Perinatal outcome of pregnancy complicated by twin anemia-polycythemia sequence: systematic review and meta-analysis.

OBJECTIVE: To report the perinatal outcome of monochorionic diamniotic (MCDA) twin pregnancies complicated by twin anemia-polycythemia sequence (TAPS), according to the type of TAPS (spontaneous or postlaser) and the management option adopted. METHODS: MEDLINE, EMBASE and The Cochrane Library databases were searched for studies reporting on the outcome of twin pregnancies complicated by TAPS. Inclusion criteria were non-anomalous MCDA twin pregnancies with a diagnosis of TAPS. The primary outcome was perinatal mortality; secondary outcomes were neonatal morbidity and preterm birth (PTB). The outcomes were stratified according to the type of TAPS (spontaneous or following laser treatment for twin-twin transfusion syndrome) and the management option adopted (expectant, laser surgery, intrauterine transfusion (IUT) or selective reduction (SR)). Random-effects meta-analysis of proportions was used to analyze the data. RESULTS: Perinatal outcome was assessed according to whether TAPS occurred spontaneously or after laser treatment in 506 pregnancies (38 studies). Intrauterine death (IUD) occurred in 5.2% (95% CI, 3.6-7.1%) of twins with spontaneous TAPS and in 10.2% (95% CI, 7.4-13.3%) of those with postlaser TAPS, while the corresponding rates of neonatal death were 4.0% (95% CI, 2.6-5.7%) and 9.2% (95% CI, 6.6-12.3%), respectively. Severe neonatal morbidity occurred in 29.3% (95% CI, 25.6-33.1%) of twins after spontaneous TAPS and in 33.3% (95% CI, 17.4-51.8%) after postlaser TAPS, while the corresponding rates of severe neurological morbidity were 4.0% (95% CI, 3.5-5.7%) and 11.1% (95% CI, 6.2-17.2%), respectively. PTB complicated 86.3% (95% CI, 77.2-93.3%) of pregnancies with spontaneous TAPS and all cases with postlaser TAPS (100% (95% CI, 84.3-100%)). Iatrogenic PTB was more frequent than spontaneous PTB in both groups. Perinatal outcome was assessed according to the management option adopted in 417 pregnancies (21 studies). IUD occurred in 9.8% (95% CI, 4.3-17.1%) of twins managed expectantly and in 13.1% (95% CI, 9.2-17.6%), 12.1% (95% CI, 7.7-17.3%) and 7.6% (95% CI, 1.3-18.5%) of those treated with laser surgery, IUT and SR, respectively. Severe neonatal morbidity affected 27.3% (95% CI, 13.6-43.6%) of twins in the expectant-management group, 28.7% (95% CI, 22.7-35.1%) of those in the laser-surgery group, 38.2% (95% CI, 18.3-60.5%) of those in the IUT group and 23.3% (95% CI, 10.5-39.2%) of those in the SR group. PTB complicated 80.4% (95% CI, 59.8-94.8%), 73.4% (95% CI, 48.1-92.3%), 100% (95% CI, 76.5-100%) and 100% (95% CI, 39.8-100%) of pregnancies after expectant management, laser surgery, IUT and SR, respectively. CONCLUSIONS: The present meta-analysis provides pooled estimates of the risks of perinatal mortality, neonatal morbidity and PTB in twin pregnancies complicated by TAPS, stratified by the type of TAPS and the management option adopted. Although a direct comparison could not be performed, the results from this systematic review suggest that spontaneous TAPS may have a better prognosis than postlaser TAPS. No differences in terms of mortality and morbidity were observed when comparing different management options for TAPS, although these findings should be interpreted with caution in view of the limitations of the included studies. Individualized prenatal management, taking into account the severity of TAPS and gestational age, is currently the recommended strategy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Perinatal outcomes of iatrogenic chorioamniotic separation following fetoscopic surgery: systematic review and meta-analysis.

OBJECTIVE: To compare the perinatal outcomes between pregnancies with and those without iatrogenic chorioamniotic separation (iCAS) following fetoscopic intervention. METHODS: We performed a search in PubMed, EMBASE, Scopus, Web of Science and Google Scholar from inception up to December 2020 for studies comparing perinatal outcomes between pregnancies that developed and those that did not develop iCAS after fetoscopic intervention for twin-to-twin transfusion syndrome (TTTS), open neural tube defect (ONTD) or congenital diaphragmatic hernia. A random-effects model was used to pool the mean differences (MD) or odds ratios (OR) and the corresponding 95% CI. The primary outcome was neonatal survival. Secondary outcomes included gestational age (GA) at intervention and at delivery, interval from intervention to delivery and incidence of preterm prelabor rupture of membranes (PPROM) and preterm delivery. The methodological quality of the included studies was evaluated using the Newcastle-Ottawa scale. RESULTS: The search identified 348 records, of which seven studies (six on fetoscopic laser photocoagulation (FLP) for TTTS and one on fetoscopic repair for ONTD) assessed the perinatal outcomes of pregnancies that developed iCAS after fetoscopic intervention. Given that only one study reported on fetoscopic ONTD repair, the meta-analysis was limited to TTTS pregnancies and included six studies (total of 1881 pregnancies). Pregnancies that developed iCAS after FLP for TTTS, compared with those that did not, had significantly lower GA at the time of intervention (weeks) (MD, -1.07 (95% CI, -1.89 to -0.24); P = 0.01) and at delivery (weeks) (MD, -1.74 (95% CI, -3.13 to -0.34); P = 0.01) and significantly lower neonatal survival (OR, 0.41 (95% CI, 0.24-0.70); P = 0.001). In addition, development of iCAS after FLP for TTTS increased significantly the risk for PPROM < 34 weeks' gestation (OR, 3.98 (95% CI, 1.76-9.03); P < 0.001) and preterm delivery < 32 weeks (OR, 1.80 (95% CI, 1.16-2.80); P = 0.008). CONCLUSIONS: iCAS is a common complication after FLP for TTTS. In patients undergoing FLP for TTTS, iCAS develops more often with earlier GA at intervention and is associated with earlier GA at delivery, higher risk of PPROM < 34 weeks' gestation and preterm delivery < 32 weeks and lower neonatal survival. Given the limitations of this meta-analysis and lack of literature reporting on other types of fetoscopic intervention, the presented findings should be interpreted with caution and should not be generalized to fetoscopic procedures used to treat other fetal conditions. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

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.

Fetal cardiac filling and ejection time fractions by pulsed-wave Doppler: reference ranges and potential clinical application.

OBJECTIVES: Fetal cardiac function can be evaluated using a variety of parameters. Among these, cardiac cycle time-related parameters, such as filling time fraction (FTF) and ejection time fraction (ETF), are promising but rarely studied. We aimed to report the feasibility and reproducibility of fetal FTF and ETF measurements using pulsed-wave Doppler, to provide reference ranges for fetal FTF and ETF, after evaluating their relationship with heart rate (HR), gestational age (GA) and estimated fetal weight (EFW), and to evaluate their potential clinical utility in selected fetal conditions. METHODS: This study included a low-risk prospective cohort of singleton pregnancies and a high-risk population of fetuses with severe twin-twin transfusion syndrome (TTTS), aortic stenosis (AoS) or aortic coarctation (CoA), from 18 to 41 weeks' gestation. Left ventricular (LV) and right ventricular inflow and outflow pulsed-wave Doppler signals were analyzed, using valve clicks as landmarks. FTF was calculated as: (filling time/cycle time) × 100. ETF was calculated as: (ejection time/cycle time) × 100. Intraclass correlation coefficients (ICC) were used to evaluate the intra- and interobserver reproducibility of FTF and ETF measurements in low-risk fetuses. The relationships of FTF and ETF with HR, GA and EFW were evaluated using multivariate regression analysis. Reference ranges for FTF and ETF were then constructed using the low-risk population. Z-scores of FTF and ETF in the high-risk fetuses were calculated and analyzed. RESULTS: In total, 602 low-risk singleton pregnancies and 54 high-risk fetuses (nine pairs of monochorionic twins with severe TTTS, 16 fetuses with AoS and 20 fetuses with CoA) were included. Adequate Doppler traces for FTF and ETF could be obtained in 95% of low-risk cases. Intraobserver reproducibility was good to excellent (ICC, 0.831-0.905) and interobserver reproducibility was good (ICC, 0.801-0.837) for measurements of all timing parameters analyzed. Multivariate analysis of FTF and ETF in relation to HR, GA and EFW in low-risk fetuses identified HR as the only variable predictive of FTF, while ETF was dependent on both HR and GA. FTF increased with decreasing HR in low-risk fetuses, while ETF showed the opposite behavior, decreasing with decreasing HR. Most recipient twins with severe TTTS showed reduced FTF and preserved ETF. AoS was associated with decreased FTF and increased ETF in the LV, with seemingly different patterns associated with univentricular vs biventricular postnatal outcome. The majority of fetuses with CoA had FTF and ETF within the normal range in both ventricles. CONCLUSIONS: Measurement of FTF and ETF using pulsed-wave Doppler is feasible and reproducible in the fetus. The presented reference ranges account for associations of FTF with HR and of ETF with HR and GA. These time fractions are potentially useful for clinical monitoring of cardiac function in severe TTTS, AoS and other fetal conditions overloading the heart. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Antenatal management and neonatal outcomes of monochorionic twin pregnancies in a tertiary teaching hospital: a 10-year review.

Monochorionic (MC) pregnancy is a high risk pregnancy with well-defined specific complications, such as twin-to-twin transfusion syndrome (TTTS) and twin anaemia-polycythaemia sequence (TAPS). Laser photocoagulation (LPC) is an effective treatment for both complications. In the current retrospective study, we determined the incidence of MC pregnancy complications in a tertiary care centre during a 10-year period. Single foetal death (FD) beyond 14 weeks' gestation was significantly higher when complicated by either TTTS, TAPS or selective foetal growth restriction (21.4%, 16.7% and 9.1% versus 1.6%, p<.001, p=.02 and p=.04, respectively). We also demonstrated that twins' weight discordance >20% is an independent risk factor for single or double FD after LPC. Consequently, prior to LPC, patients should be counselled that early diagnosis of TTTS, advanced Quintero stages and weight discordances >20% are potential risk factors for FD. Further studies are needed to identify additional risk factors for TTTS and TAPS outcome after LPC.Impact StatementWhat is already known on this subject? Monochorionic (MC) pregnancy is a high risk pregnancy with well-defined specific complications, such as twin-twin transfusion syndrome (TTTS) and twin anaemia-polycythaemia sequence (TAPS). Laser photocoagulation (LPC) is an effective treatment for both complications.What the results of this study add? The results of the current study determined the incidence of MC pregnancy complications in a tertiary care centre in Brussels, and identified that twins' weight discordance >20% is an independent risk factor for single or double foetal death after LPC.What the implications are of these findings for clinical practice and/or further research? Prior to laser coagulation, patients should be counselled that early diagnosis of TTTS, Quintero stages 3 or 4 and weight discordances >20% are potential risk factors for foetal demise. Further studies are needed to identify additional risk factors for TTTS and TAPS outcome after LPC.

Predisposing factors and neonatal outcomes for twin-twin transfusion syndrome cases developing transient donor hydrops after fetoscopic laser coagulation: a case control study.

BACKGROUND: Transient donor hydrops (TDH) is defined as donor hydrops developed within days after laser therapy for twin-twin transfusion syndrome (TTTS) followed by resolution later. The purpose of this study was to evaluate the incidence, neonatal outcomes and predisposing factors of post laser therapy TDH in severe TTTS. METHODS: A total of 142 patients with severe TTTS who received laser therapy were included into this study. The pre-operative characteristics and neonatal outcomes were compared between TTTS with and without post laser therapy TDH. All live neonates received cranial ultrasound examination after delivery, mild cerebral injury was defined as exhibiting at least one of the following: intraventricular hemorrhage (IVH) grade I and II, lenticulostriate vasculopathy and subependymal pseudocysts; severe cerebral injury comprised at least one among the following: IVH grade III or grade IV, cystic periventriculoleukomalacia (PVL) grade II or more, porencephalic cysts, and ventricular dilatation. Fetal survival was defined as living more than 30 days after delivery.

Cardiac pathophysiology in twin-twin transfusion syndrome: new insights into its evolution.

OBJECTIVES: In twin-twin transfusion syndrome (TTTS), unbalanced transfer of vasoactive mediators and fluid from the donor to the recipient cotwin alters their cardiovascular function. The aims of this study were to describe the impact of TTTS on fetal cardiac function in a large cohort of monochorionic-diamniotic (MCDA) pregnancies, and determine the early hemodynamic response to selective fetoscopic laser photocoagulation (SFLP). METHODS: Echocardiography was performed in 145 MCDA pregnancies, including 26 uncomplicated MCDA, 61 TTTS Stages I+II and 58 TTTS Stages III+IV pregnancies, prior to SFLP for TTTS. Echocardiographic data after SFLP were available in a subset of 41/119 (34%) TTTS cases at a mean of 1.7 ± 1.9 days. Mitral (MAPSE) and tricuspid (TAPSE) annular systolic excursion, myocardial performance index (MPI), tissue Doppler velocities (E', A', S') and filling pressures (E/E') were measured and transformed into Z-scores. Ventricular pressure was estimated from peak atrioventricular regurgitation velocity. RESULTS: Left ventricular hemodynamics of the recipient twin were affected in early TTTS. In all stages of TTTS, left MPI and E/E' of the recipient twin were elevated in comparison to those of the donor (all P < 0.05), with reduced recipient left S' in TTTS Stages III+IV (P < 0.001). Ventricular pressure was elevated for gestational age (median, 42 mmHg (range, 20-65 mmHg)) in 11 of 14 recipients in which this parameter was measured. Between-group difference in right ventricular E/E' was significant only in TTTS Stages III+IV recipients compared with TTTS Stages I+II (P = 0.007) and uncomplicated MCDA (P = 0.041). Recipient left and right MPI decreased while S', MAPSE and TAPSE increased after SFLP; in donors, left E/E' and cardiac output increased. CONCLUSIONS: Cardiac function of the recipient twin in TTTS is abnormal, even in the early stages of the disease. Left ventricular filling pressures are elevated and systolic function is decreased before abnormalities in the right heart become apparent. SFLP produces rapid hemodynamic improvement. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Time-interval analysis of ductus venosus flow velocity waveforms in twin-to-twin transfusion syndrome treated with laser surgery.

OBJECTIVES: To investigate time-interval variables of ductus venosus (DV) flow velocity waveforms (FVWs) in twin-to-twin transfusion syndrome (TTTS), comparing the results with reference ranges from normal singleton fetuses. The impact of laser surgery and the effect of prognostic factors were also evaluated. METHODS: In 107 TTTS cases, DV-FVWs of both recipients and donors were recorded 1 day before and 2 days after laser therapy. Time intervals for systolic (S) and early diastolic (D) peaks were analyzed retrospectively with regard to acceleration time (acc-S and acc-D for S and D, respectively) and deceleration time (dec-S and dec-D for S and D, respectively). For each variable, Z-scores were calculated with respect to previously reported normal reference ranges. RESULTS: Z-scores for all variables showed statistically significant differences from those observed previously in normal fetuses, with the exception of dec-S of donors. The most striking differences were observed in longer dec-S of recipients (P < 0.001) and longer dec-D of donors (P < 0.001). Laser therapy showed significant impact on dec-S and acc-D in recipients and on all variables in donors. Regarding the short-term prognosis, acc-S and dec-S showed significant differences for the prediction of intrauterine fetal demise in donors (P = 0.009 and P = 0.011, respectively). CONCLUSION: This study demonstrates that time-interval variables of DV-FVWs may differentiate the characteristic hemodynamic changes caused by unbalanced blood volume between recipients and donors.

Single fetal demise in monochorionic pregnancies: incidence and patterns of cerebral injury.

OBJECTIVE: To evaluate the incidence, type and severity of cerebral injury in the surviving monochorionic (MC) cotwin after single fetal demise in twin pregnancies. METHODS: All MC pregnancies with single fetal demise that were evaluated at the Leiden University Medical Center between 2002 and 2013 were included. Perinatal characteristics, neonatal outcome and the presence of cerebral injury, observed on neuroimaging, were recorded for all cotwin survivors. RESULTS: A total of 49 MC pregnancies with single fetal demise, including one MC triplet, were included in the study (n = 50 cotwins). Median gestational age at occurrence of single fetal demise was 25 weeks and median interval between single fetal demise and live birth was 61 days, with a median gestational age at birth of 36 weeks. Severe cerebral injury was diagnosed in 13 (26%) of the 50 cotwins and was detected antenatally in 4/50 (8%) and postnatally in 9/50 (18%) cases. Cerebral injury was mostly due to hypoxic-ischemic injury resulting in cystic periventricular leukomalacia, middle cerebral artery infarction or injury to basal ganglia, thalamus and/or cortex. Risk factors associated with severe cerebral injury were advanced gestational age at the occurrence of single fetal demise (odds ratio (OR), 1.14 (95% CI, 1.01-1.29) for each week of gestation; P = 0.03), twin-twin transfusion syndrome developing prior to single fetal demise (OR, 5.0 (95% CI, 1.30-19.13); P = 0.02) and a lower gestational age at birth (OR, 0.83 (95% CI, 0.69-0.99) for each week of gestation; P = 0.04). CONCLUSIONS: Single fetal demise in MC pregnancies is associated with severe cerebral injury occurring in 1 in 4 surviving cotwins. Routine antenatal and postnatal neuroimaging, followed by standardized long-term follow-up, is mandatory.

Twin-twin transfusion syndrome: a frequently missed diagnosis with important consequences.

OBJECTIVE: To evaluate the incidence and consequences of 'misdiagnosed' cases of twin-twin transfusion syndrome (TTTS). METHODS: Chorionicity and referral diagnoses were reviewed in pregnant women with monochorionic twin pregnancies complicated by TTTS treated with fetoscopic laser ablation. 'Misdiagnosed' cases, defined as failure to correctly identify chorionicity and/or to diagnose TTTS prior to referral, were compared with cases in whom chorionicity and TTTS were diagnosed correctly. TTTS stage, gestational age at referral, overall survival, fetal and perinatal mortality, gestational age at delivery, operating time and maternal complications were compared. RESULTS: Failure to identify monochorionicity and/or TTTS was observed in 33% (107/323) of referrals to our center. Compared with cases in whom chorionicity and TTTS were correctly diagnosed, misdiagnosed patients were referred at a more advanced stage of disease (Stage IV TTTS: 16.8% vs 7.9%, P = 0.014) and later in pregnancy (gestational age at laser: 20.9 weeks vs 20.1 weeks, P = 0.018). They also delivered more prematurely (30.3 weeks' gestation vs 31.5 weeks' gestation, P = 0.04) and fetal and neonatal mortality were higher (neonatal death within 7 days: 19.6% vs 6.0%, P < 0.001). When the diagnosis was incorrect, major maternal complications and intensive care unit admissions were increased. CONCLUSIONS: Poor recognition of chorionicity in the first trimester of pregnancy might lead to inadequate ultrasound follow up (failure to assess every 2 weeks) and patient education. Early accurate recognition of both chorionicity and TTTS, with timely referral to a fetal therapy center, are key to ensuring optimal maternal and fetal outcomes.

Functional echocardiography in the fetus with non-cardiac disease.

We describe the hemodynamic changes observed in fetuses with extra cardiac conditions such as intrauterine growth restriction, tumors, twin-twin transfusion syndrome, congenital infections, and in fetuses of mothers with diabetes. In most fetuses with mild extra cardiac disease, the alterations in fetal cardiac function remain subclinical. Cardiac function assessment has however helped us to achieve a better understanding of the pathophysiology of these diseases. In fetuses at the more severe end of the disease spectrum, functional echocardiography may help in guiding clinical decision-making regarding the need for either delivery or fetal therapy. The growth-restricted fetus represents a special indication for routine cardiac function assessment, as in utero hemodynamic changes may help optimize the timing of delivery. Moreover, in intrauterine growth restriction, the altered hemodynamics causes cardiovascular remodeling, which can result in an increased risk of postnatal cardiovascular disease.

Twin reversed arterial perfusion sequence: a new method of parabiotic twin mass estimation correlated with pump twin compromise.

OBJECTIVES: The purpose of this study was to test the hypothesis that using the formula of a prolate ellipsoid to estimate parabiotic twin mass correlates better with findings of pump twin compromise than using the sonographic method of Moore et al (Am J Obstet Gynecol 1990; 163:907-912). METHODS: A 10-year retrospective review was performed to identify all cases of the suspected twin reversed arterial perfusion (TRAP) sequence. Parabiotic twin mass was estimated by summing body and extremity volumes calculated using the prolate ellipsoid formula (width × height × length × 0.523). Parabiotic twin mass was also estimated using the sonographic Moore method [1.21 × length(2) - (1.66 × length)]. Parabiotic twin mass estimated by both methods was correlated with sonographic findings associated with increased risk of pump twin compromise. RESULTS: Fifty-nine pregnancies complicated by TRAP were identified. Using the prolate ellipsoid formula, the parabiotic twin mean sizes ± SD (as a percentage of pump twin weight) were 103.0% ± 52.0% and 56.9% ± 44.3% in cases with and without pump twin compromise (P = .0005), respectively. Using the sonographic Moore method, the mean parabiotic twin sizes were 122.9% ± 54.3% and 99.6% ± 62.8% in cases with and without pump twin compromise (P = .14). The median estimated masses of the parabiotic twin were 197 ± 219 g using the prolate ellipsoid formula and 310 ± 212 g using the sonographic Moore method (P = .0001). A parabiotic twin size greater than 70% of the pump twin correlated with findings associated with increased risk of pump twin compromise when using the prolate ellipsoid formula (P = .002) but not the sonographic Moore method (P = .09). CONCLUSIONS: Sonographic findings associated with increased risk of pump twin compromise correlate better with prolate ellipsoid estimates of parabiotic twin mass. The median estimated mass of the parabiotic twin was statistically larger when calculated by the sonographic Moore method than by the prolate ellipsoid formula.

Prevalence and progression of recipient-twin cardiomyopathy in early-stage twin-twin transfusion syndrome.

OBJECTIVE: The management of twin-twin transfusion syndrome (TTTS) in its early stages (Quintero Stages I and II) is controversial. We describe the prevalence, severity, incidence and rate of progression of recipient-twin cardiomyopathy in Stages I and II TTTS. METHODS: Among 451 cases of TTTS evaluated between 2004 and 2009, 123 (27.3%) cases of Stages I and II were reviewed. Echocardiography was used to 'upstage' cases based on the presence or absence of mild (IIIA), moderate (IIIB), or severe (IIIC) recipient cardiomyopathy. Progression was defined by worsening in the degree of recipient-twin cardiomyopathy from initial presentation or failure to respond to amnioreduction. Outcome data included progression of recipient-twin cardiomyopathy, treatment and survival to birth. Data were compared by the chi-square, Fisher's exact test or t-test as appropriate. RESULTS: Seventy-seven of 123 (62.6%) cases were Quintero Stage I and 46/123 (37.4%) Quintero Stage II. Eighty (65.0%) were upstaged to Cincinnati Stage IIIA (n = 25), IIIB (n = 23) or IIIC (n = 32). Management included observation in 11 (8.9%), amnioreduction in 26 (21.1%), amnioreduction followed by selective fetoscopic laser photocoagulation (SFLP) in 43 (35.0%) and primary SFLP in 43 (35.0%). Of 80 cases managed by observation or amnioreduction initially, 43 (53.8%) progressed within a mean duration of 1.4 ± 1.5 weeks. The incidence of progression increased significantly as degree of recipient-twin cardiomyopathy at presentation worsened: Stage I, 9/27 (33.3%); Stage II, 8/15 (53.3%); Stage IIIA, 8/16 (50.0%); Stage IIIB, 10/10 (100%); and Stage IIIC, 8/12 (66.7%) (χ(2) = 14, P < 0.01). Overall fetal survival was 205 out of 244 (84.0%). Fetal survival with observation only was 81.8% (18/22), with amnioreduction only it was 92.3% (48/52), with initial observation or amnioreduction followed by SFLP it was 86.9% (73/84) and with primary SFLP it was 76.7% (66/86). CONCLUSION: Echocardiography demonstrates a high incidence of recipient-twin cardiomyopathy in early-stage TTTS. The more advanced the recipient-twin cardiomyopathy is, the more likely is progression to occur during observation or following amnioreduction.

Limb constriction secondary to pseudoamniotic band syndrome after selective fetoscopic laser surgery: report of a case with a favorable outcome.

Pseudoamniotic band syndrome (PABS) is an iatrogenic complication that causes entanglement of fetal parts in a constrictive sheet of detached or ruptured amniotic membrane after an invasive procedure, namely amniocentesis, amnioreduction or septostomy in twins. The incidence and risk factors for PABS after fetoscopy-guided laser have not been documented [Winer et al.: Am J Obstet Gynecol 2008;198:393.e1-393.e5]. We report a case of monochorionic biamniotic twin pregnancy submitted to selective fetoscopic laser photocoagulation for twin-to-twin transfusion syndrome at 16 weeks of gestation. The procedure was complicated by the death of one of the fetuses at 24 weeks of gestation. Moreover, the surviving twin was diagnosed postnatally with pseudoamniotic band syndrome, presenting with affected limbs. The newborn was submitted to surgical correction of these lesions with a successful outcome and was discharged on day 15.

Fetal cardiac function: technical considerations and potential research and clinical applications.

Fetal echocardiography was initially used to detect structural anomalies but has more recently also been proposed to assess fetal cardiac function. This review summarizes technical issues and limitations in fetal cardiac function evaluation, as well as its potential research and clinical applications. Functional echocardiography has been demonstrated to select high-risk populations and to be associated with outcome in several fetal conditions including intrauterine growth restriction, twin-to-twin transfusion syndrome, maternal diabetes, and congenital diaphragmatic hernia. Fetal heart evaluation is challenging due to the smallness and high heart rate of the fetus and restricted access to the fetus far from the transducer. Due to these limitations and differences in cardiac function which are related to fetal maturation, cardiovascular parameters should be validated in the fetus and used with caution. Despite these precautions, in expert hands and with appropriate ultrasound equipment, evaluation of cardiac function is feasible in most fetuses. Functional fetal echocardiography is a promising tool that may soon be incorporated into clinical practice. Research is warranted to further refine the contribution of fetal cardiac assessment to the diagnosis, monitoring, or prediction of outcomes in various fetal conditions.

Speckle tracking-derived myocardial tissue deformation imaging in twin-twin transfusion syndrome: differences in strain and strain rate between donor and recipient twins.

OBJECTIVES: Twin-twin transfusion syndrome (TTTS) is a complex disorder with altered cardiovascular loading conditions that affects both donors and recipients. Myocardial tissue deformation analysis using vector velocity imaging is an angle-independent, speckle-tracking technique which can assess myocardial mechanics and may provide insight into cardiac dysfunction in TTTS. METHODS: Digital dynamic two-dimensional four-chamber views were interrogated offline. Images were acquired utilizing standard video frame rates (30 frames/s). The global longitudinal strain, systolic strain rate, and diastolic strain rate were measured in the left (LV) and right ventricles (RV) of 25 fetal pairs with TTTS and compared to 25 gestational age-matched normal controls. Pulsatility indices for the umbilical artery and middle cerebral artery were measured. RESULTS: The gestational age at evaluation was 20.5 ± 1.3 weeks. The donor LV systolic strain rate was higher, while the donor RV diastolic strain rate was significantly lower, than control values. The recipient longitudinal strain, systolic strain rate, and diastolic strain rate were significantly lower for both LV and RV in comparison to controls. The donor umbilical artery pulsatility index was higher than control values (1.92 ± 0.45 vs. 1.41 ± 0.25, p < 0.001), while the donor middle cerebral artery pulsatility index was lower (1.46 ± 0.28 vs. 1.87 ± 0.21). Recipient umbilical artery and middle cerebral artery pulsatility indices were no different than control values. CONCLUSIONS: In TTTS, both the donor and the recipient exhibit abnormalities of myocardial tissue deformation with ventricle-specific changes evident based on loading conditions. Donor LV systolic function is hyperdynamic due to hypovolemia and selective ejection into a low-resistance cerebrovascular circuit while the donor RV selectively ejects into a high-resistance placental circuit. Recipient RV and LV are both globally depressed with systolic and diastolic dysfunction. Further prospective validation of our findings using high frame rate analysis is indicated.

Twin reversed arterial perfusion syndrome in a monochorionic monoamniotic twin pregnancy.

OBJECTIVE: Twin-Reversed Arterial Perfusion (TRAP) sequence is a rare complication of monochorionic multiple gestation. Conservative management should be considered if there is no poor prognostic factor. CASE REPORT: This is a 35 year-old female with twin pregnancy with acardiac monster. Under the request of the patient, there was no intervention during the whole pregnancy. We keep regular and close sonography weekly follow up. There was no maternal complication and there was also no heart failure sign or polyhydramnios of the donor twin. Minimal blood flow was noted at the anastomotic vessels under the sonography at late gestational age. Due to breech presentation, cesarean section was performed at gestational age 37 + 1/7 weeks. She delivers a healthy baby smoothly. CONCLUSION: Antenatal sonography is an important tool to evaluate the fetus status. Under special condition, term pregnancy is still possible without any treatment. CASE REPORT: Twin reversed arterial perfusion syndrome in a monochorionic monoamniotic twin pregnancy.

Laser therapy for twin-twin transfusion syndrome in a dizygotic monochorionic twin pregnancy: A case report.

OBJECTIVE: A monochorionic dizygotic (MCDZ) twin is rare, especially when complicated with twin-twin transfusion syndrome (TTTS) and treated by laser therapy. CASE REPORT: A pregnancy achieved from oocyte donation and intracytoplasmic sperm injection resulted in two embryos transferred. A monochorionic diamniotic twin pregnancy was diagnosed by an early ultrasound; however, at 16 weeks of gestation, instead of the same sex, the ultrasound suspected there was sex discrepancy between the twins. TTTS with severe polyhydramnios occurred at 22 weeks, leading to a laser therapy, which was followed with a smooth post-operation course. Then the Cesarean section was performed at the gestational age of 29 weeks due to severe preeclampsia, giving birth to two live newborns: one female and one male baby both without neurological sequelae at the time of discharge. Blood chromosomes obtained at delivery and 65 days after delivery all revealed an XX and XY chimera from both babies. CONCLUSION: Laser therapy is also effective in MCDZ twin complicated with TTTS. Determination of chorionicity in early pregnancy could timely prompt us to watch out for complications unique to monochorionic twin pregnancy.