Role of gestational age at time of placental laser surgery in outcomes of twin-to-twin transfusion syndrome.

OBJECTIVE: There are conflicting data on whether fetoscopic laser photocoagulation of placental anastomoses (FLP) for treating twin-to-twin transfusion syndrome (TTTS) is associated with lower rates of overall survival. The objective of this study is to characterize survival and other associated morbidity after FLP across gestational ages of FLP. METHODS: This is a secondary analysis of prospectively collected data on patients with monochorionic-diamniotic twins that had FLP for TTTS at two centers between 2011 and 2022. Patients were divided into gestational age epochs for FLP before 18 wks, 18 0/7 - 19 6/7 wks, 20 0/7 - 21 6/7 wks, 22 0/7 - 23 6/7 wks, 24 0/7 - 25 6/7 wks and after 26 wks. Demographic characteristics, sonographic characteristics of TTTS and operative characteristics were compared across the gestational age epochs. Outcomes including overall survival, preterm delivery, preterm prelabor rupture of membranes (PPROM), intrauterine fetal demise (IUFD) and neonatal demise (NND) were also compared across gestational age epochs. Multivariate analysis was performed by fitting logistic regression models for these outcomes. Kaplan-Mejer curves were constructed to compare the interval from PPROM to delivery for each gestational age epoch. RESULTS: There were 768 patients that met inclusion criteria. The dual survival rate was 61.3% for FLP performed prior to 18 weeks compared to 78.0% - 86.7% across later gestational age epochs. This appears to be related to increased rates of donor IUFD following FLP performed before, versus after 18 weeks (28.0% vs. 9.3% - 14.1%). Rates of recipient IUFD/NND and donor NND were similar regardless of gestational age of FLP. Rates of PPROM were higher for earlier FLP, ranging from 45.6% for FLP before 18 weeks to 11.9% for FLP at 24 - 26 weeks gestational age. However, the gestational age of delivery was similar across gestational age epochs with a median of 31.7 weeks. In multivariate analysis, donor loss was independently associated with FLP before 18 weeks after adjusting for selective fetal growth restriction, Quintero stage and other covariates. PPROM and PTD were also associated with FLP before 18 weeks after adjusting for cervical length, placental location, trocar size, laser energy and amnioinfusion. CONCLUSION: FLP performed at earlier gestational ages is associated with lower overall survival, which is driven by higher risk of donor IUFD, as opposed to differences in PPROM or PTD. Counseling regarding survival should account for gestational age of presentation. This article is protected by copyright. All rights reserved.

Predictors of Poor Outcomes in Monochorionic Diamniotic Twin Pregnancies Complicated by Selective Fetal Growth Restriction.

INTRODUCTION: The aim of the study was to identify predictors of poor outcomes in monochorionic diamniotic twin (MCDA) pregnancies with selective fetal growth restriction (sFGR), irrespective of the umbilical artery (UA) Doppler abnormalities. METHODS: Single-center retrospective analysis of MCDA twins diagnosed with sFGR that opted for expectant management between 2010 and 2021. The presence of any of the following variables in the growth-restricted fetus: low amniotic fluid volume (DVP ≤2 cm), lack of a cycling bladder, absent or reversed flow in the ductus venosus (DV) with atrial contraction, and elevated middle cerebral artery peak systolic velocity (MCA-PSV) defined as ≥1.50 multiples of the median was categorized as complicated. sFGR cases were classified as simple in the absence of the above-mentioned variables. RESULTS: Overall, 63.3% of cases qualified as simple, and 36.7% were complicated. Intertwin EFW discordance was higher in the complicated category (26 vs. 33%, p = 0.0002). The median gestational age at delivery was earlier (33 weeks vs. 30.5 weeks, p = 0.002), and the likelihood of survival was lower in the complicated category (p < 0.0001). The likelihood of two survivors to discharge was lower in type I complicated cases (70% in complicated type I vs. 97.1% in simple type I, p = 0.0003). On logistic regression analysis, an increase in the "complicated" score negatively correlated with two survivors to discharge (p < 0.0001). An ROC curve was created, and the AUC was 0.79. Increasing intertwin EFW discordance also decreased the probability of two survivors to discharge. CONCLUSION: The presence of oligohydramnios, lack of a cycling bladder, abnormal DV Doppler, and elevated MCA-PSV in the growth restricted fetus is associated with poor perinatal outcomes and a lower likelihood of having two survivors to discharge. The addition of intertwin EFW discordance to these variables helped improve the survival predictability.

Thick artery-artery anastomoses delay the onset of selective fetal growth restriction in monochorionic diamniotic twins: a 7-year single-center cohort study.

Objective: This study aimed to investigate differences in placental characteristics between early- and late-onset selective fetal growth restriction (sFGR) in monochorionic diamniotic twins. Methods: A total of 253 patients with sFGR between April 2013 and April 2020 were retrospectively analyzed. Placental characteristics of early- and late-onset sFGR were compared. Results: The gestational age at diagnosis and delivery in the early-onset group was significantly less than that in the late-onset group [22.0 (16.9-23.9) and 28.4 (24.0, 36.3) weeks, P < 0.001; 33.1 ± 2.2 and 33.7 ± 2.5 weeks, P = 0.025]. The birth weight of normal growth and growth-restricted fetuses in the early-onset group was less than the late-onset group [1,990 ± 422 and 2,162 ± 525 g, P = 0.044; 1,320 ± 409 and 1,595 ± 519 g, P = 0.001]. The birthweight discordance ratio in the early-onset group was greater than the late-onset group (0.34 ± 0.12 and 0.29 ± 0.13, P = 0.001). The early-onset group had a significantly lower prevalence of sFGR type I than the late-onset group (37.5 and 62.0%, P = 0.018). The early-onset group had a significantly higher prevalence of sFGR type III than the late-onset group (30.4 and 12.7%, P = 0.048). The early-onset group had a lower prevalence of thick artery-artery anastomoses than the late-onset group (37.5 and 62.0%, P = 0.006). The placental territory discordance ratio in the early-onset group was higher than in the late-onset group [0.60 (0.01, 0.80) and 0.50 (0.01, 0.88), P = 0.018]. Conclusion: Unequal placental territory is the cause for most of the late-onset sFGR. Thick artery-artery anastomoses may delay the onset time of these cases of sFGR.

Prenatally diagnosed giant umbilical cord resulted from patent urachus in a monochorionic diamniotic twin with selective intrauterine growth restriction.

A long diffuse giant umbilical cord (GUC), caused by umbilical cord edema associated with a patent urachus, is an extremely rare anomaly. While patients with diffuse GUC appear to experience no significant complications and a good prognosis, little is known about their etiology and prenatal course. Here, we report the first case of prenatally diagnosed diffuse GUC resulted from patent urachus in a monochorionic diamniotic twin with selective intrauterine growth restriction. This case indicates that GUC is epigenetic and unrelated to multiple births.

Predictors of dual demise within the first week after selective cord occlusion via radiofrequency ablation for complex monochorionic pregnancies.

BACKGROUND: Selective cord occlusion is an option in complicated monochorionic multiple gestations with the goal of reducing the pregnancy by one fetus and to optimize the outcomes for the remaining fetus(es). OBJECTIVE: This study aimed to determine the rate and associated risk factors of dual demise in complex monochorionic pregnancies after selective cord occlusion via radiofrequency ablation. STUDY DESIGN: This was a single-center analysis of a prospective registry cohort of complex monochorionic pregnancies managed with selective cord occlusion via radiofrequency ablation between 2014 and 2021. A total of 167 pregnancies met the inclusion criteria and were evaluated on the basis of the intended outcome of dual demise vs singleton survival. Risk factors were compared between the 2 groups. The Mann-Whitney U test was used for continuous variables and the Fisher exact test was used for categorical variables. RESULTS: The incidence of postprocedure dual demise within the first week after performing radiofrequency ablation was 10.8% (18/167). The risk was higher in pregnancies undergoing radiofrequency ablation for discordant anomaly, and this subcategory constituted 38.9% of pregnancies in the dual demise subgroup (P=.02). Lower intertwin estimated fetal weight discordance (P=.01) was associated with dual demise. Perioperative variables including gestational age at procedure, placental cord insertion distance, operative time, and radiofrequency ablation time were similar in those with and without dual demise. CONCLUSION: Our results show that selective cord occlusion via radiofrequency ablation is a safe and reasonable option in complicated monochorionic pregnancies, with low rates of dual demise within the first week after the procedure.

Obstetric perinatal and maternal outcomes of monochorionic diamniotic twins following assisted reproductive techniques. Retrospective observational study / Resultados obstétricos perinatales y maternales en gemelos monocoriales diamnióticos conseguidos mediante técnicas de reproducción asistida. Estudio observacional retrospectivo

Introduction: Multiple and specifically monochorionic diamniotic (MCDA) pregnancies are related to maternal and foetal complications. The aim of this study is to evaluate obstetric and perinatal outcomes of MCDA after assisted reproductive techniques (ART). Methods: This is a case-control study comparing 23 MCDA twin pregnancies after ART (ART-MCDA) and 75 spontaneous MCDA (sMCDA). Maternal, obstetric, foetal, and perinatal outcomes variables including maternal age, prematurity, TTTS, sIUGR, TAPS, PROM, and neonatal weight were compared. Results: mean maternal age is higher in the ART-MCDA pregnancies, 38.0±.6 (OR=1.32(1.13–1.53)). Neonates weighing between 1500 and 2500g are more frequent in the sMCDA group and those weighing >2500g in the ART group (OR=0.47(0.22–0.97)). Foetuses born at between 32 and 37 weeks are more frequent in sMCDA pregnancies and those born >37 in the TRA group (OR=0.27(0.09–0.80)). These differences are lost when we adjust the results by maternal age. There were no differences in maternal, obstetric, or foetal complications. Conclusions: ART-MCDA are not associated with a higher number of maternal, obstetric or foetal complications if they are adjusted by maternal age. When they are not adjusted by maternal age, there would be better outcomes such as premature and neonatal weight in the ART group.(AU)

Antecedentes: El incremento de las técnicas de reproducción asistida (TRA) ha supuesto un aumento de las gestaciones gemelares en general, pero también de las monocoriales biamnióticas (MCBA), que se asocian a diversas complicaciones maternofetales. Estas complicaciones están bien estudiadas en gestaciones espontáneas, pero no en aquellas conseguidas mediante una TRA. Objetivo: Comparar la incidencia de complicaciones maternas, fetales, obstétricas y perinatales en gestaciones MCBA conseguidas de forma espontánea frente a aquellas conseguidas mediante TRA. Materiales y métodos: Estudio de casos-controles retrospectivo. Se han analizado 98 gestaciones gemelares MCBA controladas en la Unidad de Medicina Materno-Fetal del Servicio de Obstetricia del Hospital La Paz de Madrid entre los años 2015 y 2020. Resultados: La media de edad de las madres de las gestaciones MCBA conseguidas mediante TRA es mayor (OR=1,32 [1,13-1,53]). Los recién nacidos de peso entre 1.500-2.500g son más frecuentes en las gestaciones MCBA conseguidas de forma espontánea y los de >2.500g en las de TRA (OR=0,47 [0,22–0,97]). Los recién nacidos entre las 32-37 semanas son más frecuentes en las gestaciones gemelares MCBA espontáneas y los recién nacidos de >37 semanas en las de TRA (OR=0,27 [0,09-0,80]). Cuando estos resultados se ajustan por la edad materna dejan de ser estadísticamente significativos. Conclusiones: Las TRA no conllevan un aumento de las complicaciones en las gestaciones MCBA cuando se ajustan los resultados por la edad materna. Si no se ajustasen por la edad materna, las gestaciones MCBA conseguidas mediante TRA tendrían mejores resultados, con menos prematuridad y mayor peso del neonato.(AU)

Monochorionic twins with 15q26.3 duplication presenting with selective intrauterine growth restriction and discordant cardiac anomalies: A case report.

BACKGROUND: Duplication of the distal end of chromosome 15q has been previously implicated in a characteristic overgrowth syndrome. Additionally, many patients have other congenital malformations, including cardiac, renal, genital, and musculoskeletal anomalies. However, some patients may present with intrauterine growth restriction and short stature. Different breakpoints within 15q, as well as different environmental factors, may underlie these varied presentations. CASE PRESENTATION: We discuss monochorionic-diamniotic twins with a ~345 kb maternally inherited duplication in 15q26.3. The twins presented with discordant pathology-one twin with a single umbilical artery, selective intrauterine growth restriction, and multiple cardiac defects including aortic coarctation, aortic valve stenosis, and ventricular septal defect, whereas the other twin was unaffected. To our knowledge, this case represents the smallest reported duplication of distal 15q. CONCLUSION: The discordant phenotype seen in the twins is likely due to a complex interplay between genetic and environmental causes. The affected infant presented prenatally with growth restriction and a single umbilical artery rather than overgrowth, potentially due to a unique breakpoint within 15q. This, in turn, may have produced hemodynamic perturbations between the twins, leading to discordant cardiac disease. Our report thus highlights the importance of genetic and nongenetic mechanisms underlying discordant anomalies in monochorionic twins.

Mirror syndrome in monochorionic diamniotic twins presenting as maternal hyponatremia: A case report.

This is a case report of a 39-year-old patient, G5P1031, with monochorionic diamniotic twins at 30 weeks and 1 day of gestation, who developed mirror syndrome without twin-to-twin transfusion syndrome (TTTS) with a unique presentation of maternal and neonatal hyponatremia. Coinciding with severe hyponatremia were maternal symptoms of edema, nausea and vomiting, hypoalbuminemia, elevated uric acid, as well as fetal selective growth restriction, polyhydramnios, umbilical artery absent end diastolic flow and prolonged bradycardia of twin B. Given the poor status of twin B and the risks to twin A, the patient underwent emergent cesarean delivery. Hyponatremia in all three patients resolved in the following 48-72 h. Mirror syndrome is associated with significant maternal and fetal morbidity and mortality. In this case, severe hyponatremia posed additional risks. Therefore, electrolyte monitoring should be considered in both mother and neonate(s).

The heart after surviving twin-to-twin transfusion syndrome.

BACKGROUND: The persistent changes in cardiac structure and function in children who survived twin-to-twin transfusion syndrome remain a matter of concern and controversy. Current fetal echocardiographic parameters and their postnatal evolution can help improve our understanding of the subject. OBJECTIVE: To describe the echocardiographic changes of monochorionic fetuses affected by twin-to-twin transfusion syndrome, the recipient and the donor, before and after laser photocoagulation and to determine their evolution in the third trimester and during their first year of life. STUDY DESIGN: An observational study was conducted including 55 uncomplicated monochorionic diamniotic twins and 78 pairs with twin-to-twin transfusion syndrome, 44 stage I-II and 34 stage III-IV, prospectively enrolled from 2015 until 2018. Comprehensive echocardiography was performed at 4 time periods: before laser photocoagulation, at 24 to 72 hours after surgery, at 28 to 30 weeks of gestation, and at 6 to 12 months after birth. Echocardiographic parameters were transformed to z-scores or indexed for heart area, estimated fetal weight, or body mass surface. RESULTS: At diagnosis, recipients in all stages presented larger hearts (cardiothoracic ratio z-score: 2.77 [0.8] vs controls: -0.03 [0.5]; P<.001) and signs of ventricular hypertrophy (left end-diastolic ventricle wall thickness: 2.68 [0.7] vs controls -0.03 [0.7]; P<.001), along with systolic (cardiac index recipients: 317 [114] mL/min/kg vs controls: 400 [120] mL/min/kg, P<.001) and diastolic impairment (isovolumetric relaxation time z-score: 2.76 [0.6] vs controls: 0.05 [0.6]; P<.001). Donors presented smaller ventricular areas and diameters when compared with controls (left end-diastolic ventricle area z-score: -1.48 [1] vs 0.03 [0.9]; P<.001), along with decreased longitudinal motion (tricuspid annular plane systolic excursion z-score: -0.9 [1] vs controls -0.04 [1]; P<.001) and shorter ejection time z-score (-1.5 [0.7] vs controls: 0.0 [0.7]; P<.001). After surgery, an improvement in functional parameters was observed in both fetuses, whereas most morphometric changes prevailed in donors and recipients in the prenatal period. Postnatally, cardiac remodeling persisted in recipients (left relative wall thickness: 0.34 [0.02] vs controls: 0.30 [0.02]; P<.001), whereas donors mainly presented a decreased longitudinal motion in infancy (tricuspid annular plane systolic excursion z-score: -0.72 [0.7] vs controls: 0.23 [0.9]; P<.05). CONCLUSION: Cardiac remodeling is present in both fetuses at the twin-to-twin transfusion syndrome diagnosis, whereas diastolic dysfunction is only significant in the recipient. Fetal therapy improves most echocardiographic parameters, although postnatally, the echocardiographic changes persist in both fetuses.

Mode of birth in monochorionic versus dichorionic twin pregnancies: a retrospective study from a large tertiary centre in Germany.

BACKGROUND: Optimal mode of birth for twins, in particular monochorionic twins, has been the subject of much debate. This retrospective study compared maternal and newborn outcomes after vaginal birth in monochorionic and dichorionic twins, utilizing a large institutional database. METHODS: Retrospective analysis focusing on 98 monochorionic-diamniotic (MC-DA) and 540 dichorionic-diamniotic (DC-DA) twin births extracted from the perinatal database of a large German hospital. Pregnancies ≥36 weeks of gestation with two viable foetuses born between 2004 and 2014 divided into planned vaginal and planned caesarean delivery were included. Descriptive analysis was performed for maternal characteristics. Odds ratios (OR) with 95% confidences intervals (CI) tested the predictive effect of vaginal birth on neonatal and maternal outcomes. RESULTS: 51.0% MC-DA and 46.7% DC-DA twin pregnancies were planned vaginal births and 44.0% MC-DA mothers and 43.7% DC-DA mothers actually gave birth vaginally. The overall rate of caesarean section (CS) during the years under observation was 79.6% for MC-DA and 77.0% for DC-DA pregnancies. There were no significant differences in neonatal outcome between the subsamples, although acidosis was observed more often in the second DC-DA twin and Apgar scores < 7 were observed more often in MC-DA twins. CONCLUSION: Vaginal birth may be recommended as an option to women with monochorionic twins as no significant differences in outcomes were found between MC-DA and DC-DA twins. However, over half of planned vaginal twin births resulted in CS.

The Delphi definition for selective fetal growth restriction may not improve detection of pathologic growth discordance in monochorionic twins.

BACKGROUND: A consensus definition of selective fetal growth restriction in monochorionic diamniotic twins was recently proposed following a Delphi procedure involving an international panel of experts. The new definition augments the traditional definition with additional sonographic criteria. OBJECTIVE: We sought to determine whether the augmentations of the "Delphi definition" identified additional morbidity and mortality compared with a traditional definition. Furthermore, we sought to determine the benefit of each definition in identifying pathologic growth restriction relative to uncomplicated monochorionic diamniotic twins. STUDY DESIGN: This was a retrospective analysis of unselected monochorionic diamniotic twins that underwent fortnightly ultrasound surveillance at a single center between 2011 and 2020. Patients with concomitant twin-to-twin transfusion syndrome, twin anemia polycythemia sequence, or twin reversed arterial perfusion sequence at the time of diagnosis of selective fetal growth restriction were excluded. The diagnosis of selective fetal growth restriction using the Delphi definition required either an estimated fetal weight of <3rd percentile or presence of 2 of 4 observations in the smaller twin: (1) estimated fetal weight of <10th percentile, (2) estimated fetal weight discordance of >25% compared with the larger twin, (3) abdominal circumference of <10th percentile, (4) umbilical artery pulsatility index of >95th percentile. Diagnosis using the traditional definition required an estimated fetal weight of <10th percentile and an estimated fetal weight discordance of >25%. To determine the efficacy of the augmentations in the Delphi definition, 3 groups were compared: group I, uncomplicated monochorionic diamniotic twins; group II, twins with selective fetal growth restriction using the traditional definition (and therefore the Delphi definition); and group III, twins with selective fetal growth restriction solely using the Delphi definition. Demographic characteristics, subsequent development of twin-to-twin transfusion syndrome or twin anemia polycythemia sequence, pregnancy outcomes, and neonatal outcomes were compared. RESULTS: There were 325 patients with monochorionic diamniotic twins that met inclusion criteria. Of these, 213 (66%; group I) were uncomplicated, 37 (11%; group II) met the traditional definition for selective fetal growth restriction, and 112 (35%) met the Delphi definition for selective fetal growth restriction with 75 (67%) meeting solely the Delphi definition (group III). Demographic characteristics were similar between groups. Patients in group II delivered earlier than uncomplicated twins (32.1 vs 35.7 weeks of gestation; P<.01) and patients in group III (32.1 vs 35.6 weeks of gestation; P<.01). Furthermore, they were more likely to have critical umbilical artery Doppler abnormalities (38% vs 4%; P<.01) and be delivered for deteriorating fetal status (30% vs 5%; P<.01) than those in group III. Overall, survival was lower in group II than groups I and III (89% vs 96% and 100%, respectively; P=.04). Moreover, composite neonatal morbidity and mortality were greater in group II (30%) than either group I (6%; P<.01) or group III (9%; P<.01). The rates of composite neonatal morbidity and mortality were similar between groups I and III (P=.28). CONCLUSION: The addition of abdominal circumference and umbilical artery pulsatility index thresholds and isolated estimated fetal weight of <3%, as proposed by the Delphi definition, increased the diagnosis of selective fetal growth restriction; however, there was no added benefit in the identification of growth discordant pregnancies at risk of adverse outcomes. Prospective analysis of monochorionic diamniotic twins is required to contextualize these findings.

Comparison of pregnancy outcomes and placental characteristics between selective fetal growth restriction with and without thick arterio-arterial anastomosis in monochorionic diamniotic twins.

BACKGROUND: Unequal placental territory in monochorionic diamniotic twins is a primary cause of selective fetal growth restriction (sFGR), and vascular anastomoses play important role in determining sFGR prognosis. This study investigated differences in placental characteristics and pregnancy outcomes in cases of sFGR with and without thick arterio-arterial anastomosis (AAA). METHODS: A total of 253 patients diagnosed with sFGR between April 2013 and April 2020 were retrospectively analyzed. An AAA greater than 2 mm in diameter was defined as a thick AAA. We compared placental characteristics and pregnancy outcomes between cases of sFGR with and without thick AAA. RESULTS: Prevalence of AAA, thick arterio-venous anastomosis (AVA), veno-venous anastomosis (VVA), and thick VVA were significantly higher in the thick AAA group relative to the non-thick AAA group (100.0 vs. 78.5%, P < 0.001; 44.3 vs. 15.4%, P < 0.001; 27.1 vs. 10.8%, P = 0.017, and 24.3 vs. 6.2%, P = 0.004, respectively). The total numbers of AVA and total anastomoses were significantly higher in thick AAA group relative to the non-thick AAA group (5 [1, 14] vs. 3 [1, 15, P = 0.016; and 6 [1, 15] vs. 5 [1, 16], P = 0.022, respectively). The total diameter of AAA, AVA, VVA, and all anastomoses in the thick AAA group was larger than in the non-thick AAA group (3.4 [2.0,7.1] vs. 1.4 [0.0, 3.3], P < 0.001; 6.3 [0.3, 12.0] vs. 2.5 [0.3, 17.8], P < 0.001; 4.2±1.8 vs. 1.9±1.2, P =0.004; and 10.7 [3.2,22.4] vs. 4.4 [0.5, 19.3], P < 0.001, respectively). Growth-restricted fetuses in the thick AAA group exhibited significantly increased birthweight relative to those in thenon-thick AAA group (1570 (530, 2460)g vs. 1230 (610, 2480)g, p = 0.002). CONCLUSIONS: In the placentas associated with sFGR, thick AAA can co-occur with thick AVA and VVA, and placental angiogenesis may differ significantly based upon whether or not thick AAA is present. The birth weights of growth-restricted fetuses in cases of sFGR with thick AAA are larger than in cases without thick AAA.

Reference values for fetal Doppler-based cardiocirculatory indices in monochorionic-diamniotic twin pregnancy.

BACKGROUND: Placental anastomoses in monochorionic diamniotic (MCDA) twin pregnancy have a major impact on fetal circulation. This study was designed to define reference ranges of cardiac and vascular Doppler indices in MCDA twin pregnancies. METHODS: This cross-sectional study included 442 uncomplicated MCDA twin fetuses undergoing Doppler ultrasonography at 18-35 weeks of gestation. Left and right myocardial performance index (LV-MPI, RV-MPI), E/A ratio of atrioventricular valves, pulsatility indices of umbilical artery, middle cerebral artery (MCA), and ductus venosus (DV), cerebroplacental ratio, peak systolic velocity of MCA, S/a ratio of DV, and early diastolic filling time of ductus venosus (DV-E) were evaluated under standardized settings. The equation models between Doppler indices and gestational age (GA) were fitted. After adjustment for GA, the correlations between MPI and fetal heart rate (FHR), and between MPI and DV indices were analyzed. RESULTS: Estimated centiles of Doppler indices were derived as a function of GA, being distinct in values from those of singletons. There was no correlation between GA-adjusted MPI and FHR. DV-E was inversely related to LV-MPI. CONCLUSIONS: MCDA twins showed significant changes in some Doppler indices throughout gestation with quantitative differences from singletons, emphasizing the importance of MC twin-specific reference values for clinical application. Further adjustment of MPI for FHR was unnecessary. DV-E is a vascular index indirectly representing fetal diastolic function.

Long-term evolution of mucopolysaccharidosis type I in twins treated with enzyme replacement therapy plus hematopoietic stem cells transplantation.

Mucopolysaccharidoses (MPSs) are a heterogeneous group of diseases that have in common the accumulation of glycosaminoglycans (mucopolysaccharides) within the lysosome. The diseases are caused by a deficiency of the enzyme α-L-iduronidase which is responsible for the degradation of glycosaminoglycans (GAGs or mucopolysaccharides). More than 100 mutations in the gene have been reported, resulting in marked clinical/response variability. MPSs usually present as multisystem and progressive clinical disorders which affect psychomotor and cardiovascular development, the cornea and the musculoskeletal system. Seven phenotypically distinct diseases have been described, and MPS type I (MPS-I) is divided into three clinical forms: severe (Hurler syndrome), intermediate (Hurler-Scheie syndrome) or mild (Scheie syndrome). For the treatment of MPS-I, Enzyme Replacement Therapy (ERT) with α-L-iduronidase and Hematopoietic Stem Cells Transplantation (HSCT), separately or in combination, have produced clinical improvement, especially with regards cardiovascular symptoms and psychomotor development. This article presents the long-term (more than seven years) follow-up of monochorionic, diamniotic twins who were diagnosed with MPS-I at an early stage, and treated with ERT (from age 10 months) plus HSCT (from age 18 months). Overall, the treatment has facilitated stable development with an overall good response and better control of symptoms associated with MPS-I.

Risk Factors and Outcomes Following Septostomy during Fetoscopic Surgery for Twin-to-Twin Transfusion Syndrome.

Fetoscopic laser photocoagulation (FLP) of placental anastomoses is the preferred treatment for twin-to-twin transfusion syndrome (TTTS). Iatrogenic septostomy (IOS) during FLP is associated with increased risk of neonatal morbidity and mortality. We sought to identify risk factors for IOS and quantify the resultant outcomes. This is a secondary analysis of prospectively collected cases of TTTS in monochorionic diamniotic twins following FLP at a single center. Pre-operative ultrasound characteristics and operative technique (i.e., cannula size, total energy used) were compared between cases with vs. without IOS. Pregnancy and neonatal outcomes were also compared. Of 475 patients that had FLP, 33 (7%) were complicated by IOS. There was no association between operative technique and IOS. IOS was more common with later diagnosis, but less likely when selective fetal growth restriction (sFGR) was present. Survival was similar between groups (76% vs. 76% dual survivors, p = 0.95); however, IOS was associated with earlier delivery (29.7 vs. 32.0 wks, p < 0.01) and greater composite neonatal morbidity (25% vs. 8% in both twins, p = 0.02). Risks of IOS at greater gestational ages without sFGR may be related to a larger collapsed intervening membrane area and the resulting increased risk of puncture on entry.

Risk Factors Associated with Preterm Prelabor Rupture of Membranes after Cord Occlusion in Monochorionic Diamniotic Twins.

INTRODUCTION: Preterm prelabor rupture of membranes (PPROM) is a common complication after fetal surgeries. The aim of this study was to assess risk factors for and outcomes after PPROM following cord occlusion (CO) in monochorionic diamniotic (MCDA) pregnancies. METHODS: This was a retrospective cohort study of 188 consecutive MCDA pregnancies treated by bipolar or laser CO, either primarily because of discordant malformation (dMF) or severe selective fetal growth restriction (sFGR), or secondarily when complete bichorionization was not possible in case of twin-to-twin transfusion syndrome (TTTS) or sFGR. Intentional septostomy was performed when needed. The procedure-related PPROM was defined as rupture of membranes <32 weeks' gestation (PROM <32 weeks). Selected pre-, intra-, and early postoperative variables were analyzed by univariate and binomial logistic regression to determine they are correlated to PROM <32 weeks after CO. RESULTS: Between 2006 and 2017, 188 cases underwent CO. Diagnosis was TTTS in 28.2% (n = 53), severe sFGR in 49.5% (n = 93), and dMF in 22.3% (n = 42). PROM <32 weeks occurred in 21.3% (n = 40), resulting in worse perinatal outcomes, as preterm birth <32 weeks occurred in 80.7% (vs. 8.3%, p = 0.000), procedure-to-delivery interval was 47.5 days (vs. 125, p = 0.000), gestational age (GA) at birth 30.0 weeks (vs. 37.7 weeks, p = 0.000), and survival 65.0% (vs. 91.1%, p = 0.000). In univariate analysis, indication, anterior placenta, cervical length, GA at surgery, operation time, amniodistention and drainage fluid volumes, chorioamniotic membrane separation, and septostomy were selected as relevant factors to be included in the regression model. In a multivariate analysis, TTTS was the only factor associated to PROM <32 weeks (OR 3.5 CI 95% 1.5-7.9). CONCLUSIONS: PROM <32 weeks after CO increases the risk of preterm delivery. In this cohort, the membrane rupture was more likely when CO was done in the context of TTTS.

Prenatal diagnosis of fetal right ventricular diverticulum with massive pericardial effusion in one of monochorionic diamniotic twins: a case report with a favorable outcome following in utero pericardiocentesis.

BACKGROUND: Congenital ventricular diverticulum is a rare abnormality that may occur as an isolated malformation. Most cases are accompanied by pericardial effusion. Prenatal counseling can be difficult because the prognosis is uncertain and there is no consensus approach to prenatal management.Case presentation: We describe a case of congenital cardiac diverticulum complicated by large pericardial effusion in one of monochorionic diamniotic twins. The case was diagnosed by ultrasonography at 21 weeks of gestation. Therapeutic pericardiocentesis at 22 weeks resulted in complete resolution of the effusion and led to a favorable fetal outcome. We summarize the interventions and pregnancy outcomes in cases of cardiac diverticula reported in the literature. CONCLUSIONS: Better awareness of clinical features, in utero therapies, and pregnancy outcomes could help define and improve prenatal management of congenital ventricular diverticula.

Perinatal outcome of monochorionic diamniotic twin pregnancy complicated by selective intrauterine growth restriction according to umbilical artery Doppler flow pattern: single-center study using strict fetal surveillance protocol.

OBJECTIVE: To determine the perinatal outcome of monochorionic diamniotic (MCDA) twin pregnancies complicated by selective intrauterine growth restriction (sIUGR), which were classified according to the umbilical artery (UA) Doppler flow pattern of the IUGR twin. METHODS: This was a retrospective cohort study of all MCDA twin pregnancies diagnosed with sIUGR and managed at a single tertiary referral center between 2012 and 2018. Cases were classified according to the UA Doppler flow pattern of the IUGR twin as Type I (positive end-diastolic flow), Type II (persistently absent/reversed end-diastolic flow) or Type III (intermittently absent/reversed end-diastolic flow). Patients with Type-II or -III sIUGR were hospitalized at 26-28 weeks of gestation for increased fetal surveillance. Perinatal and immediate and long-term neurodevelopmental outcomes were stratified according to the UA Doppler flow pattern at the final examination. Intact survival rate was defined as the number of infants surviving without neurological impairment, divided by the total number of fetuses. Composite adverse outcome, defined as any mortality, presence of severe brain lesions on postnatal transcranial ultrasound or severe neurological morbidity, was also assessed. RESULTS: Of 88 MCDA twin pregnancies with sIUGR included in the study, 28 underwent selective termination by cord occlusion using radiofrequency ablation, resulting in a perinatal survival rate of 89.3% and a median gestational age (GA) at delivery of 33.8 (interquartile range (IQR), 28.8-38.2) weeks for the large cotwin. Expectant management was employed in 60 cases. In 26 (43.3%) cases in the expectant-management group, the classification according to the UA Doppler flow pattern changed during gestation, resulting in 26 (43.3%) cases of Type-I, 22 (36.7%) cases of Type-II and 12 (20.0%) cases of Type-III sIUGR at the final examination. The perinatal survival rate of both twins with sIUGR Types I, II and III at the final examination was 100%, 81.8% and 75.0%, respectively (P = 0.04). Two cases of double fetal death and one case of single fetal death occurred 1-4 weeks after the Doppler pattern had changed from Type I or Type II to Type III. The median GA at delivery was 34.8 (IQR, 33.1-35.7) weeks in Type I, 30.3 (IQR, 28.6-32.1) weeks in Type II and 32.0 (IQR, 31.3-32.6) weeks in Type III (P < 0.01). The total intact survival rate was 100% for Type I, 77.3% for Type II and 75.0% for Type III (P < 0.001). Multivariate analysis demonstrated that early GA at diagnosis (odds ratio (OR), 0.83 (95% CI, 0.69-0.99); P = 0.04) and the presence of Type II or III vs Type I at the last examination (OR, 13.16 (95% CI, 1.53-113.32); P = 0.02) were associated with preterm birth < 32 weeks' gestation. Early GA at diagnosis was also associated with the composite adverse outcome (OR, 0.60 (95% CI, 0.36-0.99); P = 0.04). CONCLUSIONS: The classification system of MCDA pregnancy complicated by sIUGR, according to the UA Doppler flow pattern of the IUGR twin at final examination, is associated with perinatal outcome. Importantly, the UA Doppler flow pattern can change during gestation, which has an impact on the risk of fetal death. Nevertheless, under strict fetal surveillance, the perinatal outcome of these pregnancies is favorable. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Renal artery Doppler studies in the assessment of monochorionic, diamniotic twin pregnancies with and without twin-twin transfusion syndrome.

BACKGROUND: In monochorionic, diamniotic twin pregnancies complicated by twin-twin transfusion syndrome, imbalanced fetofetal blood shunting and discordant activation of the renin-angiotensin system result in a hypovolemic, oliguric donor twin and a hypervolemic, polyuric recipient twin. Renal artery Doppler assessments have been reported to predict oligohydramnios in singleton pregnancies; however, their value in assessing monochorionic, diamniotic twin gestations, including pregnancies complicated by twin-twin transfusion syndrome, remains unstudied. OBJECTIVE: This investigation evaluated whether renal artery Doppler parameters are different between sets of monochorionic, diamniotic twins with and without twin-twin transfusion syndrome. STUDY DESIGN: We conducted a prospective study of women with monochorionic, diamniotic twin pregnancies complicated by twin-twin transfusion syndrome and women with gestational-age matched monochorionic, diamniotic twin control pregnancies without twin-twin transfusion syndrome. For each twin, renal artery Doppler assessment was performed from a coronal view of the fetus, and pulsatility index, resistive index, and peak systolic velocity were measured. In twin pairs complicated by twin-twin transfusion syndrome, renal artery Doppler pulsatility index, resistive index, and peak systolic velocity intertwin ratios were calculated by comparing paired recipient-to-donor values. Similar ratios were calculated for control twin pairs. We compared each measurement between donors and controls and between recipients and controls. Intertwin ratios were compared between twin-twin transfusion syndrome cases and monochorionic, diamniotic controls. Our primary outcome was a comparison of renal artery Doppler pulsatility index measurement between donor fetuses in twin-twin transfusion syndrome cases and matched control twins. Secondary outcomes included comparisons of other renal artery Doppler parameters between twin-twin transfusion syndrome donor twins and controls and between twin-twin transfusion syndrome recipients and controls and comparisons of the renal artery Doppler parameter ratios between twin-twin transfusion syndrome and non-twin-twin transfusion syndrome twin pair groups. Finally, we performed a subgroup analysis involving pregnancies with twin-twin transfusion syndrome that underwent fetoscopic laser therapy and resulted in twin survivors to evaluate if laser therapy influenced renal artery Doppler findings. RESULTS: We recruited 12 donors and 12 controls. Renal artery Doppler pulsatility index and resistive index did not differ between donors and controls. However, donor renal artery Doppler peak systolic velocity (median, 14.24 [11.51-15.36]) was significantly lower than that of controls (median, 24.79 [22.46-27.03]; P<.0004). When recipient twins were compared with controls, there was no difference in renal artery Doppler pulsatility index, renal artery Doppler resistive index, or renal artery Doppler peak systolic velocity. Renal artery Doppler peak systolic velocity ratios were significantly higher among cases with twin-twin transfusion syndrome (median, 1.70 [1.53-2.02]) than controls (median, 1.06 [1.03-1.15]; P=.002). Applying a renal artery Doppler peak systolic velocity ratio cutoff of >1.35 for the diagnosis of twin-twin transfusion syndrome correctly classified 11 of 12 cases with twin-twin transfusion syndrome and all 12 controls without twin-twin transfusion syndrome (92% sensitivity and 100% specificity). Among donors with twin-twin transfusion syndrome with double survivors after undergoing laser therapy (n=4), prelaser renal artery Doppler peak systolic velocity ratios (mean, 1.46; standard deviation, 0.37) were significantly higher than postlaser renal artery Doppler peak systolic velocity ratios (mean, 0.87; standard deviation=0.37; P=.02). Postlaser intertwin renal artery Doppler peak systolic velocity ratios did not differ from control twin pairs (P=.125). CONCLUSION: Renal artery Doppler peak systolic velocity ratios differ between monochorionic, diamniotic twins with twin-twin transfusion syndrome and those without twin-twin transfusion syndrome. This effect seems to be driven by altered donor twin renal artery Doppler peak systolic velocity. Laser therapy may normalize renal artery Doppler peak systolic velocity ratios and donor twin renal artery Doppler values to those observed in monochorionic, diamniotic twins without twin-twin transfusion syndrome. Further study is warranted to explore whether renal artery Doppler peak systolic velocity has utility as a tool for twin-twin transfusion syndrome prediction, diagnosis, or staging, and fetal response to laser therapy.

A case report of fetus in fetu with an aorta-like structure visualized by contrast-enhanced CT.

Fetus in fetu (FIF) is a rare congenital anomaly resulting from abnormal embyogenesis in monochorionic diamniotic twins and appears as a cystic mass containing fetus-like structures mainly in the retroperitoneum of infants. Although there is a theory that FIF is a highly differentiated teratoma, it is commonly distinguished from teratoma as a mass containing a vertebral axis with appropriate arrangement of limbs or other organs around this axis. Here we present a case of FIF with aorta-like structure visualized by contrast-enhanced computed tomography. A 5-day-old girl was pointed out a cystic mass in the abdomen by ultrasound examination. Abdominal contrast-enhanced computed tomography revealed a retroperitoneal cystic mass with spine- and limb-like bone structures and blood vessel-like elongated structures and it was confirmed as FIF by surgery. The presence of major vascular structures along the skeletal axis is clearly different from teratoma and suggests that it occurred as an embryo and underwent some stage of development. Our findings strongly support the monozygotic twin theory.