Supportive summer shoes?

[ComradeJing]

I'm pregnant and if this pregnancy is like the last one I'm going to need really supportive (is that a word? Or am I Making It Up?) shoes to avoid serious back ache.

Last time I lived in Birkenstocks but are there any other summer options about?

As an aside I'm convinced that wearing properly fitted and laced trainers in my last trimester stopped my feet spreading.