Invasive genetic studies in multiple pregnancy

Invasive procedures for prenatal diagnosis in multiple gestations are relatively safe and effective. First-trimester chorionic villus sampling has a lower risk of procedure failure and of fetal loss than amniocentesis but it carries a higher risk of maternal cell or twin-twin cell contamination. In experienced hands, the safety, efficacy of sampling and accuracy of genetic analysis of chorionic villus sampling and amniocentesis are similar. We describe our experience in amniocentesis, chorionic villus sampling and cordocentesis in multiple pregnancy.