in occurrence of cerebral palsy as well as neurodevelopmental outcome between MC and DC twins. Outcome of MC twins seems favourable in the absence of TTTS or co-twin death.

Selective laser photocoagulation versus serial amniodrainage for the treatment of twin-twin transfusion syndrome: a cost-effectiveness analysis

OBJECTIVE

To compare the cost-effectiveness of selective laser photocoagulation (SLP) with serial amniodrainage (AD) in the treatment of twin-to-twin transfusion syndrome (TTTS).

STUDY DESIGN

Using decision-analysis modeling, we compared the cost-effectiveness of using laser photocoagulation with AD for the treatment of TTTS. The analysis was carried out from a societal perspective using a theoretical cohort of 1000 women with TTTS. Costs included the costs of procedures, perinatal complications from TTTS and of resources used for raising a child with cerebral palsy (CP) following TTTS. One-way, multiway and probabilistic (Monte Carlo) sensitivity analyses were carried out for all model variables. The main outcome measures were: cost per quality-adjusted life years (QALYs) gained from treating TTTS.

RESULT

On the basis of the available data, the decision model favors SLP as the most cost-effective treatment option compared with AD. Using the theoretical cohort, laser photocoagulation will result in an overall perinatal survival of 59.3% compared with 51.5% for AD. The frequency of children with CP after laser would be 8.5% compared with 15.4% after AD. Sensitivity analyses showed the model to be robust over a wide range of values for the variables, except when the overall survival associated with AD is >62%. Above that survival rate, AD was the more cost-effective therapy.

CONCLUSION

Under a wide range of circumstances, the most cost-effective therapy for TTTS is SLP.

Twinning on the brain: the effect on neurodevelopmental outcomes

Twinning is currently considered a complex multifactorial trait. Few studies have explored how the unique genetic and environmental influences that create twinning affect phenotypes and outcomes. Previous data has shown that twins account for a significant proportion of preterm and low-birth-weight infants, who are at risk for long-term neurodevelopmental disabilities such as cerebral palsy and cognitive impairment. More recently, it has been postulated that even without these co-morbidities, twinning in and of itself may incur a neurodevelopmental disadvantage even among term newborns. The purpose of this review is to report primarily on neuromotor outcomes of twins compared to singletons. In addition, we describe specific environmental risk factors among twins which are associated with poorer outcomes. Several putative neurodevelopmental modulators are explored, including death of a co-twin, chorionicity, birth weight discordance, and twin-twin transfusion. By teasing out environmental influences that potentially influence neurocognitive outcomes, families can receive more specific counseling and developmental services can be provided to those twins at especially high risk.

Twin-to-twin transfusion syndrome: a comprehensive update

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

The pregnancy and long-term neurodevelopmental outcome of monochorionic diamniotic twin gestations: a multicenter prospective cohort study from the first trimester onward

OBJECTIVES

We sought to document the pregnancy and neurodevelopmental outcome in monochorionic diamniotic twin pregnancies and to identify risk factors for death and impairment.

STUDY DESIGN

We conducted a prospective cohort study of 136 monochorionic twins followed up from the first trimester until infancy.

RESULTS

A total of 122 (90%) pregnancies resulted in 2 survivors, 6 (4%) in 1 survivor and 8 (6%) in no survivor. In all, 230 (92%) of 250 surviving infants were assessed at a mean age of 24 months. Neurodevelopmental impairment was present in 22 (10%) infants. Death or impairment of 1 or both infants occurred in 28 (22%) of 126 pregnancies. Twin-to-twin transfusion syndrome and assisted conception increased the risk of both death and impairment, whereas early-onset discordant growth only increased the risk of death.

CONCLUSION

The mortality in this prospective series was 8% and neurodevelopmental impairment occurred in 10% of infants.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cerebral injury in monochorionic twins with selective intrauterine growth restriction and/or birthweight discordance

OBJECTIVE

The objective of the study was to study the incidence of severe cerebral injury in monochorionic (MC) twins with selective intrauterine growth restriction (sIUGR) and/or birthweight discordance.

STUDY DESIGN

All MC twin pregnancies with 2 liveborn twins were included in the study. We excluded all cases with twin-to-twin transfusion syndrome (TTTS). Sequential cranial ultrasound scans were performed in all MC twin infants.

RESULTS

A total of 117 MC twin pairs were included in the study. The sIUGR of at least 1 fetus was found in 50 twin pregnancies (43%), and birthweight discordance of 25% or greater occurred in 26 twin pregnancies (22%). The overall incidence of severe cerebral injury was 3% (6/218). The incidence of severe cerebral injury in infants from twin pregnancies with and without sIUGR was 2% (2/94) and 3% (4/124), respectively (P = .62). The incidence of severe cerebral injury in infants with and without birthweight discordance was 0% (0/48) and 4% (6/170), respectively (P = .19).

CONCLUSION

The incidence of severe cerebral injury in MC twin pregnancies not complicated by TTTS with 2 liveborn twins is low. No association could be demonstrated with sIUGR or intertwin birthweight discordance of 25% or greater.