As others pointed out, the statement "many women grow extra sets in their uteruses" is misleading at best. The kind interpretation is that you are thinking of

As others pointed out, the statement "many women grow extra sets in their uteruses" is misleading at best. The kind interpretation is that you are thinking of Teratoma (mentioned above). The less kind is that you are thinking of that cheesy black-comedy horror movie from the 2000s.