Ultrasound is the only way to determine cord placement. As for seizures it is highly unlikely. Even if it does happen since the brain is still developing it won't be an indicator of if seizures will occur outside the womb.
I actually looked it up and it does happen. Drs mistake them for the hiccups. Its not often but it does happen. And it can cause problems when they come out.
I honestly don't believe that it's capable for a fetus to have a seizure. I'm sure that your baby is just having hiccups.
Also is there any way to know the umblilcal cord is wrapped around the babys neck besides an ultra sound?