Screening for Aneuploidy in Twins

Abstract All pregnant women should be offered screening for aneuploidy. Twin pregnancies present unique challenges in aneuploidy screening. This review describes available aneuploidy screening options and their benefits and limitations in twin pregnancy, in addition to describing special circumstances such as vanishing twins and diagnostic testing in twin pregnancy. No method of aneuploidy screening is as accurate in twin pregnancies as singletons. Cell-free DNA screening should be considered first-line, however this option may not be available or may have limitations in certain clinical scenarios such as vanishing twins. If cell-free DNA screening is not available, nuchal translucency and/or maternal serum marker screening can be offered.