title: Invasive diagnostic procedures in twin pregnancies.
abstract: The rising rate of multiple pregnancies and its association with advanced maternal age has expanded the need for prenatal diagnosis in twins and higher order gestations. The complexity of the invasive diagnostic procedures and the risk of loss of an unaffected twin raise significant clinical, technical and ethical issues. In this review we discuss the specific issues of early scanning, counseling and determination of chorionicity prior to invasive procedures in twins. We present the available data describing the risk associated with these procedures in twins and compare data of fetal loss rate from different studies. We also discuss the issues of fetal blood sampling and late karyotyping in twin pregnancies.
authors.affiliation: Department of Obstetrics and Gynaecology, University College London, Chenies Mews, London, UK. b.weisz@ucl.ac.uk
authors.forename: Boaz
authors.initials: B
authors.lastname: Weisz
authors.forename: Charles H
authors.initials: CH
authors.lastname: Rodeck
mesh_terms: D000649:Amniocentesis / Q000379:methods*; D002823:Chorion / Q000000981:diagnostic imaging*; D015193:Chorionic Villi Sampling / Q000379:methods*; D005260:Female; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014427:Twins; D014463:Ultrasonography