Monochorionic twins with selective intrauterine growth restriction and intermittent absent or reversed end-diastolic flow (Type III): feasibility and perinatal outcome of fetoscopic placental laser coagulation

Diagnosis and management of selective fetal growth restriction in monochorionic twin pregnancies: A cross-sectional international survey

OBJECTIVE

To identify current practices in the management of selective fetal growth restriction (sFGR) in monochorionic diamniotic (MCDA) twin pregnancies.

DESIGN

Cross-sectional survey.

SETTING

International.

POPULATION

Clinicians involved in the management of MCDA twin pregnancies with sFGR.

METHODS

A structured, self-administered survey.

MAIN OUTCOME MEASURES

Clinical practices and attitudes to diagnostic criteria and management strategies.

RESULTS

Overall, 62.8% (113/180) of clinicians completed the survey; of which, 66.4% (75/113) of the respondents reported that they would use an estimated fetal weight (EFW) of <10th centile for the smaller twin and an inter-twin EFW discordance of >25% for the diagnosis of sFGR. For early-onset type I sFGR, 79.8% (75/94) of respondents expressed that expectant management would be their routine practice. On the other hand, for early-onset type II and type III sFGR, 19.3% (17/88) and 35.7% (30/84) of respondents would manage these pregnancies expectantly, whereas 71.6% (63/88) and 57.1% (48/84) would refer these pregnancies to a fetal intervention centre or would offer fetal intervention for type II and type III cases, respectively. Moreover, 39.0% (16/41) of the respondents would consider fetoscopic laser surgery (FLS) for early-onset type I sFGR, whereas 41.5% (17/41) would offer either FLS or selective feticide, and 12.2% (5/41) would exclusively offer selective feticide. For early-onset type II and type III sFGR cases, 25.9% (21/81) and 31.4% (22/70) would exclusively offer FLS, respectively, whereas 33.3% (27/81) and 32.9% (23/70) would exclusively offer selective feticide.

CONCLUSIONS

There is significant variation in clinician practices and attitudes towards the management of early-onset sFGR in MCDA twin pregnancies, especially for type II and type III cases, highlighting the need for high-level evidence to guide management.

Clinical Outcome of Monochorionic Diamniotic Twins with Intrauterine Growth Restriction

OBJECTIVE

This study investigated the clinical outcome of monochorionic diamniotic (MCDA) twins with selective intrauterine growth restriction (sIUGR).

STUDY DESIGN

International Peace Maternal and Child Health Hospital of Shanghai ultrasound database was investigated to identify all MCDA delivered from January 2013 to December 2017. After identifying 43 pairs of MCDA twins with sIUGR and 282 pairs of normal MCDA twins, we compared clinical outcomes between the two groups.

RESULTS

Compared with normal twins, sIUGR fetuses had significantly shorter gestational age at delivery, smaller average birth weight of both twins, more significant intertwin difference in birth weight, lower Apgar scores, and higher intrauterine fetal demise (IUFD) rate, and smaller placental weight. The rate of abnormal umbilical cord insertions and abnormal blood flow in the ductus venosus (DV) and middle cerebral artery (MCA) is significantly higher in the sIUGR group. In addition, the subtype analysis of sIUGR groups indicated the poorest outcomes in type II with no significant difference between type I and III.

CONCLUSION

MCDA twins with sIUGR generally exhibited limited clinical outcomes than normal MCDA twins. These limitations are mainly associated with abnormal umbilical cord insertions and blood flow in the DV and MCA. Clinical outcomes differed among the three types of sIUGR, with type II having the worst prognosis and the highest IUFD rate.

KEY POINTS

· sIUGR generally exhibited limited clinical outcomes than normal MCDA twins.. · These limitations are mainly associated with blood flow of the DV and MCA.. · sIUGR with type II has the worst prognosis and the highest IUFD rate..

Infant outcome at 3 years of age of monochorionic twins with Type-II or -III selective fetal growth restriction and isolated oligohydramnios that underwent fetoscopic laser photocoagulation

OBJECTIVE

To examine infant outcomes at 3 years of age in monochorionic twin pregnancies with Type-II or -III selective fetal growth restriction (sFGR) and isolated oligohydramnios who underwent fetoscopic laser photocoagulation (FLP).

METHODS

This multicenter prospective cohort study included monochorionic diamniotic twins that underwent FLP for sFGR between 16 and 25 weeks' gestation. The indication for performing FLP was Type-II or -III sFGR with oligohydramnios of the growth-restricted (FGR) twin in which the maximum vertical pocket of amniotic fluid was ≤ 2 cm. This was done in the absence of a typical diagnosis of twin-twin transfusion syndrome. The primary outcome was intact survival rate of both infants at the corrected gestational age of 40 weeks and at 3 years of age. Intact survival at the corrected age of 40 weeks was defined as survival without Grade-III or -IV intraventricular hemorrhage or cystic periventricular leukomalacia. Intact survival at 3 years of age was defined as survival without neurodevelopmental morbidity, which included cerebral palsy, neurodevelopmental impairment with a total developmental quotient of < 70, bilateral deafness or bilateral blindness.

RESULTS

Among 45 patients with sFGR, 30 (66.7%) were classified as having Type-II and 15 (33.3%) as Type-III sFGR. The prevalence of intact survival at the corrected age of 40 weeks was 51.1% (n = 23) in FGR twins and 95.5% (n = 42) in larger twins. The prevalence of intact survival at 3 years of age was 46.7% (n = 21) in FGR twins and 86.4% (n = 38) in larger twins. There was one case of miscarriage. Among the 24 FGR twins who were not classified as having intact survival at 3 years of age, 22 (91.7%) cases suffered fetal or infant demise (other than miscarriage), and there was one case of neurodevelopmental impairment. All larger twins who were not diagnosed with intact survival at 3 years of age (n = 6 (13.6%)) had neurological morbidity.

CONCLUSIONS

FGR twins and their larger cotwins, when subjected to FLP owing to sFGR coupled with umbilical artery Doppler abnormalities and isolated oligohydramnios, exhibit low rates of neurological morbidity and low mortality, respectively. Therefore, FLP for Type-II or -III sFGR with oligohydramnios may be a feasible management option and one that is preferable to expectant management. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Predictors of fetal death, neonatal survival and neurological outcomes in severe twin-twin transfusion syndrome treated by laser ablation of placental vessels

OBJECTIVES

To identify predictors of outcomes in severe twin oligo-polyhydramnios sequence (TOPS) with or without twin anemia-polycythemia sequence (TAPS) and/or selective fetal growth restriction (SFGR) treated by laser ablation of placental vessels (LAPV).

METHODS

Analysis of cases treated from 2011 to 2022. Variables evaluated Prenatal predictors: stages of TOPS, presence of TAPS and/or SFGR; pre-LAPV fetal ultrasound parameters; peri-LAPV variables. Perinatal predictors: GA at birth; birthweight; Apgar scores; transfontanellar ultrasonography (TFUS).

OUTCOME VARIABLES

fetal death, neonatal survival, infant's neurodevelopment. Binary logistic regression analyses were performed to detect predictors of outcomes.

RESULTS

265 cases were included. Predictors of post-LAPV donor fetus' death were delta EFW (p:0.045) and absent/reverse end-diastolic flow in the umbilical artery (AREDF-UA) (p < 0.001). The predictor of post-LAPV recipient fetus' death was hydrops (p:0.009). Predictors of neonatal survival were GA at birth and Apgar scores. Predictors of infant's neurodevelopment were TFUS and pre-LAPV middle cerebral artery Doppler (MCAD) for the donor twin; and pre-LAPV ductus venosus' flow and MCAD for the recipient twin.

CONCLUSIONS

Prediction of fetal death, neonatal survival and infant's neurodevelopment is possible in cases of TOPS associated or not with SFGR and/or TAPS that were treated by LAPV.

Outcome of monochorionic diamniotic twin pregnancy with selective intrauterine growth restriction, a single center study in China

INTRODUCTION

This retrospective study aimed to evaluate clinical outcomes of monochorionic diamniotic (MCDA) twins with selective intrauterine growth restriction (sIUGR).

MATERIALS AND METHODS

MCDA twins, either sIUGR and non-sIUGR, underwent expectant management from 2016 to 2019 in our hospital were included. sIUGR fetuses were classified into three types according to umbilical artery Doppler assessment. Non-sIUGR were considered as the control group. Outcomes were pregnancy outcomes and maternal complications.

RESULTS

Forty-three sIUGR (type I: 23; type II: 14, and type III: 6) and 282 non-sIUGR fetuses were included. The sIUGR group had a significantly earlier birth, lower birth weight of the twins, larger inter-twin weight difference, lower Apgar score of the twins, and higher intrauterine fetal death (IUFD) than the non-sIUGR group (all p < 0.001). The same trend was found in the sIUGR type II group compared to type I and III groups. A significantly lower gestational diabetes rate (p = 0.01) and placenta weight (p < 0.001), and higher proportions of abnormal placental umbilical cord insertion (p < 0.001), and ultrasound Doppler monitoring indicators (p = 0.006) were found in the sIUGR group than the non-sIUGR group.

CONCLUSIONS

The MCDA twins with sIUGR showed poorer outcomes than the non-sIUGR group. Doppler interrogation was a useful clinical marker for fetal outcome.

Neurological morbidity in monochorionic twins with selective fetal growth restriction

The increased risks of various obstetric, maternal and fetal comorbidities of monochorionic twin pregnancies are widely known. However, despite its high prevalence and significance, the assessment of neurological morbidity as more commonly in selective fetal growth restriction (sFGR) is concerned with more health care. This literature review aims to provide more information about such an assessment. To this end, retrospective cases of sFGR were studied in monochorionic twins, already diagnosed, classified and who had the recommended management, published between 2001 and 2018 in 17 scientific articles. In the assessment of fetal mortality, the highest risk of death of the restricted fetus was found in type 3 of sFGR, while type 2 sFGR was responsible for the highest death rates of both fetuses and also the lowest mean gestational age at delivery, 30.9 weeks. Regarding neurological morbidity, however, studies have shown a higher risk of brain damage in the habitually growing twin compared to the restricted one in the case of sFGR. This may be due to prematurity or intermittent diastolic flow on Doppler in type 2 and 3 of sFGR, however, statements about its pathophysiology still lack further studies.

Monochorionic Twins: TTTS, TAPS, and Selective Fetal Growth Restriction

With an increasing incidence of twin gestations, understanding the inherent risks associated with these pregnancies is essential in modern obstetrics. The unique differences in placentation in monochorionic twins leads to unique complications, including twin-to-twin transfusion syndrome, the twin anemia-polycythemia sequence, and selective fetal growth restriction. Not only does the understanding of the monochorionic placenta lead to an understanding of the pathophysiology of the complications of monochorionic twins, but it also has led to the development of highly effective directed fetal therapy via fetoscopic laser coagulation used in twin-to-twin transfusion syndrome.

Selective intrauterine growth restriction without concomitant twin-to-twin transfusion syndrome, natural history, and risk factors for fetal death: A systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the natural history of selective intrauterine growth restriction in monochorionic twin pregnancies based on the Gratacós classification, including progression of, improvement in, or stability of umbilical artery Dopplers and progression to twin-to-twin transfusion syndrome or twin anemia polycythemia syndrome. We also aimed to investigate risk factors for smaller twin demise.

DATA SOURCES

A systematic search was performed to identify relevant studies published in English up to June 2022 using the databases PubMed, Scopus, and Web of Science STUDY ELIGIBILITY: We used retrospective and prospective studies published in English that reported on selective intrauterine growth restriction without concomitant twin-to-twin transfusion syndrome.

STUDY APPRAISAL AND SYNTHESIS METHODS

Articles that investigated selective intrauterine growth restriction progression and outcomes by umbilical artery Doppler end-diastolic flow (Gratacós classification) were included. Type I included selective intrauterine growth restriction cases with positive end-diastolic flow, type II included those cases with persistently absent end-diastolic flow, and type III included cases with intermittent absent or reversed end-diastolic flow. Pregnancies in which a diagnosis of twin-to-twin transfusion syndrome or twin anemia polycythemia sequence was made before the diagnosis of selective intrauterine growth restriction were not included in the analysis. A random effects model was used to pool the odds ratios and the corresponding 95% confidence intervals. Heterogeneity was assessed using the I2 value.

RESULTS

A total of 17 studies encompassing 2748 monochorionic pregnancies complicated by selective intrauterine growth restriction were included in the analysis. The incidence of stable, deteriorating, or improving umbilical artery Dopplers in type I cases was 68% (95% confidence interval, 26-89), 23% (95% confidence interval, 7-40), and 9% (95% confidence interval, 0.0-100), respectively. In type II cases, the incidence was 40% (95% confidence interval, 18-81), 50% (95% confidence interval, 23-82), and 10% (95% confidence interval, 4-37), respectively, and in type III cases, the incidence was 55% (95% confidence interval, 2-99), 23% (95% confidence interval, 9-43), and 22% (95% confidence interval, 6-54), respectively. The risk for progression to twin-to-twin transfusion syndrome was comparable between type I (7%) and type III (9%) cases and occurred in 4% (95% confidence interval, 0-67) of type II cases with no significant subgroup differences. Progression to twin anemia polycythemia syndrome was highest in type I cases (12%) and comparable between type II (2%) and III (1%) cases with no significant subgroup differences. Risk factors for smaller twin demise were earlier gestational age at diagnosis (mean difference, -2.69 weeks; 95% confidence interval, -4.94 to -0.45; I2, 45%), larger intertwin weight discordance (mean difference, 34%; 95% confidence interval, 1.35-5.38; I2, 28%), deterioration of umbilical artery Dopplers for each of type II and III cases (odds ratio, 3.05; 95% confidence interval, 1.36-6.84; I2, 24%; and odds ratio, 4.5; 95% confidence interval, 2.31-8.77; I2, 0.0%, respectively), and absent or reversed ductus venosus a-wave for each of type II and III cases (odds ratio, 3.35; 95% confidence interval, 2.28-4.93; I2, 0.0%; and odds ratio, 2.36; 95% confidence interval, 1.08-5.13; I2, 0.0%, respectively). Progression to twin-to-twin transfusion syndrome was not significantly associated with smaller twin demise for each of type II and III selective intrauterine growth restriction cases.

CONCLUSION

These findings improve our understanding of the natural history of the types of selective intrauterine growth restriction and of the predictors of smaller twin demise in type II and III selective intrauterine growth restriction cases. The current data provide vital counseling points and support the need for modifications of the current selective intrauterine growth restriction classification system to include the variations in umbilical artery and ductus venosus Dopplers to better identify a cohort that might benefit from fetal intervention for which future multicenter prospective randomized trials are needed.

Directive clinique no 440 : Prise en charge de la grossesse gémellaire monochoriale

OBJECTIF

Cette directive clinique passe en revue les données probantes sur la prise en charge de la grossesse gémellaire monochoriale normale et compliquée.

POPULATION CIBLE

Les femmes menant une grossesse gémellaire ou multiple de haut rang. BéNéFICES, RISQUES ET COûTS: L'application des recommandations de cette directive devrait améliorer la prise en charge des grossesses gémellaires (ou multiples de haut rang) monochoriales compliquées et non compliquées. Ces recommandations aideront les fournisseurs de soins à surveiller adéquatement les grossesses gémellaires monochoriales ainsi qu'à détecter et prendre en charge rapidement les complications associées de façon optimale afin de réduire les risques de morbidité et mortalité périnatales. Ces recommandations impliquent une surveillance échographique plus fréquente en cas de grossesse monochoriale qu'en cas de grossesse bichoriale. DONNéES PROBANTES: La littérature publiée a été colligée par des recherches dans les bases de données PubMed et Cochrane Library au moyen de termes MeSH pertinents (Twins, Monozygotic; Ultrasonography, Prenatal; Placenta; Fetofetal Transfusion; Fetal Death; Fetal Growth Retardation). Les résultats ont été restreints aux revues systématiques, aux essais cliniques randomisés et aux études observationnelles. Aucune date limite n'a été appliquée, mais les résultats ont été limités aux contenus en anglais ou en français. MéTHODES DE VALIDATION: Les auteurs principaux ont rédigé le contenu et les recommandations et ils se sont entendus sur ces derniers. Le conseil d'administration de la SOGC a approuvé la version définitive aux fins de publication. Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations Assessment, Development and Evaluation). Voir l'annexe A en ligne (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et conditionnelles [faibles]). PROFESSIONNELS CONCERNéS: Spécialistes en médecine fœto-maternelle, obstétriciens, radiologues, échographistes, médecins de famille, infirmières, sages-femmes, résidents et autres fournisseurs de soins de santé qui s'occupent de femmes menant une grossesse gémellaire ou multiple de haut rang. RéSUMé POUR TWITTER: Directive canadienne (SOGC) pour le diagnostic, la surveillance échographique et la prise en charge des complications de la grossesse gémellaire monochoriale (p. ex., STT, TAPS, retard de croissance sélectif, cojumeau acardiaque, monoamnionicité et mort d'un jumeau). DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Guideline No. 440: Management of Monochorionic Twin Pregnancies

OBJECTIVE

This guideline reviews the evidence-based management of normal and complicated monochorionic twin pregnancies.

TARGET POPULATION

Women with monochorionic twin or higher order multiple pregnancies.

BENEFITS, HARMS, AND COSTS

Implementation of these recommendations should improve the management of both complicated and uncomplicated monochorionic (and higher order multiple) twin pregnancies. They will help users monitor monochorionic twin pregnancies appropriately and identify and manage monochorionic twin complications optimally in a timely manner, thereby reducing perinatal morbidity and mortality. These recommendations entail more frequent ultrasound monitoring of monochorionic twins compared to dichorionic twins.

EVIDENCE

Published literature was retrieved through searches of PubMed and the Cochrane Library using appropriate MeSH headings (Twins, Monozygotic; Ultrasonography, Prenatal; Placenta; Fetofetal Transfusion; Fetal Death; Fetal Growth Retardation). Results were restricted to systematic reviews, randomized controlled clinical trials, and observational studies. There were no date limits, but results were limited to English or French language materials.

VALIDATION METHODS

The content and recommendations were drafted and agreed upon by the principal authors. The Board of the SOGC approved the final draft for publication. The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations).

INTENDED AUDIENCE

Maternal-fetal medicine specialists, obstetricians, radiologists, sonographers, family physicians, nurses, midwives, residents, and other health care providers who care for women with monochorionic twin or higher order multiple pregnancies.

TWEETABLE ABSTRACT

Canadian (SOGC) guidelines for the diagnosis, ultrasound surveillance and management of monochorionic twin pregnancy complications, including TTTS, TAPS, sFGR (sIUGR), acardiac (TRAP), monoamniotic twins and intrauterine death of one MC twin.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Laser therapy versus expectant management for selective fetal growth restriction in monochorionic twins: A systematic review

Selective fetal growth restriction (sFGR) complicates 10%-26% of monochorionic twins. Treatment options include cord coagulation, expectant management, and fetoscopic laser photocoagulation. This review compared laser to expectant management for situations when cord coagulation is not an option. The MEDLINE, EMBASE, and Cochrane databases were queried for studies that compared laser to expectant management for sFGR. GRADE was used to assess quality prior to meta-analysis. A random-effects model was used to generate relative risks. Six studies were included, encompassing 299 pregnancies. One study was randomized and the remainder were retrospective cohorts. Laser is associated with more fetal deaths of the FGR twin compared to expectant management (risk ratio [RR] 2.5, 95% confidence interval [CI] 1.43-4.37, p = 0.001, I2 = 48%). Neonatal deaths and gestational age at delivery did not differ. Laser was associated with decreased abnormal neuroimaging in the AGA twin (RR 0.25, 95% CI 0.07-0.97, p = 0.05). Neurodevelopmental outcomes did not differ, although these data are limited. Laser causes more fetal deaths of the FGR twin without altering gestational age at delivery or rates of neonatal death. The literature is heterogeneous and the level of bias is high. Randomized trials that address laser for type II sFGR are needed and should include long-term neurological outcomes.

The High-Risk Profile of Selective Growth Restriction in Monochorionic Twin Pregnancies

The present review aims to provide a critical appraisal of the sonographic diagnosis and follow-up and to evaluate the optimal clinical management of monochorionic twin pregnancies where one of the twins is complicated by selective fetal growth restriction (sFGR). The classification is based on the umbilical artery (UA) diastolic flow reflecting the outcome. If the sFGR twin has positive diastolic flow (Type I) then the prognosis is good, and it does not require close surveillance. Biweekly or weekly sonographic and Doppler surveillance and fetal monitoring are recommended strategies to detect unpredictable complications in type II and type III forms, which are defined by persistently absent/reverse end-diastolic flow (AREDF) or cyclically intermittent absent/reverse end-diastolic flow (iAREDF) in the umbilical waveforms, respectively. The latest forms are associated with an increased risk of unexpected fetal demise of the smaller twin and 10-20% risk of neurological injury in the larger twin in addition to the overall risk of prematurity. The clinical course can be affected by elective fetal therapy ('dichorinization' of the placenta with laser or selective fetal reduction) or elective delivery in the presence of severe fetal deterioration. The prediction of the clinical outcome in complicated cases of type II and III sFGR cases remains elusive. Novel routines in fetal and placental scans in order to predict neurological impairments and unexpected fetal death to optimize the delivery time-point are needed.

Natural evolution and risk factors for adverse outcome in selective intrauterine growth restriction under expectant management: A retrospective observational study

OBJECTIVE

To evaluate the natural evolution of and risk factors for the adverse outcome of monochorionic twins with selective intrauterine growth restriction (sIUGR) under expectant management.

METHODS

Retrospective study conducted in a single tertiary referral center. The clinical characteristics and neonatal outcomes of 153 patients with sIUGR under expectant management were evaluated, and the risk factors leading to adverse outcomes were explored.

RESULTS

Fifty-one patients (33.3%) showed a changed pattern in umbilical artery Doppler at the last examination, occurring in all types of sIUGR. Compared with type Ia, the gestational age of diagnosis was earlier, the estimated fetal body weight difference at diagnosis was greater, and the rate of severe neonatal complications in both fetuses was significantly higher in type Ib (P < 0.05). Univariate and multivariate logistic regression analyses showed that type II (odds ratio [OR] 5.41, 95% confidence interval [CI] 2.34-12.51; P < 0.001) and type III (OR 9.11, 95% CI 3.02-27.50; P < 0.001) were associated with adverse perinatal outcomes in sIUGR.

CONCLUSION

Type II and III sIUGR are independent risk factors predicting adverse outcomes of sIUGR. Different types of sIUGR could convert to each other. The outcome of type Ib is poorer than that of type Ia.

Impact of placental sharing and large bidirectional anastomoses on birthweight discordance in monochorionic twins: a retrospective cohort study in 449 cases

BACKGROUND

In monochorionic twin pregnancies, the fetuses share a single placenta. When this placenta is unequally shared, a discordant antenatal growth pattern ensues resulting in high rates of perinatal morbidity and mortality. Understanding placental pathophysiology is paramount in devising feasible antenatal management strategies. Unequal placental sharing is not the sole determinant of birthweight discordance as there is no one-to-one relationship with placental share discordance. Placental angioarchitecture, especially the presence of large bidirectional anastomoses, is thought to affect this relationship by allowing for a compensatory intertwin blood flow.

OBJECTIVE

This study aimed to assess whether placental angioarchitecture can affect birthweight discordance in live-born monochorionic twins, the aim of our study was 2-fold: (1) to assess the relationship between birthweight discordance and placental share discordance and (2) to examine to what extent large bidirectional anastomoses can compensate for the effect of unequal placental sharing on birthweight discordance, with a subgroup analysis for umbilical artery Doppler flow patterns in cases with a birthweight discordance of ≥20%.

STUDY DESIGN

This was a retrospective cohort study that included monochorionic twin pregnancies observed in our center between March 2002 and June 2021, in which twins with a birthweight discordance of ≥20% were classified according to umbilical artery Doppler flow patterns of the smaller twin. We excluded cases with twin-twin transfusion syndrome and twin anemia polycythemia sequence. Monochorionic placentas of live-born twins were injected with dye, and images were saved for computer measurements of placental sharing and the diameter of anastomoses. Univariate linear regressions of the relationship between placental share discordance and birthweight discordance (both calculated as larger weight or share-smaller weight or share/larger weight or share×100%) and the relationship between arterioarterial and venovenous diameters and birthweight ratio/placental territory ratio were performed.

RESULTS

A total of 449 placentas were included in the analysis. Placental share discordance was positively correlated with birthweight discordance (β coefficient, 0.325; 95% confidence interval, 0.254-0.397; P<.0001). The arterioarterial diameter was negatively correlated with birthweight ratio/placental territory ratio (β coefficient, -0.041; 95% confidence interval, -0.059 to -0.023; P<.0001), meaning that an increase in arterioarterial diameter leads to less birthweight discordance than expected for the amount of placental share discordance. There was no relationship between venovenous diameter and birthweight ratio/placental territory ratio (β coefficient, -0.007; 95% confidence interval, -0.027 to 0.012; P=.473).

CONCLUSION

Birthweight discordance in monochorionic twins was strongly associated with placental share discordance. Large arterioarterial anastomoses can mitigate the effect of unequal placental sharing.

Gestational Age at Birth and outcome in Monochorionic Twins with Different Types of Selective Fetal Growth Restriction: A Systematic Literature Review

This systematic review aims to assess the gestational age at birth and perinatal outcome (intrauterine demise (IUD), neonatal mortality and severe cerebral injury) in monochorionic (MC) twins with selective fetal growth restriction (sFGR), according to Gratacós classification based on umbilical artery Doppler flow patterns in the smaller twin. Seventeen articles were included. Gestational age at birth varied from 33.0-36.0 weeks in type I, 27.6-32.4 weeks in type II, and 28.3-33.8 weeks in type III. IUD rate differed from 0-4% in type I to 0-40% in type II and 0-23% in type III. Neonatal mortality rate was between 0-10% in type I, 0-38% in type II, and 0-17% in type III. Cerebral injury was present in 0-2% of type I, 2-30% of type II and 0-33% of type III cases. The timing of delivery in sFGR varied substantially among studies, particularly in type II and III. The quality of evidence was moderate due to heterogenous study populations with varying definitions of sFGR and perinatal outcome parameters, as well as a lack of consensus on the use of the Gratacós classification, leading to substantial incomparability. Our review identifies the urgent need for uniform antenatal diagnostic criteria and definitions of outcome parameters. This article is protected by copyright. All rights reserved.

Selective Fetal Growth Restriction Type III: Application of a Recent Expert Consensus Definition

OBJECTIVES

Per a recent expert definition, diagnosis of selective fetal growth restriction (sFGR) in monochorionic diamniotic twins is based on an estimated fetal weight (EFW) <3% as sole criterion and/or combinations of 4 contributory criteria (1 twin EFW <10%; 1 twin abdominal circumference <10%; EFW discordance ≥25%; and smaller twin umbilical artery [UA] pulsatility index >95th percentile). We assessed these criteria in sFGR Type III (intermittent absent or reversed end-diastolic flow of the UA [iAREDF]) patients to test whether meeting the more stringent parameters of the consensus definition had worse outcomes, that is, progression to sFGR Type II (persistent AREDF) or twin-twin transfusion syndrome; or secondarily, decreased dual survivorship.

METHODS

This was a retrospective study of referred sFGR Type III patients (2006-2017). Patients were retrospectively categorized using consensus criteria for 2 comparisons: 1) EFW <3% versus remaining cohort; 2) EFW <3% or met all 4 contributory criteria versus remaining cohort.

RESULTS

Forty-eight patients were studied. Comparison 1: EFW <3% patients (58.3%) were not more likely to demonstrate disease progression (46.4% versus 65.0%, P = .2489) or worse dual survivorship (78.6% versus 85.0%, P = .7161). Comparison 2: EFW <3% or met all 4 contributory criteria (75.0%) patients were not more likely than the others to demonstrate progression (44.4% versus 83.3%, P = .0235) or worse dual survivorship (80.6% versus 83.3%, P = 1.0000).

CONCLUSIONS

In a referred cohort of sFGR Type III patients, there was no evidence that meeting more stringent parameters of the consensus definition was associated with disease progression or dual survivorship.

Prediction of fetal death in monochorionic twin pregnancies complicated by Type-III selective fetal growth restriction

OBJECTIVE

Monochorionic diamniotic twin pregnancies complicated by Type-III selective fetal growth restriction (sFGR) are at high risk of fetal death. The aim of this study was to identify predictors of fetal death in these pregnancies.

METHODS

This was an international multicenter retrospective cohort study. Type-III sFGR was defined as fetal estimated fetal weight (EFW) of one twin below the 10^th percentile and intertwin EFW discordance of ≥ 25% in combination with intermittent absent or reversed end-diastolic flow in the umbilical artery of the smaller fetus. Predictors of fetal death were recorded longitudinally throughout gestation and assessed in univariable and multivariable logistic regression models. The classification and regression trees (CART) method was used to construct a prediction model of fetal death using significant predictors derived from the univariable analysis.

RESULTS

A total of 308 twin pregnancies (616 fetuses) were included in the analysis. In 273 (88.6%) pregnancies, both twins were liveborn, whereas 35 pregnancies had single (n = 19 (6.2%)) or double (n = 16 (5.2%)) fetal death. On univariable analysis, earlier gestational age at diagnosis of Type-III sFGR, oligohydramnios in the smaller twin and deterioration in umbilical artery Doppler flow were associated with an increased risk of fetal death, as was larger fetal EFW discordance, particularly between 24 and 32 weeks' gestation. None of the parameters identified on univariable analysis maintained statistical significance on multivariable analysis. The CART model allowed us to identify three risk groups: a low-risk group (6.8% risk of fetal death), in which umbilical artery Doppler did not deteriorate; an intermediate-risk group (16.3% risk of fetal death), in which umbilical artery Doppler deteriorated but the diagnosis of sFGR was made at or after 16 + 5 weeks' gestation; and a high-risk group (58.3% risk of fetal death), in which umbilical artery Doppler deteriorated and gestational age at diagnosis was < 16 + 5 weeks' gestation.

CONCLUSIONS

Type-III sFGR is associated with a high risk of fetal death. A prediction algorithm can help to identify the highest-risk group, which is characterized by Doppler deterioration and early referral. Further studies should investigate the potential benefit of fetal surveillance and intervention in this cohort. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

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.

Outcome of monochorionic twin pregnancy complicated by Type-III selective intrauterine growth restriction

OBJECTIVE

Type-III selective intrauterine growth restriction (sIUGR) is associated with a high and unpredictable risk of fetal death and fetal brain injury. The objective of this study was to describe the prospective risk of fetal death and the risk of adverse neonatal outcome in a cohort of twin pregnancies complicated by Type-III sIUGR and treated according to up-to-date guidelines.

METHODS

We reviewed retrospectively all monochorionic diamniotic twin pregnancies complicated by Type-III sIUGR managed at nine fetal centers over a 12-year period. Higher-order multiple gestations and pregnancies with major fetal anomalies or other monochorionicity-related complications at initial presentation were excluded. Data on fetal and neonatal outcomes were collected and management strategies reviewed. Composite adverse neonatal outcome was defined as neonatal death, invasive ventilation beyond the resuscitation period, culture-proven sepsis, necrotizing enterocolitis requiring treatment, intraventricular hemorrhage Grade > I, retinopathy of prematurity Stage > II or cystic periventricular leukomalacia. The prospective risk of intrauterine death (IUD) and the risk of neonatal complications according to gestational age were evaluated.

RESULTS

We collected data on 328 pregnancies (656 fetuses). After exclusion of pregnancies that underwent selective reduction (n = 18 (5.5%)), there were 51/620 (8.2%) non-iatrogenic IUDs in 35/310 (11.3%) pregnancies. Single IUD occurred in 19/328 (5.8%) pregnancies and double IUD in 16/328 (4.9%). The prospective risk of non-iatrogenic IUD per fetus declined from 8.1% (95% CI, 5.95-10.26%) at 16 weeks, to less than 2% (95% CI, 0.59-2.79%) after 28.4 weeks and to less than 1% (95% CI, -0.30 to 1.89%) beyond 32.6 weeks. In otherwise uncomplicated pregnancies with Type-III sIUGR, delivery was generally planned at 32 weeks, at which time the risk of composite adverse neonatal outcome was 29.0% (31/107 neonates). In twin pregnancies that continued to 34 weeks, there was a very low risk of IUD (0.7%) and a low risk of composite adverse neonatal outcome (11%).

CONCLUSIONS

In this cohort of twin pregnancies complicated by Type-III sIUGR and treated at several tertiary fetal centers, the risk of fetal death was lower than that reported previously. Further efforts should be directed at identifying predictors of fetal death and optimal antenatal surveillance strategies to select a cohort of pregnancies that can continue safely beyond 33 weeks' gestation. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Outcome of monochorionic twin pregnancy with selective fetal growth restriction at 16, 20 or 30 weeks according to new Delphi consensus definition

OBJECTIVES

To report the outcome of selective fetal growth restriction (sFGR) diagnosed according to the new Delphi consensus definition, and determine potential predictors of survival, in a cohort of unselected monochorionic diamniotic twin pregnancies.

METHODS

This was a retrospective study of monochorionic diamniotic twin pregnancies followed from the first trimester onward, which were diagnosed with sFGR at 16, 20 or 30 weeks' gestation. sFGR was defined according to the new Delphi consensus criteria as presence of either an estimated fetal weight (EFW) < 3^rd centile in one twin or at least two of the following: EFW of one twin < 10^th centile, abdominal circumference of one twin < 10^th centile, EFW discordance ≥ 25% or umbilical artery pulsatility index of the smaller twin > 95^th centile. The primary outcomes were the overall survival rate (up to day 28 after birth) and risk of loss of one or both twins. We further determined possible predictors of survival using uni- and multivariate generalized estimated equation modeling.

RESULTS

We analyzed 675 pregnancies, of which 177 (26%) were diagnosed with sFGR at 16, 20 or 30 weeks. The overall survival rate was 313/354 (88%) with 146/177 (82%) pregnancies resulting in survival of both twins, 21/177 (12%) in survival of one twin and 10/177 (6%) in loss of both twins. Subsequent twin anemia-polycythemia sequence (TAPS) developed in 6/177 (3%) and twin-twin transfusion syndrome (TTTS) in 17/177 (10%) pregnancies. All TAPS fetuses survived. The survival rate in sFGR pregnancies that subsequently developed TTTS was 65% (22/34), compared with 91% (279/308) in those with isolated sFGR (no subsequent TAPS or TTTS) (P < 0.001). The majority of sFGR cases were Type I (110/177 (62%)) and had a survival rate of 96% (212/220), as compared with a survival of 55% (12/22) in those with Type-II (P < 0.001) and 83% (55/66) in those with Type-III (P = 0.006) sFGR. The majority of sFGR pregnancies (130/177 (73%)) were first diagnosed at 16 or 20 weeks (early onset), with a survival rate of 85% (221/260), as compared with a survival of 98% (92/94) in sFGR first diagnosed at 30 weeks (late onset) (P = 0.04). A major anomaly in at least one twin was present in 28/177 (16%) sFGR cases. In these pregnancies, survival was 39/56 (70%), compared with 274/298 (92%) in those without an anomaly (P < 0.001). Subsequent development of TTTS (odds ratio (OR), 0.18 (95% CI, 0.06-0.52)), Type-II sFGR (OR, 0.06 (95% CI, 0.02-0.24)) and Type-III sFGR (OR, 0.21 (95% CI, 0.07-0.60)) and presence of a major anomaly in at least one twin (OR, 0.12 (95% CI, 0.04-0.34)), but not gestational age at first diagnosis, were independently associated with decreased survival.

CONCLUSIONS

Isolated sFGR is associated with a 90% survival rate in monochorionic diamniotic twin pregnancies. The subsequent development of TTTS, absent or reversed end-diastolic flow in the umbilical artery of the smaller twin and the presence of a major anomaly adversely affect survival in sFGR. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Placental Anatomy and Function in Twin Gestations

With an increasing incidence of twin gestations, understanding the inherent risks associated with these pregnancies is essential in modern obstetrics. The unique differences in placentation in twins contribute to the increased risks. Monochorionic twins are susceptible to complications because of their unique placental architecture, including twin-to-twin transfusion syndrome, the twin anemia-polycythemia sequence, selective intrauterine growth restriction, and the twin reversed arterial perfusion sequence. Knowing the clinical correlations of placental anatomy in these gestations helps perinatal pathologists perform a more informed placental evaluation, allowing for better care for the mother and her children.

Impact of different prenatal management strategies in short- and long-term outcomes in monochorionic twin pregnancies with selective intrauterine growth restriction and abnormal flow velocity waveforms in the umbilical artery Doppler: a retrospective observational study of 108 cases

OBJECTIVES

To review perinatal and neurodevelopmental outcome (NDO) following selective fetoscopic laser coagulation (SFLC), cord coagulation (CC) or expectant management of monochorionic diamniotic twin pregnancies complicated with selective intrauterine growth restriction (sIUGR) and absent or reverse end-diastolic flow (AREDF) in the umbilical arteries (UA).

DESIGN AND SETTING

Single-centre retrospective observational study.

POPULATION

108 cases of sIUGR diagnosed before 26⁺⁶  weeks' gestation with AREDF in the UA.

METHODS

Survival rate and potential risk factors were analysed. NDO was assessed using parental questionnaires.

MAIN OUTCOMES MEASURES

Survival, gestational age at delivery and NDO.

RESULTS

SFLC, CC and EM were performed in 13, 50 and 45 cases, respectively, with an overall survival of 23.1, 40 and 77.8% and intrauterine demise of the co-twin of 30.8, 10 and 6.7% respectively. Intrauterine demise of the sIUGR twin occurred in 76.9 and 17.8% following SFLC and EM, respectively. The discordance in EFW at diagnosis was higher and absent/negative a-wave in the ductus venosus (DV) was more prevalent in the surgical groups. NDO in survivors at follow up was abnormal in 0 and 18% in the smaller twin following SFLC and EM, respectively, and in 25, 24 and 21% in the larger twin following SFLC, CC and EM, respectively.

CONCLUSION

SFLC yielded a poor result. EM seems a valid option when EFW discordance is <30% and a-wave in DV is positive. Otherwise, CC should be considered to protect the AGA co-twin. The long-term outcome of both small and large twins seems unaffected by the choice in primary prenatal management strategy.

TWEETABLE ABSTRACT

In type II sIUGR in MC twins, long-term neurodevelopment is normal in over 80% of the survivors.

Neonatal hair profiling reveals a metabolic phenotype of monochorionic twins with selective intrauterine growth restriction and abnormal umbilical artery flow

BACKGROUND

Selective intrauterine fetal growth restriction (sIUGR) in monochorionic diamniotic twins, especially types 2&3 with abnormal umbilical artery Doppler, results in increased risk of fetal/perinatal mortality and postnatal disability. We investigate whether the hair metabolome profiles of neonates were associated with the pathophysiological differences across the different clinical forms of sIUGR in twins.

METHODS

Hair samples were collected at delivery from 10 pairs of type 1 sIUGR twins, 8 pairs of types 2&3 sIUGR twins, and 11 pairs of twins without sIUGR. The hair metabolome was characterized using gas chromatography-mass spectrometry.

RESULTS

Our results demonstrated that the hair metabolite profiles of the different sIUGR subclinical forms were associated with the averaged fetal growth rate after 28 weeks of gestation but not with birthweight. The hair profiles were capable of discriminating type2&3 sIUGR twins from twins without sIUGR. In particular, the metabolites 2-aminobutyric acid, cysteine, alanine, and tyrosine all displayed areas under the receiver operating characteristic curve were above 0.9. The metabolic pathway analysis highlighted the associations of sIUGR twins with abnormal umbilical artery flow with increased metabolites from a nutrient depletion pathway, glutathione metabolism, and nerve development.

CONCLUSION

This study offers novel insight into the severity of intrauterine ischemia and hypoxia for T2&3 sIUGR twins, through evaluation of the neonatal hair metabolome.

A bibliometric analysis of Intrauterine Growth Restriction research

Intrauterine growth restriction (IUGR) is not a new subject in pregnancy. Nevertheless, this concept has newly begun to be integrated into pregnancy studies. We recognized articles that were published in English from 1977 to 2019 through electronic searches of the Web of Science™ database. The WoS database was searched for all published articles that compared preeclampsia from 1977 to January 2020. About 1469 documents in obstetrics and gynecology areas were analyzed in WoS database. VOSviewer software was employed to visualize the networks. The survey resulted in a 1469 published documents from 1977 to 2020. 'Gratacos' from Spain and 'Cetin' from Italy contributed the most publications. The greatest contribution came from the 'USA' (n = 498), 'Italy' (n = 155), and 'England' (n = 147). Furthermore, our results found that among these journals, the 'AJOG' (n = 318) and the 'Reproductive Sciences' (n = 209) published the largest number of papers. The top 100 most cited papers showed that 30% were reported in the 'AJOG'. About half the articles were published in the last decade and the most common studies were research paper (77%). The co-occurrence and co-citation analysis showed that the study formed four clusters. Finally, the strategic map was designed. We found that there existed an increasing trend in the large amount of publication on IUGR from 1977 to 2020. The number of studies in IUGR has substantially improved in the last decade. Authors from the 'USA' appeared the most proactive in addressing the IUGR area. By studying these articles, we propose important to support not only for grinding the IUGR challenges field but also for designing a new trend in this area.

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

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

Fetal therapies as standard prenatal care in Japan

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

Antenatal course of referred monochorionic diamniotic twins complicated by selective intrauterine growth restriction (SIUGR) type III

Objective: To describe the antenatal course of selective intrauterine growth restriction (SIUGR) type III patients.Study design: Retrospective study of monochorionic diamniotic twins with SIUGR type III. Patients were divided into those who did and did not progress to SIUGR type II or twin-twin transfusion syndrome (TTTS) (Groups A and B, respectively). Patient characteristics and perinatal survival were compared by Group, and continuous data are reported as median (range).Results: Forty-eight patients were studied; Group A [26 (54.2%)] and Group B [22 (45.8%)]. The difference in 30-day survivorship for the appropriate for gestational age twin (88.5 vs. 100%, p = .2394) and for the SIUGR twin (73.1 vs. 95.5%, p = .0551) was not statistically significant. However, dual survivorship was lower in Group A compared to Group B (69.2 vs. 95.4%, p = .0276).Conclusions: Approximately half of the SIUGR type III patients had antenatal progression. Lack of antenatal progression was associated with 95% dual survivorship.Rationale: The antenatal course of monochorionic diamniotic twins complicated by SIUGR type III is not well-understood and antenatal management remains a clinical dilemma. We provide pregnancy outcomes in a referred group of SIUGR type III patients, including the rate of progression to SIUGR type II and TTTS.

Management and perinatal outcome of selective intrauterine growth restriction in monochorionic pregnancies

Introduction: Selective intrauterine growth restriction (sIUGR) is a complication observed in about 10-15% of all monochorionic (MC) pregnancies, causing a significant increase in perinatal mortality and morbidity.Objective: To evaluate clinical management options and perinatal outcomes of sIUGR in MC pregnancies monitored in a single tertiary center.Methods: A retrospective study was performed on 55-MC pregnancies with sIUGR between January 2012 and May 2018 at the Fetal Medicine Unit of La Paz Hospital. Cases were classified according to the umbilical artery (UA) Doppler pattern as type I (positive end-diastolic flow; n = 25), type II [persistently absent or reversed end-diastolic flow (AREDF); n = 5] and type III [intermittently absent or reversed end-diastolic flow (iAREDF); n = 25]. Types II and III were then merged together as severe sIUGR cases. Subsequently, two possible approaches were considered: expectant management (EM) with elective preterm delivery in case of fetal deterioration, or in-utero therapy via fetoscopic laser photocoagulation (FLP) of intertwin anastomosis or selective umbilical cord occlusion (CO) of the growth-restricted fetus.Results: Gestational age (GA) at diagnosis was progressively lower with each type. Severe sIUGR cases delivered significantly earlier than type I, showing lower birth weights and higher intertwin biometric discordance. Unintended fetal demise occurred in 14% (6/25) of severe sIUGR pregnancies as opposed to 0% (0/19) in type I, p = .028. A significantly higher proportion of twins was admitted in NICU in severe cases when compared to type I [87% (33/38) versus 47% (18/38), p < .001]. In addition, brain damage at birth was also found to be more prevalent in this group [21% (8/38) versus 11% (4/38), p = .346], especially in the larger twin, when comparing any short-term neurological sequel [30% (7/23) versus 0% (0/19), p = .011] or specifically periventricular leukomalacia [PVL; 22% (5/23) versus 0% (0/19), p = .053]. Although the overall mortality rate was significantly higher in severe sIUGR that underwent CO instead of EM [58% (7/12) versus 11% (4/36), p = .002], NICU admissions were higher in the latter [94% (17/18) versus 40% (2/5), p = .021]. Neurological sequels at birth were similar in both groups [39% (7/18) versus 40% (2/5), p = 1.000], similarly when considering only the larger twin for any brain lesion [28% (5/18) versus 40% (2/5), p = .621] or just PVL [22% (4/18) versus 20% (1/5), p = 1.000].Conclusion: Given the good prognosis of type I sIUGR, expectant management is the first approach to consider. However, due to the poorer clinical evolution of types II and III sIUGR, the decision-making is challenging and needs to be individualized depending on the UA Doppler pattern, GA at diagnosis, severity of growth restriction and biometric discordance, technical issues and parents' preferences.

Prevalence of right ventricular outflow tract abnormalities among recipients in twin-twin transfusion syndrome after fetoscopic laser surgery in 90 consecutive cases

PURPOSE

Right ventricular outflow tract obstruction (RVOTO) is a severe complication in recipients in twin-twin transfusion syndrome (TTTS). This study investigated the prevalence of RVOTO in TTTS after laser surgery and examined the risk factors for RVOTO.

METHODS

This retrospective study evaluated 90 patients who had undergone laser surgery and been followed for 6 months after birth. The diagnosis of RVOTO was made based on postnatal echocardiography findings. Ultrasound and clinical records, including maternal and neonatal data, were retrieved from our database. Risk factors for developing RVOTO were compared between recipients with and without RVOTO in a statistical analysis.

RESULTS

Six surviving recipients were diagnosed with RVOTO. Three recipients had developed severe pulmonary stenosis (PS) that required percutaneous transluminal pulmonary valvuloplasty or balloon pulmonary angioplasty. A total of 6.7% of recipients (6/90) had RVOTO, consisting of PS and tricuspid regurgitation (TR), and 3.3% of recipients (3/90) required invasive treatment. The characteristic factors did not differ significantly between recipients with and without RVOTO.

CONCLUSION

This study revealed that 6.7% of recipients with TTTS had PS, and 3.3% required invasive treatment for PS. However, no significant association was noted between RVOTO development in recipients and maternal clinical data and fetal ultrasound examination findings. It is difficult to predict RVOTO development in recipients using only preoperative ultrasound and clinical information.

Perinatal outcome of monochorionic twin pregnancy complicated by selective fetal growth restriction according to management: systematic review and meta-analysis

OBJECTIVE

To explore the impact of severity and management (expectant, laser treatment or selective reduction) on perinatal outcome of monochorionic twin pregnancies complicated by selective fetal growth restriction (sFGR).

METHODS

MEDLINE, EMBASE, CINAHL, ClinicalTrials.gov and The Cochrane Library databases were searched for studies on outcome following expectant management, laser treatment or selective reduction in monochorionic twin pregnancies complicated by sFGR. Only pregnancies affected by sFGR and categorized according to the Gratacós classification (Type I, II or III) were included. The primary outcome was mortality, including single and double intrauterine (IUD), neonatal (NND) and perinatal deaths. Secondary outcomes were neonatal morbidity, abnormal postnatal brain imaging, intraventricular hemorrhage, periventricular leukomalacia, respiratory distress syndrome, admission to neonatal intensive care unit and survival free from neurological complications (intact survival). Meta-analyses of proportions were used to analyze the extracted data according to management, severity of sFGR and fetal size (smaller vs larger twin).

RESULTS

Sixteen observational studies (786 monochorionic twin pregnancies) were included. In pregnancies complicated by Type-I sFGR managed expectantly, IUD occurred in 3.1% (95% CI, 1.1-5.9%) of fetuses and 97.9% (95% CI, 93.6-99.9%) of twins had intact survival. In pregnancies complicated by Type-I sFGR treated using laser therapy, IUD occurred in 16.7% (95% CI, 0.4-64.1%) of fetuses and, in those treated using selective reduction, IUD occurred in 0% (95% CI, 0-34.9%) of cotwins, with no evidence of neurological complications in the survivors. In pregnancies complicated by Type-II sFGR managed expectantly, IUD occurred in 16.6% (95% CI, 6.9-29.5%) and NND in 6.4% (95% CI, 0.2-28.2%) of fetuses, and 89.3% (95% CI, 71.8-97.7%) of twins survived without neurological compromise. In Type-II sFGR pregnancies treated using laser therapy, IUD occurred in 44.3% (95% CI, 22.2-67.7%) of fetuses, while none of the affected cases experienced morbidity and survivors were free of neurological complications. Of pregnancies undergoing selective reduction, IUD of the cotwin occurred in 5.0% (95% CI, 0.03-20.5%) and NND in 3.7% (95% CI, 0.2-11.1%), and 90.6% (95% CI, 42.3-94.3%) of surviving cotwins were free from neurological complications. In pregnancies complicated by Type-III sFGR managed expectantly, IUD occurred in 13.2% (95% CI, 7.2-20.5%) and NND in 6.8% (95% CI, 0.7-18.6%) of fetuses, and 61.9% (95% CI, 38.4-81.9%) of twins had intact survival. In pregnancies complicated by Type-III sFGR treated with laser therapy, IUD occurred in 32.9% (95% CI, 20.9-46.2%) of fetuses and all surviving twins were without neurological complications. Finally, in pregnancies with Type-III sFGR treated with selective reduction, NND occurred in 5.2% (95% CI, 0.8-12.8%) of cotwins and 98.8% (95% CI, 93.9-99.9%) had intact survival.

CONCLUSION

Type-I sFGR is characterized by good perinatal outcome when managed expectantly, which represents the most reasonable management strategy for the large majority of affected cases. Pregnancies complicated by Type-II or -III sFGR treated with fetoscopic laser ablation have a higher rate of mortality but lower rate of morbidity compared with those managed expectantly, supporting the use of fetal therapy at gestations remote from neonatal viability. Data on outcome following selective reduction are scarce. In view of the lack of evidence from randomized controlled trials, prenatal management of sFGR should be individualized according to gestational age at diagnosis, severity of growth discordance and magnitude of Doppler anomalies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Prognosis of the co-twin following spontaneous single intrauterine fetal death in twin pregnancies: a systematic review and meta-analysis

BACKGROUND

Single intrauterine fetal death affects approximately 6% of twin pregnancies and can have serious sequelae for the surviving co-twin.

OBJECTIVES

Determine the prognosis of the surviving co-twin following spontaneous single intrauterine fetal death to aid counselling patients and highlight future research areas.

SEARCH STRATEGY

Medline, Embase, Web of Science, and Cochrane Library, from 1980 to June 2017.

SELECTION CRITERIA

Studies of five or more cases of spontaneous single intrauterine fetal death after 14 weeks gestation, in diamniotic twin pregnancies.

DATA COLLECTION AND ANALYSIS

Summary event rates were calculated and stratified by chorionicity. Monochorionic and dichorionic twins, and sub-groups, were compared by odds ratios.

MAIN RESULTS

In monochorionic twins, when single intrauterine fetal death occurred at less than 28 weeks' gestation, this significantly increased the rate of co-twin intrauterine fetal death [odds ratio (OR) 2.31, 95% confidence interval (CI) 1.02-5.25, I²  = 0.0%, 12 studies, 184 pregnancies] and neonatal death (OR 2.84, 95% CI 1.18-6.77, I²  = 0.0%, 10 studies, 117 pregnancies) compared with when the single intrauterine fetal death occurred at more than 28 weeks' gestation. Neonatal death in monochorionic twins was significantly higher if the pregnancy was complicated by fetal growth restriction (OR 4.83, 95% CI 1.14-20.47, I²  = 0.0%, six studies, 60 pregnancies) or preterm birth (OR 4.95, 95% CI 1.71-14.30, I²  = 0.0%, 11 studies, 124 pregnancies). Abnormal antenatal brain imaging was reported in 20.0% (95% CI 12.8-31.1, I²  = 21.9%, six studies, 116 pregnancies) of surviving monochorionic co-twins. The studies included in the meta-analysis demonstrated small study effects and possible selection bias.

CONCLUSIONS

Preterm birth was the commonest adverse outcome affecting 58.5 and 53.7% of monochorionic and dichorionic twin pregnancies. Outcomes regarding brain imaging and neurodevelopmental comorbidity are an important area for future research, but meta-analysis may be limited due to different methods of assessment.

TWEETABLE ABSTRACT

Preterm birth is the highest risk in single co-twin death. Abnormal antenatal brain imaging was found in 1/5 surviving MC twins.

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.

Ultrasound screening for complications in twin pregnancy

In the decades since the introduction of ultrasound into routine obstetric practice, the advantages of ultrasound have moved beyond the simple ability to identify multiple pregnancies antenatally to the possibility of screening them for fetal anomalies, pre-eclampsia, preterm birth, and the complications specific to monochorionic pregnancies. Screening studies have often excluded twins because physiological differences impact on the validity and sensitivity of the screening tests in routine use in singletons, and therefore, the evidence of screening performance in multiple pregnancy lags behind the evidence from singleton pregnancies. In general, most pregnancy complications are more common in twin pregnancy, but screening tests are less accurate or well validated. In this review article we present the current state of the evidence and avenues for future research relating to the use of ultrasound and screening for complications in twin pregnancies, including the monochorionicity-related pathologies, such as twin-twin transfusion syndrome, selective growth restriction, twin anaemia-polycythaemia sequence and twin reversed arterial perfusion sequence.

Fetoscopic laser photocoagulation for twin-twin transfusion syndrome

The aim of this study was to review fetoscopic laser photocoagulation (FLP), which ablates placental vascular anastomoses to treat twin–twin transfusion syndrome (TTTS). A review of studies reporting on the procedures, outcomes, complications and nonconventional applications of FLP for TTTS was conducted. FLP has been established as the primary treatment for monochorionic twin pregnancy associated with TTTS at 16–26 weeks. FLP is the only therapy that directly addresses the underlying pathophysiology. The recent technique modification of FLP, referred to as the ‘Solomon technique’, induces selective coagulation to connect the anastomoses ablation sites and has been introduced to reduce residual anastomoses. The perinatal survival following FLP improved significantly with advances in the technique after its introduction. The recent survival rates of both twins and at least one twin are 70% and more than 90%, respectively. However, there is still an 11–14% risk of long‐term neurodevelopment impairment. The premature rupture of membranes that leads to preterm labor is a common complication after FLP. FLP is a valuable treatment option for feto‐fetal transfusion syndrome in triplets and for TTTS after 26 weeks. FLP for selective intrauterine growth restriction may be potentially beneficial when accompanied by abnormal Doppler findings and oligohydramnios. FLP is the optimal treatment option for TTTS at 16–26 weeks of gestation. FLP appears to be applicable in triplets, TTTS after 26 weeks and cases of selective intrauterine growth restriction with abnormal Doppler findings and oligohydramnios. FLP is the most common and successful fetal intervention. Improvement in the neurodevelopmental outcomes after FLP is a future focus.

Type II and III Selective Fetal Growth Restriction: Perinatal Outcomes of Expectant Management and Laser Ablation of Placental Vessels

OBJECTIVES

To describe the perinatal outcomes of type II and III selective fetal growth restriction (sFGR) in monochorionic-diamniotic (MCDA) twin pregnancies treated with expectant management or laser ablation of placental vessels (LAPV).

METHODS

Retrospective analysis of cases of sFGR that received expectant management (type II, n=6; type III, n=22) or LAPV (type II, n=30; type III, n=9). The main outcomes were gestational age at delivery and survival rate.

RESULTS

The smaller fetus presented an absent/reversed "a" wave in the ductus venosus (arAWDV) in all LAPV cases, while none of the expectant management cases presented arAWDV. The median gestational age at delivery was within the 32nd week for expectant management (type II and III) and for type II LAPV, and the 30th week for type III LAPV. The rate of at least one twin alive at hospital discharge was 83.3% and 90.9% for expectant management type II and III, respectively, and 90% and 77.8% for LAPV type II and III, respectively.

CONCLUSION

LAPV in type II and III sFGR twins with arAWDV in the smaller fetus seems to yield outcomes similar to those of less severe cases that received expectant management.

Outcome of monochorionic twin pregnancy with selective intrauterine growth restriction according to umbilical artery Doppler flow pattern of smaller twin: systematic review and meta-analysis

OBJECTIVE

To explore the outcome of monochorionic twin pregnancies affected by selective intrauterine growth restriction (sIUGR) according to the umbilical artery Doppler pattern of the smaller twin.

METHODS

An electronic search of MEDLINE, EMBASE, CINAHL and ClinicalTrials.gov databases (2000-2016) was performed. sIUGR was defined as the presence of one twin with an estimated fetal weight and/or abdominal circumference < 10^th or < 5^th percentile and classified according to the umbilical artery Doppler flow pattern of the smaller twin (Type I: persistently positive; Type II: persistently absent/reversed; Type III: intermittently absent/reversed). Primary outcomes were perinatal mortality, intrauterine death, neonatal death and double fetal loss. Secondary outcomes were neonatal morbidity, including abnormal postnatal brain imaging, intraventricular hemorrhage, periventricular leukomalacia, admission to neonatal intensive care unit and respiratory distress syndrome, deterioration of fetal status, gestational age at delivery and degree of birth-weight discordance. A composite adverse outcome, defined as the presence of any mortality or abnormal brain findings, was also assessed. Quality assessment of the included studies was performed using the Newcastle-Ottawa Scale. A random-effects meta-analysis was used to compute the summary odds ratios (ORs), mean differences (MD) and proportions for the different outcomes.

RESULTS

Thirteen studies (610 pregnancies) were included. The risk of perinatal mortality was higher in twins affected by Type II compared with Type I sIUGR (OR, 4.1 (95% CI, 1.6-10.3)), whereas there was no difference among the other variants of growth restriction. Risk of abnormal postnatal brain imaging was significantly higher in twins affected by either Type II (OR, 4.9 (95% CI, 1.9-12.9)) or Type III (OR, 8.2 (95% CI, 2.0-33.1)) sIUGR compared with Type I sIUGR. The risk for neonatal intensive care unit admission was higher in Type II compared with Type I sIUGR (OR, 18.3 (95% CI, 1.0-339.7)). Twin pregnancies affected by Type I sIUGR were delivered at a significantly later gestational age compared with Type II (MD, 2.8 (95% CI, 1.83-3.86) weeks) and Type III (MD, 2.1 (95% CI, 0.97-3.19) weeks). The degree of birth-weight discordance was higher in Type II compared with Type I (MD, 21.6% (95% CI, 9.9-33.2%)) and Type III (MD, 9.3% (95% CI, 3.8-14.9%)) sIUGR.

CONCLUSION

Monochorionic twin pregnancies affected by Type II sIUGR are at a higher risk of perinatal mortality and morbidity compared with Type I. The likelihood of an abnormal outcome is usually not significantly different between sIUGR Types II and III, although the latter has an unpredictable clinical course. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Midtrimester isolated oligohydramnios in monochorionic diamniotic multiple gestations. J Matern Fetal Neonatal Med 2017;32:590-596. [PMID: 28965437 DOI: 10.1080/14767058.2017.1387530]

OBJECTIVE

To describe the natural history and perinatal outcomes of monochorionic diamniotic twins with midtrimester isolated oligohydramnios (iOligo).

MATERIALS AND METHODS

We performed a retrospective study of iOligo patients who were initially referred for the management of evolving twin-twin transfusion syndrome (TTTS) or selective intrauterine growth restriction (sIUGR). iOligo was defined as a maximum vertical pocket of amniotic fluid of ≤2 cm in the iOligo twin's sac and normal fluid level (>2 and <8 cm) in the co-twin's sac. "Group A" patients did not subsequently develop TTTS or sIUGR Type II (umbilical artery persistent absent or reversed end-diastolic flow), and "Group B" patients did develop TTTS or sIUGR Type II. Results are reported as median (range).

RESULTS

Of the 828 patients with complicated monochorionic twin gestations referred for possible TTTS or sIUGR, 36 (4.3%) were initially diagnosed with iOligo. After initial consultation, two patients terminated and one was lost to follow-up, resulting in a final study population of 33. Group A had 10 patients (30.3%) and Group B had 23 patients (69.7%). In Group A, nine of the 10 were expectantly managed, resulting in a median gestational age (GA) at delivery of 34.7 (18.0-36.4) weeks, a 30-day perinatal survival of at-least-one twin of 88.9% (8/9), and dual 30-day survivors in 8/9 (88.9%). In Group B, 12 (52.2%) developed TTTS and 11 (47.8%) developed sIUGR Type II. Fifteen Group B patients had laser surgery, resulting in a median GA at delivery of 33.7 (26.4-37.1) weeks, a 30-day perinatal survival of at-least-one twin of 100% (15/15), and dual survivorship of 46.7% (7/15).

CONCLUSIONS

Our findings show that the majority of patients with midtrimester iOligo have fetal growth restriction of the affected twin and subsequently progress to TTTS or sIUGR Type II.

Fetoscopic laser photocoagulation for amniotic fluid discordance bordering on twin-twin transfusion syndrome: Feasibility, perinatal and long-term outcomes

AIM

This study investigated the feasibility and safety of fetoscopic laser photocoagulation (FLP) for amniotic fluid discordance (AFD) bordering on twin-twin transfusion syndrome (TTTS) with an absent or reverse end-diastolic velocity (AREDV) in the umbilical artery (UA), and evaluated the perinatal and long-term outcomes.

METHODS

A prospective intervention study was performed between 20 + 0 and 25 + 6 weeks of gestation (UMIN000004165). AFD bordering on TTTS was defined as maximum vertical pocket (MVP) of amniotic fluid in one twin's sac ≤3 cm and amniotic fluid MVP in the other twin's sac ≥7 cm excluding TTTS. Neurodevelopmental outcome was evaluated at 6 months and at 3 years of age.

RESULTS

Eleven women were treated without complications between September 2010 and July 2011. In all cases amnioinfusion was required, with a median surgical time of 70 min. There were nine cases of selective intrauterine growth restriction in which the growth discordant rate was >25%. The survival rates of the donor and recipient twins were 27.3% (3/11) and 100% (11/11), respectively. None of the surviving donor twins and two of the 11 recipient twins had hemiplegia at 6 months of age. One additional recipient twin had developmental delay at 3 years of age.

CONCLUSIONS

Fetoscopic laser photocoagulation for AFD bordering on TTTS with AREDV in the UA was feasible without complications but frequently resulted in donor twin death and a high survival rate of the recipient twin, albeit with neurodevelopmental abnormalities in some cases. FLP does not seem to be a promising treatment option for AFD bordering on TTTS.

Fetal cardiovascular hemodynamics in twin-twin transfusion syndrome

Twin-twin transfusion syndrome (TTTS) complicates 10-15% of monochorionic-diamniotic (MCDA) pregnancies. It originates from unbalanced transfer of fluid and vasoactive mediators from one twin to its co-twin via placental anastomoses. This results in hypovolemia in the donor and hypervolemia and vasoconstriction in the recipient twin. Consequently, the recipient demonstrates cardiovascular alterations including atrioventricular valve regurgitation, diastolic dysfunction, and pulmonary stenosis/atresia that do not necessarily correlate with Quintero-stages. Selective fetoscopic laser photocoagulation of placental vascular anastomoses disrupts the underlying pathophysiology and usually improves cardiovascular function in the recipient with normalization of systolic and diastolic function within weeks after treatment. Postnatal studies have demonstrated early decreased arterial distensibility in ex-donor twins, but 10-year follow up is encouraging with survivors showing normal cardiovascular function after TTTS. However, prediction and appropriate early management of TTTS remain poor. Assessment of the cardiovascular system provides additional insight into the pathophysiology and severity of TTTS and may permit more targeted early surveillance of MCDA pregnancies in future. It should form an integral part of the diagnostic algorithm.

Selective reduction in complicated monochorionic twins: prediction of obstetric outcome and comparison of techniques

OBJECTIVES

To compare the outcomes of radiofrequency ablation (RFA) and bipolar cord coagulation (BPC) methods for selective feticide in complicated monochorionic (MC) twin gestations and to determine risk factors for adverse pregnancy outcome.

METHODS

This was a retrospective cohort study of all patients with complicated MC twin pregnancy who underwent selective reduction in a single tertiary care center between 2000 and 2014. We compared the two methods with respect to various demographic, obstetric and perinatal outcome variables.

RESULTS

Fifty-three selective terminations in complicated MC twin gestations were performed, 36 by RFA and 17 by BPC. Each technique resulted in a similar overall survival rate of the remaining twin (88.9% vs 76.5%, P = 0.25). Likewise, the mean procedure-to-delivery interval, the rate of spontaneous preterm delivery < 37, < 34, < 32 and < 28 weeks and the rate of preterm prelabor rupture of the membranes did not differ between the groups. However, among patients in the BPC group, there was a trend towards earlier gestational age at delivery (31.3 vs 35.0 weeks, P = 0.09) compared with in the RFA group. There was selective reduction by RFA due to selective intrauterine growth restriction (sIUGR) in 19 cases, 17 (89.5%) of which survived perinatally, with delivery at a median gestational age of 37 weeks. There were no significant differences in perinatal outcome, irrespective of whether the procedure was performed pre- or post-viability. All post-viability reductions, most of which were by RFA, resulted in perinatal survival.

CONCLUSIONS

Perinatal outcome of complicated MC twin gestations undergoing selective feticide seems to be similar regardless of whether termination is by BPC or RFA. Nevertheless, RFA appears to be particularly useful in MC twins complicated by sIUGR and in cases requiring selective reduction beyond the age of viability.

The North American Fetal Therapy Network Consensus Statement: Management of Complicated Monochorionic Gestations

The North American Fetal Therapy Network is a consortium of 30 medical institutions in the United States and Canada with established expertise in fetal therapy and other forms of multidisciplinary care for complex fetal disorders. This publication is the third in a series of articles written by NAFTNet about monochorionic pregnancies. In this article, we provide the general obstetric practitioner with information regarding management options available for complications of monochorionic gestations. This information may be useful for a better understanding of the pathophysiology of the various conditions, for better patient counseling, for timely referral to a regional treatment center, and for ongoing comanagement after treatment.

Feasibility and preliminary outcomes of fetoscopic laser photocoagulation for monochorionic twin gestation with selective intrauterine growth restriction accompanied by severe oligohydramnios

AIM

This study aimed to clarify the feasibility and perinatal outcomes of fetoscopic laser photocoagulation (FLP) for monochorionic twin gestation with selective intrauterine growth restriction (sIUGR) accompanied by both abnormal umbilical artery Doppler waveforms and isolated severe oligohydramnios of the sIUGR twin.

METHODS

In this prospective clinical trial, which included 10 cases with absent or reversed end-diastolic flow in the umbilical artery and severe oligohydramnios of the sIUGR twin, the main outcomes investigated were the feasibility of FLP and the rate of severe FLP-related maternal complications. The survival rate and incidence of neurological abnormalities of the twins at 28 days of age were also evaluated.

RESULTS

FLP was completed for all cases without major intraoperative maternal complications, although one case experienced threatened preterm labor requiring intensive treatment after the procedure. Three sIUGR and 10 larger twins were alive without neurological abnormalities at 28 days of age, while intrauterine fetal death occurred in the remaining seven sIUGR twins.

CONCLUSION

FLP for monochorionic twins with sIUGR, especially when accompanied by abnormal Doppler and severe oligohydramnios of the sIUGR twin, appears to be feasible and potentially beneficial for the larger twin, as well as for some sIUGR twins.

Cord Occlusion in Monochorionic Twins with Early Selective Intrauterine Growth Restriction and Abnormal Umbilical Artery Doppler: A Consecutive Series of 90 Cases

Objective: To describe perinatal outcomes achieved with cord occlusion (CO) in monochorionic twins with severe selective intrauterine growth restriction (sIUGR) and abnormal umbilical artery Doppler in the IUGR twin (types II and III). Methods: We studied a consecutive series of 90 cases of sIUGR with abnormal Doppler treated with CO of the IUGR fetus. Abnormal Doppler was defined as continuous (type II, n = 41) or intermittent (type III, n = 49) absent/reversed end-diastolic flow. All cases presented at least one of the following severity criteria: gestational age (GA) <22 weeks, inter-twin estimated weight discordance >35%, reversed end-diastolic umbilical artery flow or ductus venosus pulsatility index >95th centile. We prospectively recorded pregnancy course and perinatal outcome. Results: Median GA at surgery was 20.6 weeks and mean duration 22.4 min. Miscarriage (<24 weeks) occurred in 3.3% (3/90) and preterm delivery <32 weeks in 7.1% (6/84) of continuing pregnancies. GA at delivery was 36.4 weeks and neonatal survival of the larger twin was achieved in 93.3%. Conclusion: In a consecutive series studied by an experienced team, CO in monochorionic twins with severe sIUGR type II or III was associated with delivery >32 weeks in 92.9% and neonatal survival of the normal twin in 93.3% of pregnancies.