20 weeks is super early... It's amazing that he survived, usually the "viability" date is around 23 weeks, before this they don't "attempt miracles", your friend must have an amazing team of doctors and her son must have an awesome spirit and drive for survival.
I looked up stats for you... All I could find was that about 8% of babies are considered "premature" at birth (before 37 weeks) but I don't know how often this happens to babies as small as your friend's

Yeah.. I can't wait to get more info tomorrow. I just know the father call another one of my friend's all excited that his baby is home.... But you know men.... He never thought of asking for any details.

I'm 14 weeks.. I have a little belly.. I couldn't imagine giving birth in 5 weeks... No way will the baby be big enough then. But I guess we would be surprised. Babies are so strong.

Wow!! That's amazing!! I think bf was like around 24 weeks when he was born.. He was so tiny.. Hard to believe if you seem him now. They say that these little preemie boys turn out to be football players.. It was the case with mine.. He was a football player for a little while. Now he's a bodybuilder.

well, the very youngest survival on record is 19 weeks, 6 days. So 20 weeks must be rather astonishing. Such rare events are written up in medical journals, so I am curious as to the event. Can you get a reference?

Like I said, i'm going to try and get more info tomorrow. Normally I would have seen the father tomorrow, but he won't be attending the tournament we have because he wants to stay home with his new family ( I don't blame him). As soon as I have info i'll let you know. I'm very curious myself... And I always like to get my information directly from the source :) because you just never know about rumors :)