I'll play devil's advocate here. My daughter has CIs, and while I'm not minimizing surgery on a baby, she rebounded and healed tremendously well. I know not all cases are like that, but she was back to her happy, walking, playing self that same night after the surgery, albeit a little calmer and sleepy. She was 12 months, to the day, with her first implant, and 14 months with the second. The ENT used a facial nerve monitor to ensure he kept clear of it, as paralysis of the implanted side of the face is a risk, a very scary one. She has half-moon scars behind her ears, one's a little more wobbly than the other; I assume its because the ENT had a better hand on one side versus the other, like all of us. Her hair's growing back and covering the scars, though. Her surgeries were on a Friday and we were back to daycare and work by Monday. They're babies, they heal incredibly fast. Its unfortunate she couldn't tell us if she was in pain or had headaches or anything, but we gave her a small dose of liquid painkiller the first and second day, and regular children's Tylenol by Sunday. She nursed at the time, so I know that helped a lot with the comfort and her sleeping soundly.
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We did lots of research on both sides of the debate with her CIs. We are firm believers in ASL and deaf integration for her. The CIs are just a tool and when she's had enough for the day, we take them off and don't force her to wear them. There are some moms that INSIST their babes wear them 24/7; that's not us. If she decides not to wear them when she's older, that's fine with us, too. Its her body, her life. BUT, that being said, by waiting and not doing the surgery when she's pre-lingual, success rates plummet and while the kids make their own decision to get them when they're older, a lot of kids aren't happy and don't wear them, then they're a waste. CIs are much more effective and a valuable tool when the child is implanted before they acquire speech and while their brain is still developing. By not doing it before 3 years old and letting the kid decide when they're older, you are essentially making the decision for them.
All that being said, I can't stress enough, again, how important it is for her to do her own research.