Patau syndrome and perinatal decision making.

Mariana López, 18, is 6 months pregnant with her first child. A routine screening ultrasound at 20 weeks demonstrated a constellation of severe fetal defects, including a structural brain anomaly, multiple heart defects, and an abdominal wall defect. Concerned about a possible genetic syndrome, Ms López’s obstetrician, Dr Sarah Wilson, scheduled an amniocentesis, which confirmed trisomy 13 (Patau syndrome). Dr Wilson informed Ms López and her parents, with whom she lived, that the fetus had a severe genetic anomaly, and that the prognosis was poor. Eighty percent of affected infants die within the first month of life, only 5 percent survive the first 6 months. Those who survive past the first year have severe mental deficiency and seizures and fail to thrive.