I think the legal motive would look for malicious intent, not “risk” or knowing risk unless that activity pretty close to 100% of the time causes harm such as illicit drug use or alcholism.
I think about a prosecutor with an agenda like the guy in Texas who went after Delay. A woman and her family shouldn’t have to spend their life savings to defend themselves against an overzealous prosecutor trying to sabatoge a constitutional amendment intended to protect the unborn from abortion.
What about legitimiate drugs that harm the fetus but help the mother? What if the mother has cancer and needs chemotherapy or she'll die. Chemo kills a fetus. But wait, under this law, the fetus is a person so killing the fetus would be murder. Under the law, you can't take one person's life to save another, so sorry, mom, you'll have to die of cancer (and probably your fetus with you).
It's a ridiculious example, but that's because this is a ridicuious proposal. Colorado would have to spend decades amending its statutes and changing case law to conform to this new definition and they'd still never get it right. Better just fight the fight head on and get Roe repealed. Like I said above, tricks like this just don't work.