On the one side are people completely unaware that most reproductive services include ultrasound diagnosis. Go in for a D&C, regardless of the reason (abortion or endometriosis or other reasons) and you are likely to get the same type of ultrasound complained of.
On the other side are people who discount completely the impact of choice or morality, or if they do, implicitly presume it. That is much like saying that people have sex, so the issue of consent or choice in sex does not matter. There is an issue of choice to have a procedure done and whether it is done for therapeutic or for coercive reasons.
I think consent, intent and purpose does matter, and I think the intrusions are, perhaps, close to unconscionable, regardless. Not to mention the potential link between autism and ultrasound http://en.wikipedia.org/wiki/Causes_of_autism#Other_in_utero -- I have qualms about the current use of ultrasound as entertainment as much as diagnostic tool in many settings.
Anyway, this is just a preliminary note, but I think the current debate needs to better incorporate these points.
There are several studies that indicate harmful side effects on animal fetuses associated with the use of sonography on pregnant mammals. A Yale study in 2006 suggested exposure to ultrasound affects fetal brain development in mice. A typical fetal scan, including evaluation for fetal malformations, typically takes 10–30 minutes. The study showed that rodent brain cells failed to migrate to their proper positions and remained scattered in incorrect parts of the brain. This misplacement of brain cells during their development is linked to disorders ranging from "mental retardation and childhood epilepsy to developmental dyslexia, autism spectrum disorders and schizophrenia." However, this effect was only detectable after 30 minutes of continuous scanning. No link has yet been made between the test results on animals such as mice and the possible effects on humans. Although the possibility exists that biological effects on humans may be identified in the future, currently most doctors feel that based on available information the benefits to patients outweigh the risks. The ALARA (As Low As Reasonably Achievable) principle has been advocated for an ultrasound examination — that is, keeping the scanning time and power settings as low as possible but consistent with diagnostic imaging — and that by that principle non-medical uses, which by definition are not necessary, are actively discouraged.