The argument I was responding to was that it was ok for DH to talk to his mother about his wife's depression but there was no need to talk about the termination. Like you I think they are linked and that therefore there was a need.
That apart, I think it is potentially really complicated.
If it is wrong to disclose the medical details re an abortion would it be wrong to disclose medical details re the depression?
If the depression had not been medically diagnosed would it be fine to discuss the depression? But would that have to stop the moment the depression was medically diagnosed?
I'm not suggesting that married couples should not share private matters nor keep confidences, but equally I am not sure that I support your/the position that because it started as her private medical information it can never be talked about by the husband.
The OP did not have to disclose her pregnancy or her termination to her DH. She chose to tell him. Once she did, she made her private information public. It is no longer private medical information.
Having made her choice she wants to limit her husband's choices. Is that acceptable or is it controlling? It might be both. It is obviously controlling, but it might also illustrate that there are circumstances in which a good spouse allows him/herself to be controlled.
Often we need to unburden ourselves and share our problems with another. Once our problems and burdens have become their problems and burdens, why do they then not have the same right to unburden and share their problem?
I accept that the OP instructed her DH not to talk about the termination. But does she have any right to do that? And if she does is it an absolute right? What if DH thought OP was a suicide risk because of depression stemming from a termination. Would that allow him to discuss the termination with someone he trusted?
I apologise OP for turning your pain into a series of possibly irrelevant questions, but in all honesty I find this general situation very difficult.
I don't know if your DH is being a good person or not. He might be at the end of his tether, genuinely worried about you, your health and your/his marriage. In that situation if I was him, I would probably include the termination in the discussion with my mother. But even then, context is important. If my mother was vehemently anti-abortion or anti-you, I would find a more suitable 'confidant'.
But if I knew my mother loved you, wanted what was best for you and wouldn't judge you for having a termination then I might well discuss everything if in doing so I could help save our marriage.