Twin gestation pregnancies: genetic counseling and testing experience.

We report on the prenatal genetic counseling and testing experience in 343 pregnancies with twin or higher multiple gestations. By self-report, 8% (27/343) parents of these pregnancies reported meeting with a genetic counselor, and 23% (79/343) elected prenatal genetic testing. The most common testing procedures elected were maternal serum analyte screening and amniocentesis to identify fetuses with aneuploidy or neural tube defects. Use of prenatal genetic testing was correlated with advanced maternal age. No association was found between use of genetic testing and use of OI/ART or the length of time needed to conceive. Forty percent (11/27) of those who met with a genetic counselor opted to decline prenatal testing/screening. These data suggest that although clients with multiple gestation pregnancies would likely benefit from genetic counseling, many are not availing themselves of this service. Implications of these data for the genetic counseling profession are discussed.