My ds floats around the 0.4th centile and sometimes just below. He was 9th centile when born and has only ever lost weight once, he gained fine for the first 8 weeks then slowed down and has gained slowly ever since.
He is now 14 and a half months old and fit and healthy. He has been refered to the paediatrician ages ago and he keeps saying ds is fine but we go back for regular check up's to check how he's getting on. He was also refered to the dietician for ideas on how to up his calorie intake.
I bf him for 5 weeks, gave up for a week, started again but still had problems so he was mix fed till 5 months (all the time I was pressure to give more formula than I was giving by the hv, I kept insisting I didn't want to lower my milk suppply by doing this, eventually ds got more used to bottles and wouldn't bf . I have since found out he has an undiagnosed slight tongue tie which may have affecting him latching on). Just for the record, his weight gain was no different on formula than it was when he was bf at all! Oh, and breast milk has more calories than formula anyway.
By the time we saw the dietician he was ff so she prescribed slightly higher calorie formula which helped a little bit. As he wasn't moving up the centiles on that she prescribed an even higher one at 1yr old and thins helped a bit more but also had the efect of making him sick once a day and putting him off solids completely . He is now on a mixture of the old high calorie and the new high calorie.
He's doing well but I have to say, this is just how he's made, he has always had a small appetite when bf ff and fed food.
As a lot of people on this thread have said, someone has to be on the lower centiles, it's just as normal as being on any other centile, adults aren't all the same size are they?!
I, like the others am worried about the comment made by your paed about him being weakend for life . I have to say my paed has been very good, we actually asked him that very question 'will ds be affected in any way by this slow weight gain later in life' and he answered 'no, not at all'. I believe that the baby would have to be severly malnourished and particularily in the forst 8 weeks of it's life for it to have any affect later on. This is clearly not the case with your lo!
It sounds like the switch feeding is doing an excellent job. You are doing so well, it takes a lot of time and effort to do what you are doing.
Our paediatrician did blood tests and took stoll samples from ds 'just to rule anything out' but atated he didn't expect anything back from the tests as he could see that ds was happy and healthy even if he was on the small side. Of course nothing came back from the tests and that put our minds at rest that nothing else was causing it. For that reason it might be worth getting these tests done if you haven't had them done already?
I'm sure everything will be fine, check out my ds on my profile, he's small but perfectly formed and full of energy, I can't keep up with him!