From what I recall, fairly accurate on my later 2 kiddos. I think they were both charting to be about 3.5-4 lbs and they both ended up about 4-4.5 lbs...although Marcel is so freakin' cobby that he looks more like a 3 pounder. He's ALL MAN though, to be clear
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Looks like your kiddo may reach somewhere around 5 lbs, which is a great size. Some say the 12 week estimation is more accurate, but who knows.