I had a similar problem with Golden Care recently where someone moved over here who was pregnant.

They just refused her totally for any insurance.

The thing is that these student insurances are supposedly the equivalent of the LAMal (or basic) insurance meaning that they don't refuse you for pre-existing conditions or being pregnant etc.

As I've mentioned before, I only work with Student Care as they are affiliated with a "proper" Swiss insurance (CSS). It is the same kind of thing as Swisscare and Golden Care (80.-/month ; annual deductible of 100.-).
I called them about this issue and they confirmed that there is no refusal for pre-existing conditions or pregnancy.

This means that anyone becoming pregnant on their policy or pregnant before getting it is covered 100% in a cantonal hospital (i.e. not in a private ward) - just like basic insurance covers.

I have no direct experience of Swisscare so if anyone has had any similar issues, I'd be interested to hear about them.