11.   But the FDA questioned if radiation also prevented heart attacks and deaths, or if the procedure might cause heart attacks.

12.   In some cases this procedure causes small blood clots, cholesterol crystals or other bits of debris to break free.

13.   The procedure can cause hemorrhaging, scar tissue, large cysts, sexual difficulties and problems in childbirth.

14.   U.N. officials said they did not know if the new testing procedure had caused any infections, since they had only learned of it in recent weeks.

15.   It is uncertain how the procedure causes harm, but it likely alters blood flow to the brain in babies with low blood pressure, Harding said.