Lyretail males normally cannot reproduce due to the deformed fins, which is why I ask. I've not read anything about female lyretails having problems reproducing, however.
The balloon variety is also a deformity that caused a curved spine. I've heard of issues with bloating and constipation with balloon versions due to the deformity, so its possible it may cause problems with giving birth with females as well. If the female IS pregnant and for some reason cannot give birth, she should be ok. Normally the fish will reabsorb the developing fry if they can't be born.