Is her head too big or too small?
The only information I know of relating head circumference to autism involves "macrocephaly," or abnormally large head circumference. Something like 20% of children with autism have abnormally large head circumference. More recently, research suggests that children with ASD have normal head circumference at birth, then undergo an abnormal head growth spurt around 6-9 months.
However, this information can NOT be used to predict whether a child will have autism or not, as head growth varies from child to child and not all kids with big heads go on to have autism. They are hopeful that someday they will be able to come up with a physical, biological, or genetic indicator that can diagnose autism before the behavioral signs start to show up at a later age.
BUT. They haven't. The most they can possibly say is that if your child happens to have abnormally large head circumference, be on the lookout for early warning signs.
If her head is too small, I don't really understand why he would even bring up this possibility. Actually, I don't see why he would bring up the possibility anyway.
Hope that helps!
You'd have to take her to a specialist to get a diagnosis. 9 months seems a little young to make a diagnosis unless she's like having seizures or other problems.
Crawling at 9 months is great. Waving goodbye and clapping also amazing!! Looking at you when you call her name? Also amazing! Signs for autism would be not responding to her name, not looking at you in the eye, and a whole bunch of other things (arm flapping and toe walking for the older kids who can walk can be a sign though not proof).
My daughter is tall and big boned (yeah, on the heavier side). Her head is large! And yet, she was born 3 weeks early (came out at 7 1/2 pounds 3 weeks early) and started growing like she was a plant and I was giving her fertilizer or something like that. But she missed all her milestones. Pediatrician didnt' seem to care too much because she was healthy as an ox and growing and large and showing no health problems aside from hitting her milestones (she didn't sit up till 7 1/2 month which is on the later end but not to cause too much worry... didn't crawl until 12 months, didn't walk until 16 1/2 months). All her milestones were at the way late limits... and then the talking... she didnt' say her first word until maybe 27 months of age. And that was after 2 1/2 months of therapy. She didn't babble much as a young baby either. Her eye contact with us parents was great but with other people was non-existant (that was before therapy). She did not respond to her name until she was about 2 1/2. That was after several months of sensory integration therapy. And also her receptive language was late to kick in. All she heard was blah blah blah... she couldn't differentiate any words, including her name. Until about 2 1/2. Another thing to look for is pointing. Kids will start to point at things between 12 and 15 months of age. If you point at something, around 15 months of age they should be looking at what you are pointing at. My daughter still has problems with this at 3 1/2... and she didn't understand pointing at all until she was well over 2 1/2, probably closer to 3. She still has difficulty with it. It's something about the skill being "shared attention".
Honestly I don't see how a pediatrician would say a child has autism because their head is on the smaller side or rule out autism because a child is growing so well and their head is huge. WHat I figured out is that regular pediatricians are great for figuring out ear infections, strep throat, flu, colds, bronchitis, whatever other "ill" things there are. But screening for developmental things? I really don't think they have been trained in that.
Since the girl is a preemie though... making sure she does hit all her milestones and keeping track of them is important. You could google signs for autism and see what comes up. But really, not sure I've heard of anyone screening for autism at 9 months of age. I think it is typically done at 18 months and 24 months checkups.