Isolated polyhydramnios in the third trimester or polyhydramnios secondary to late-onset gestational diabetes: is it worth distinguishing?

Polyhydramnios in late pregnancy without evidence of pregnancy-related causes leading to polyhydramnios may be a sign of late-onset gestational diabetes mellitus in women with a normal prior oral glucose tolerance test. As pregnancy outcomes and management were indifferent, it does not seem necessary or useful to diagnose whether or not late-onset gestational diabetes mellitus is present.