Mirtazapine Remeron 33 weeks

I am pregnant week 33. Before pregnancy, I was taking Mirtazapine Remeron for my ADHD and it was extremely helpful to get a good sleep. I stopped few weeks before pregnancy and now I'm struggling so much to fall asleep because of stress and my sleep depreciation is impacting me a lot. I am worried this stress and sleep depreviation is bad for the baby. If I take remeron just for one night to get my sleep schedule back on track, would that be bad for thr baby?