In the Mishneh Torah הלכות אישות פרק טו, ב Rambam requires a man to who hasn't had a male and female child and whose wife has not given birth for ten years since their marriage to either take a second wife for the purpose of fulfilling "be fruitful and multiply" or divorce the wife.
Do other Rishonim list this or a similar requirement, or is it only Rambam? If other Rishonim discuss it, what do they say?
Others discuss the braisa in Yevamos 64a which is the source of the Rambam. See tosafos there d.h. af al pi. See also in maseches Ksuvos 77a tos. d.h. lisni.
See also the Tur in Even Ha'ezer siman 1 siff 3 with Darkei Moshe And Shulchan Aruch with Ramma there in the name of shu't Rivash siman 15 who says we no longer enforce this.