when i was seven weeks pregnant i picked up an eighty pound resident and hurt my back and the rn on duty at the time thought i was having a miscarriage however i was not able to have an xrays done till recently  and i  found out that i have retrolisthesis would you say it was caused by pregnancy or an injury from picking that resident up? I had no prior back problems
Well the cause of your issue could be anything out of what you think, but now you need to focus more on treatment as well as precautions.  For this you can visit an or tho or physio doctor get your mom done and based on the severity of your issue they will guide u in this with few posture related advice as well exercise to strengthen the back.  If it looks severe on MRI then the or tho would also guide for any kind of surgical corrections.  Don't get panic and just follow the steps by visiting or tho or physio, and you should be fine.  Take care