Currently the only way maternity leave can be postponed is in the case of a child being hospitalised.
The Irish Cancer Society is calling on the Government to change current legislation that prevents women from deferring their maternity leave while they are being treated and recovering from cancer.
The 'Leave our Leave' video campaign, which was launched at Leinster House, aims to highlight the issues facing women who are diagnosed with cancer during pregnancy.
The Maternity Protection Act 2004 states that anyone who is diagnosed with cancer or any other serious illness during pregnancy must use their maternity leave to cover their treatment.
The only way maternity leave can be postponed is in the case of a child being hospitalised.
This law currently affects around 60 women each year, according to the Irish Cancer Society.
It said the issue emerges once the person tries to pause their maternity leave while they are being treated for cancer.
Emma McGuinness, Spokesperson for the Irish Cancer Society, was diagnosed with Hodgkin's Lymphoma in the early stages of pregnancy, listen back here;