My son was estimated to be over 10lb before birth and he came out 7lb 1oz, the measurements can be so off so I wouldn’t say it was anything you did.
My baby girl came out at 6lb 5oz and at 37 weeks and they thought she’d be big x
Yup it can happen. My son born in December was “supposed” to be bigger than my 1st (8lbs 6oz), but when he was born he was only 7lbs 6oz. I did notice that all throughout my pregnancy my belly was measuring ahead by 2-3 weeks, but towards the end my belly had stopped growing and I was measuring back on track. It could have to do with the placenta deterioration or the fact that insulin levels start to even out towards the end. Hard to say. I don’t think it was caused by you “cutting back” unless you really weren’t getting enough calories
I was eating 3 meals a day and snacks as told by the nurse. So it must’ve just been either the placenta deterioration as I have read up about that or just the measurements being super off. My belly always measured relatively on track too. Just one of those things I guess!
GD can also cause smaller babies - they focus on larger babies as that’s where the increased risk for birth injury is. But also, scans aren’t always a perfect means of measurement so could be that too!