It's a moment that can be stressful and worrying for parents - and not one that every parent necessarily wants to share.
However award-winning journalist, Waleed Aly, has touched hearts around the nation as he opened up on-air about his son's autism diagnosis and his feeling of relief and empowerment upon hearing the news.
"I didn't worry, it didn't hit me in the face," the 40-year-old TV host revealed on The Project after a segment about the Learning for Life autism centre, "it actually explained a lot of things and it opened up doors."
Aly and his wife Dr Susan Carland, were told their son Zayn, now 11, had autism in 2011 and it helped him completely adapt his way of parenting.
"What happens is you've gotta try and re-orientate everything so that you're communicating with the kid in a way that actually works with the way their brain works", he continued.
"And when you do that and you get those moments where a door opens... it's unbelievable and your heart just leaps."
Aly went on to explain that while the diagnosis was a positive outcome, he does still worry about aspects of his son's future.
"The thing that's really scary about it, is you don't know what their ceiling is - so all the things you would normally take for granted, like when they have a career or get married or whatever, you're just facing an unknown. You don't know if those things will ever be possible," he said.
"When you see something that you don't know is possible happen, it changes your world. It's really powerful."
Reactions to Aly's comments on social media have been overwhelmingly positive and have sparked an important conversation about parenting children with special needs:
"As a fellow Autism dad, well said and those breakthroughs are very special moments," wrote one father.
"Thank you for shedding some light on parenting children who have additional needs ♥️ you're amazing!"
"When I got the diagnosis for my son,it was a great moment for me as well, I now knew there was a reason for some behaviours and there was support out there for our family. My son is now working part time and driving and independent mainly and absolutely wonderful."
"I was never as fortunate to have a parent that tried to understand autism like Waleed does. You have a very lucky boy."
Notoriously private about his family and home life, Aly first mentioned he was "the father of an autistic son" in an opinion piece about the anti-vaccination movement for the Sydney Morning Herald in 2015.
He went on to give an interview to TV Week in 2016 where he explained Zayn's diagnosis was a "major thing" for the family, but "because of the early diagnosis, he was able to get the support he needed. He's just coming on in leaps and bounds."
Aly and Carland also share a 15-year-old daughter, Aisha.
According to Autism Spectrum Australia (Aspect), around 1 in 70 Australians are on the autism spectrum - which is an estimated 40 per cent increase since 2014.
"Autism is not necessarily on the rise in Australia," said Aspect CEO, Adrian Ford last year. "We are likely getting better at recognising and diagnosing autism in people of all ages.
"This is really good news, with research highlighting the importance of early diagnosis and intervention for children with autism and their families."
As more high-profile Australians share their personal stories about autism, the greater the awareness and less stigma there is about the condition.