Effects of shock waves on the mouse fetus

Extracorporeal shock wave lithotripsy is contraindicated during pregnancy because its effects on the fetus remain to be ascertained. The purpose of this study was to elucidate the effects of shock waves on fetuses at various stages of pregnancy. Pregnant mice received 100, 250, or 500 shock waves on 8, 10, 12, 14, and 16 days postcoitum. The effect on fetal survival rate and weight was minimal in the early stages of pregnancy. In the later stages of pregnancy, however, the number of viable fetuses decreased in proportion to an increasing number of shock waves, and almost no viable fetuses were found in the group treated with 500 shock waves. Fusion and necrosis were found in many dead fetuses. Histological examination of the fetuses, which was obtained immediately after the shock wave treatment, revealed hemorrhages in the brain, lungs and subcutaneous tissue. This study indicated that shock waves lead to fetal damage and death in the late stage of pregnancy in mice.