The challenge of prenatal diagnosis in twin pregnancies

The need for prenatal diagnosis in multiple gestations has expanded greatly as a result of the advancing maternal age of many patients, as well as the increased use of artificial reproductive techniques (ART). Twin gestations pose unique issues in prenatal diagnosis. The performance of Down syndrome screening is altered, invasive testing is more complex and poses a greater risk, and there are unique ethical and counselling issues. These issues are of increasing importance, and this article will review the background and current literature regarding the methods available for prenatal diagnosis and screening in multiple gestations. Surprisingly, recent investigations on this topic are limited despite its increasing pertinence to clinical care. Therefore, we have attempted to integrate the practices on the basis of both older and newer data.