Take a look at this from Šumma Izbu tablet I, omen 50.
There are actually a couple of omens in Šumma Izbu that mention a women giving birth to wind (SAL IM Ù.TU, amīltu šara ulid).
Now look at this from Isaiah 26:18,
We were with child, we writhed –
It is as though we had given birth to wind (יָלַדְנוּ רוּח);
We have won no victory on earth;
The inhabitants of the world have not come to life?
It’s hard not to see a reflex of the Šumma Izbu omen in Isaiah 26:18.
I now need to see if anyone else has noticed this. I also need to take a closer look at the last clause of Isaiah 26:18 (וּבַל-יִפְּלוּ יֹשְׁבֵי תֵבֵל).