He kept his girl parts because the SRS for FtM TS (god that's a lot of abbreviation) doesn't produce very good results. He never had any intention of getting pregnant when he began his transition, it's just his wife proved utterly infertile.
So after what was I'm sure an incredible amount of soul searching (for a TS to embrace a part of themselves they feel should never have been there in the first place), he halted his transition and began attempts to become pregnant himself. Took a long time, including at least one miscarriage. Frankly, I'm surprised it even worked at all. I had been under the impression that monthly cycles never began again for physical women who took testosterone (be it FtMs or misguided Eastern European athletes in the 1980s).