Early imaging predictors of fetal cerebral ischemic injury in monochorionic twin pregnancy complicated by spontaneous single intrauterine death

Monochorionic Twin Complications and Fetoscopic Interventions

Monochorionic twins are at risk for complications due to the presence of placental vascular anastomoses, including twin-twin transfusion syndrome, twin anemia-polycythemia sequence, selective fetal growth restriction, and twin reversed arterial perfusion sequence. While ultrasound is the primary modality to screen for the development of these complications, MRI plays an important role in assessing monochorionic twin pregnancies for the development of other complications, such as neurologic injury. In this article, the authors review the ultrasound imaging findings associated with monochorionic twin complications, management options, and the role for MRI in these pregnancies.

Twin Gestation With Spontaneous Reduction To Singleton

Twin gestations are at increased risk of single intrauterine fetal death. A first-trimester loss is a common complication in twin gestations. The rate of co-twin morbidity and mortality is higher when a single demise occurs in the second and third trimesters. Monochorionicity strongly influences the prognosis for the surviving co-twin. Fetal ultrasound combined with MRI may be able to help predict neurological injury to the surviving co-twin. The rate of co-twin demise decreases with advancing gestation. After single intrauterine fetal demise, monochorionic gestations should be delivered by 34 weeks and dichorionic by 36 to 37 weeks gestation.

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.

Fetal growth disorders in twin gestations

PURPOSE OF REVIEW

Twin gestations account for approximately 3% of all births. Although there appear to be physiologic differences in the third trimester growth of twins compared with singleton gestations, reasons for this remain unclear. As growth-restricted fetuses and neonates are at increased risk for adverse outcomes, there is a clinical need to optimize our ability to delineate normally from pathologically grown twins.

RECENT FINDINGS

Recent studies have addressed current limitations in the way growth restriction is diagnosed in twin gestations. Twin-specific fetal and neonatal growth charts have been shown to decrease the number of cases inappropriately labeled as growth restricted compared with singleton nomograms. In addition, individual growth assessment (IGA) is a promising method of diagnosing pathological growth using each fetus's growth potential rather than a comparison of the estimated fetal weight with population nomograms.

SUMMARY

There is a recent focus on improving our understanding of physiologic and pathologic twin growth. The increased use of twin-specific growth curves is likely to result in a decrease in the incidence of FGR diagnosis among twin gestations and could improve the outcomes of twins currently misclassified as FGR. Future research will hopefully clarify the reasons behind differences seen in twin versus singleton third trimester twin growth.