Prenatal aneuploidy screening has changed dramatically in recent years with increases in the types of chromosomal abnormalities reliably identified and in the proportion of aneuploid fetuses detected. Initially, screening was available only for trisomies 21 and 18 and was offered only to low-risk pregnancies. Improved detection with the quadruple- and first-trimester multiple marker screens led to the option of aneuploidy screening for women 35 years of age and older. Cell-free DNA tests now screen for common autosomal trisomies and sex chromosome aneuploidies. Cell-free DNA screening is particularly effective in older women because of higher positive predictive values and lower false-positive rates. Integrated first- and second-trimester multiple marker tests provide specific risks for trisomies 21, 18, and possibly 13, and may detect an even wider range of aneuploidies. Given current precision in risk assessment, based on maternal age and preferences for screening or diagnostic tests, counseling has become more complex. This review addresses the benefits and limitations of available aneuploidy screening methods along with counseling considerations when offering them.
Benefits and limitations of different aneuploidy screening options vary according to maternal age and patient wishes, making counseling complex.
Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, and Parkland Hospital, Dallas, Texas.
Corresponding author: Jodi S. Dashe, MD, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9032; e-mail: email@example.com.
Financial Disclosure The author did not report any potential conflicts of interest.
Continuing medical education for this article is available at http://links.lww.com/AOG/A805.