In the season 12 episode "I Choose You", Alex's later-second wife (Camilla Luddington) finds an invoice from the fertility clinic that housed Izzie and Alex's fertilized embryos from when she had cancer and ponders the possibility that he has children with Izzie.
In season 12, episode "I Choose You", Alex's second wife (Camilla Luddington) discovers a fertility clinic invoice related to Izzie and Alex's embryos from when she was battling cancer. This prompts her to contemplate the possibility of Alex having children with Izzie.