Mamas&Papas Pro tec minimum age

[beaufies]

My 21 week old DS is outgrowing his car seat. His feet are touching the seat of the car and his head is touching the sun shade/hood at the top of his seat. He is very big for his age (91st centile weight and length), has very good head control and sits with a straight back with a little support.

He will simply not fit in another few weeks and we need to get a new one. I would like to get the Mamas & Papas Pro tec but see it is recommended from 9 mths. I believe it also states 9kg and DS was 8kg when last weighed 3 weeks ago.

My question is, what is more important - weight or age ? Would it still be suitable for DS if he is say, 5 months and 8.5kg ?

Thanks in anticipation

is it a forward facing seat? If so, he is too young to go into it at 5 months. If he is under 9kgs then he is also too light to go in it too. He needs to be at least 9kgs and able to sit unaided for a good 20/30minutes before he can face forwards - he should also be as close to 9 months as possible. It is ok for their legs to be long/bent and he should be ok until his eyeline reaches the back of the seat. The alternative is a combination seat that both rear and forward faces but is bigger and will give him more time to rear face than the infant carriers.