Benji was born at 25 weeks and weighing 550g. Today the micropreemie is about to finish kindy.

For Sydney mum Hazel Castelletto the arrival of her son Benji was a miracle long before he was born.

After years of struggling with endometriosis and believing she might never fall pregnant, Castelletto conceived naturally just as she and her partner Johnny were preparing to explore IVF.

But what began as an unexpected blessing soon became a fight for survival when a life-threatening pregnancy complication forced Benji to enter the world at just 25 weeks, weighing a tiny 550g.

After six months in neonatal intensive care, Benji defied the odds to make it home.

Now six years old, he is thriving and his family is turning their gratitude into action, helping give other premature babies the same chance at life.

Castelletto, now 43, from Sydney, NSW, had long faced uncertainty about whether she would ever become a mother.

She suffered from endometriosis, a chronic condition in which tissue similar to the lining of the uterus grows outside it, often causing severe pain and difficulties falling pregnant.

“I didn’t actually think I was going to fall pregnant,” Castelletto said.

But after meeting her partner, Johnny, she knew she wanted to start a family with him.

In 2019, before they had even started IVF treatment, Castelletto fell pregnant naturally and she still remembers the surreal moment her doctor called with the news.

“It was the 13th of December. It was Johnny’s birthday and I was going to my work Christmas party,” Castelletto said.

“I was in tears and disbelief. I had to ask myself, ‘Have I heard correctly?’

“It was surreal that I didn’t have to actually go through IVF and I thought this was a miracle. This was really, really a miracle.”

Castelletto had already been diagnosed with high blood pressure before falling pregnant, so she was taking medication to manage the condition and aspirin daily.