Federal Opposition Leader Malcolm Turnbull and his wife Lucy have donated $25,000 for research to help premature babies, an issue close to their hearts.

The funding was announced in Sydney on Thursday at an event for the Bonnie Babes Foundation, which provides counselling to mothers and families affected by miscarriage, stillbirth and premature birth.

The family's $25,000 donation will fund research into retinopathy, the major cause of blindness in premature babies.

Ms Turnbull said eyesight and breathing problems were two critical issues for premature babies and that she and her husband were happy to support the foundation.

"I think getting money for research is always a challenging task for small foundations, as Bonnie Babes is," she said.

The Turnbull's daughter Daisy was born prematurely in 1985.

"I went through that experience and if I had had access to the Bonnie Babes counsellors and helpers in those early days I believe that my experience would have been much less traumatic."