"It's with a deep sense of regret, a deep sense of sorrow that practices of the past have caused ongoing pain, suffering and grief to these women, these brave women in Newcastle [New South Wales] but also women around Australia," said Martin Laverty, chief executive of Catholic Health Australia.
The Maitland-Newcastle Diocese and the Singleton and North Sydney Sisters of Mercy also are issuing apologies.
At least 150,000 women -- mostly young, unwed mothers -- are believed to have lost their babies, taken against their will by churches and adoption agencies for placement in "better" homes from the 1950s though the '70s, the Australian Broadcasting Corp. reports.
The Maitland-Newcastle Diocese and the Singleton and North Sydney Sisters of Mercy will also issue apologies.
Juliette Clough told ABC how she was forced to surrender her baby in 1970, when she was 16.
"My ankles were strapped to the bed, they were in stirrups, and I was gassed ... and they just snatched away the baby," she said. "You weren't allowed to see him or touch him, anything like that, or hold him and it was just like a piece of my soul had died. And it's still dead."