It should be easy enough to see whether evidence speaks for use of scans, or is indifferent.
What adverse outcomes in what number have been associated with abortions without using imaging technology to confirm gestational age? How great is the reduction of these adverse outcomes, since routine imaging has been introduced?
And even if there's a solid evidence base favouring u/s, firstly, shouldn't a woman be able to still refuse it, as an [i]informed[/i] decision, i.e. be presented all the risks and benefits and then decide how to proceed?
Also, if there was a genuine reason, that this was medical best practice, would there be a need to enshrine it into a law, at the decision making stage?
Routine u/s is best practice in continuing pregnancies, but there is no law which obliges a woman to agree to it.