title: Early pregnancy assessment in multiple pregnancies.
abstract: Early ultrasound assessment and accurate determination of chorionicity is crucial so that appropriate care of multiple pregnancy can be provided. It is best achieved in the first trimester of pregnancy using the Lambda 'λ' and 'T' signs. Accurate labelling of the twins is needed to ensure that the same individual fetus is measured through the pregnancy so that the longitudinal growth pattern can be correctly assessed. Discrepancy in crown-rump length indicates a possibility for future development of selective intrauterine growth restriction. Careful early ultrasound assessment is needed to identify structural and chromosomal anomalies, as twin pregnancies are at increased risk. Twin-to-twin transfusion syndrome, selective intrauterine growth restriction and congenital abnormalities represent the major determinants of perinatal loss in monochorionic pregnancies, and diagnosis and prognosis are discussed in detail. Treatment of twin reverse arterial perfusion sequence is more effective in early pregnancy, so early identification is needed. Outcome of conjoined twins is guarded, and is dependent on the extent of fusion, degree of sharing of organs, associated anomalies, and presence of cardiac failure in utero.
authors.affiliation: Fetal Medicine Unit, Division of Developmental Sciences, St George's University of London, London SW17 0RE, UK.
authors.forename: Francesco
authors.initials: F
authors.lastname: D'Antonio
authors.affiliation: Fetal Medicine Unit, Division of Developmental Sciences, St George's University of London, London SW17 0RE, UK. Electronic address: abhide@sgul.ac.uk.
authors.forename: Amar
authors.initials: A
authors.lastname: Bhide
mesh_terms: D025063:Chromosome Disorders / Q000000981:diagnostic imaging; D000013:Congenital Abnormalities / Q000000981:diagnostic imaging; D018568:Crown-Rump Length; D042241:Early Diagnosis; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011272:Pregnancy, Multiple; D018570:Risk Assessment; D012307:Risk Factors; D014430:Twins, Monozygotic; D016216:Ultrasonography, Prenatal
keywords: prenatal diagnosis; twin pregnancy; ultrasound