When properly used as a diagnostic tool, ultrasound generally is considered safe. Lab studies, however, have shown that ultrasound does cause various physical effects in tissue (that's your baby we're talking about!), including a rise in temperature. While there is no evidence that these effects can harm your baby, medical experts agree that casual use of ultrasound should be avoided.

As with any medical procedure, if you want an ultrasound, talk to your healthcare provider.