Every parent of a young child worries about their child’s development. But some milestones are easier to instinctively track or evaluate than others. And once a missed milestone is intuited or spotted, it’s not always easy for parents to know what to do; it can be disconcerting to experience signals that aren’t definitive.

In this article, we explore some of the early signs of autism spectrum disorder, to aid parents who might be wondering whether to seek the help of a professional. It’s important to remember there’s no downside to consulting a professional, even if you’ve only sensed one of these signs; there’s only an upside, as early intervention is absolutely critical to helping a child on the autism spectrum adapt and thrive.

What is autism?

Briefly, autism is a “neurodevelopment disorder” along a spectrum, which means children who do receive a diagnosis can exhibit symptoms that are severe or very subtle. The disorder affects social and cognitive development, and can result in difficulty with communication and repetitive or seemingly ritualistic behaviors. It is four times more prevalent in boys than girls (though recent research has suggested girls may simply be better at masking early signs of autism than boys). And babies who were born premature or at a very low birth weight are especially susceptible to developmental delays that could herald autism.

What does ‘early’ mean?

Signs of autism can be seen as early as six or nine months. You can keep an eye on the classic developmental milestones to get a sense whether your child’s development is following the norm, but your pediatrician should also be doing regular milestone checks at approximately 9, 12, and 24 months. (If they don’t, you can request such checks.)

Early signs of autism

If at six to nine months, babies are not smiling back at caretakers or engaging with them with sounds and expressions by this age, it may be cause for concern. By 12 months, babies should be babbling and expressing preferences by pointing or reaching. By age two, they should be able to string two or more words together into a coherent phrase. If your baby is not meeting those basic milestones, it’s important to point these out to your pediatrician.

Below is a list of other early warning signs to keep an eye out for, per the National Autism Association. A child on the spectrum, between the ages 6 to 30 months, might also:

• Not respond to their name (the child may appear deaf)
• Not point at objects or things of interest, or demonstrate interest
• Not play “pretend” games (e.g. can’t ‘hop like a bunny’)
• Avoid eye contact
• Want to be alone
• Have difficulty understanding, or showing understanding, other people’s feelings or their own
• Have no speech or delayed speech
• Repeat words or phrases over and over (echolalia)
• Give unrelated answers to questions
• Get upset by minor changes
• Have obsessive interests
• Flap their hands, rock their body, or spin in circles
• Have unusual reactions (over or under-sensitivity) to the way things sound, smell, taste, look, or feel
• Have little to no social skills
• Avoid or resist physical contact
• Demonstrate little safety or danger awareness
• Reverse pronouns (e.g., says “you” instead of “I”)

When to be concerned

Because some of these red flags are subtle, it can be difficult to know when to act. That said, a helpful screening tool called the M-CHAT is available online for parents to self-screen children aged 16 to 30 months. This tool is not intended to allow parents to make an autism spectrum diagnosis, but rather to evaluate whether missing milestones or troubling behaviors warrant a visit to a qualified professional. (Results can be printed and taken to a doctor for review.)

A developmental delay isn’t a diagnosis, much less a life-sentence; but nor should it be ignored. It bears repeating: There’s no downside to consulting a professional — a pediatrician, child psychologist, speech therapist, or other specialist — if you are worried over a developmental delay, and only an upside for your child.