Observed Rate of Down Syndrome in Twin Pregnancies.

Obstet Gynecol

Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, and the Division of Medical Genetics, Department of Pediatrics, University of California, San Francisco, San Francisco, and the Genetic Disease Screening Program, California Department of Public Health, Richmond, California.

Published: November 2016