Trisomy 16 detected at chorion villus sampling

Trisomy 16 detected at chorion villus sampling (CVS) may reflect the placental but not the fetal karyotype. We describe a case in which the pregnancy continued until intrauterine death at 37 weeks. Cytogenetic study of two placental samples showed 47, + 16 and 46,XX; the fetus was morphologically grossly normal, but fetal tissue culture was unsuccessful. Conservative management may be appropriate when trisomy 16 is detected at CVS and the pregnancy is normal ultrasonographically.