I would certainly involve your doctors. Some involvement to the optic nerve can be reversed but some MAY NOT - so you really need to be careful or you can risk permanent damage to your sight.
Please see your doctor ASAP.
I personally do not know about Macroadenomas. However, I do strongly encourage you to consult your doctors. Loss of side vision are visual field deficits and need to be closely monitored. I imagine you need to see a neuro opthamologist who can give you visual field tests and monitor changes to your vision as your pregnancy progresses.
My tumor is entirely different, but my presenting symptoms were vision loss when I was pregnant. Because you shouldn't have MRI's with contrast, visual field tests are a very safe and non-invasive way to track changes in the tumor while you are pregnant.
My vision loss presented early in the third trimester. At that point in time, the tumor was large enough to press on the optic nerve. My vision improved immediately after delivery. They claim my tumor growth has nothing to do with pregnancy, but that's more than a coincidence if you ask me. The neuro-opth also conducts other non-invasive tests to track my vision including color tests and OCT scans. Anyways, the moral of the story is that you should involve the doctors. My vision resolved with minor remaining deficits from the damage, but I do know of people whose did not. But know that a good neuro opthamologist has the technology to track changes in your vision without harming your baby. Since visual fields are safe and less expensive than MRI's, we continue to alternate MRI's and visual fields to track my tumor's progression.