'Feels very invasive' strikes me as an odd thing to say, given the fact that you would have been lying on a table starkers under strategically placed bits of material. Surgery is invasive
This is not the first time this week I've seen posters with little understanding of the principles of consent and frankly I'm finding it appalling.
The op, understandably, is confused and worried - disconcerted- by an intimate disrobing while she was unconscious and at a time when she was, by the nature of being in hospital, pregnant and undergoing surgery, immensely vulnerable.
if she was implying sexual assault, which I don't think she was, I'm astounded that people would leap to judgement against her when many events - some very recent indeed - have shown time and time again that woman should not trust authority or care figures implicitly.
I am not suggesting for a minute that the op was the victim of anything untoward, I don't believe she was suggesting it either. But I'm astonished that just because some people wouldn't be bothered to find themselves without knickers following a GA they should think it strange that someone else does.
As pp have said, the op should have been made aware before going under and I'm sure be fully reassured by nurses in the morning.
...I'm putting my soapbox away now!