If one has hiccups, and needs to make a beracha, is it a problem?
There are high chances that some words will be split and mispronounced...
Halachipedia has the laws of Birkat Hamazon. Hiccups are not mentioned but the following seems relevant:
Someone who is drunk
One may say Birkat HaMazon even if one is slightly drunk and is unable to speak properly but still would be able to speak before a king, however, if one is unable to speak properly and can’t speak before a king one should try to say Birkat HaMazon before reaching that point, but one may still say Birkat HaMazon. [S”A 185:4-5, Mishna Brurah 185:6]
I deduce that if you would not speak before a king with hiccups like that, it is better (in this case) to wait till the hiccups go (assuming it is within the time to still say Birkat HaMazon – see the relevant halochos). But one may still say Birkat HaMazon. Of course CYLOR.