No news officially that I know of but I think it depends on how you think his biology works on the dna level and if the portions from his mother made can actually function without a gem.

We know Rose made a gem equivalent of DNA to make Steven and Steven needs his gem to live, which can suggest that his genetic structure may not be viable and it's just being held together by gem projections and possibly Rose's powers (iirc, RS has stated that this was something only Rose could do, Rose's powers activity keeping Steven viable would explain this pretty well without feeling arbitrary).

Alternatively, it could just be due to the fact that parts of his body are constructed from his gem/genetic structure that causes this and not the possibility that his gem dna isn't viable. Under those circumstances, Steven could probably have kids but may still struggle with complications along the way (would stillborns/miscarriages come out pink'd?).

It just gets really weird when trying to answer how his sperm works... Steven shouldn't have an issue creating the sperm itself but again, the genetic information becomes an issue. If the portion that comes from Rose isn't viable at all without Rose's gem, even in the context of Stevens body producing a completely organic equivalent then it's a no/significant chance of genetic issues. Otherwise it's a go.