"Phoenix was such an easy pregnancy, and I got pregnant really, really quick - it was very simple," Sursok said.
"When we decided to have a second child, I got pregnant really fast again - and we lost that baby in the doctor's office.
"It was pretty far into my pregnancy, so it was quite shocking. When things like that happen, you never think it's going to happen to you.
"But they're so common, and we don't talk about it. And then I had another miscarriage before Lennon, so two back to back.
"Women don't speak about the things that they're going through. We feel so isolated and feel so alone."
Changing family life
"Nobody talks about this, but the first year of having a baby is so blissful and so hard - and it's so hard on your marriage too," Sursok said.
"You're like passing ships. You never really have date night.
"Our first date night was three weeks after the baby was born, and he fell asleep at the table.
"At the end of the day, we love each other so much and respect each other so much - and we have each other's back - and if you have that, you can traverse the waters when you bring another human into the world."
Struggles with body image
The actress recently opened up about being bullied as a child about her weight on Instagram - having once weighed 95kg when she was 14 years old.
"I've learned throughout my life and journey that unhappiness is the fastest pipeline to hate," Sursok said.
"When people aren't happy, they shame other people and bully.
"For me, I look back, and I realise it was never really about me. It was about them. And people who put other people down, it's because you're showing something that they don't like about themselves.
"I've been through extensive therapy, because for me I still feel like that overweight girl. And I don't really ever feel like I'm good enough.
"It's important to talk about, and I think a lot of people struggle with bullying. And for me, if my platform can help just one person, then my job is done."
This article originally appeared on 7news.com.au