It has been going on for a while and we had a couple of members who started as children MTF and FTM, reached adulthood and went off them long enough to have a child. As long as you receive sufficient medical monitoring, they can be relatively safe. In addition, we have other member who are unable to get surgery or don't desire it but remain on the blocker provided as a part of HRT. There are few if any issues reported with this approach either.