The survey of 1,000 parents found that 65% are unaware of the planned changes, which will allow male and female employees to split leave between them when they have a child.
A large majority (84%) stated they will not take up the offer once it is available, admitting it will change to how they use their leave when the baby is born.
Many parents who are aware of the changes are also unclear of the finer details. Nearly half (43%) believe rights will be completely equal for mothers and fathers. In reality, either the mother or primary adopter will need to give permission for the shared parental leave to be used.
One area of the changes that is popular among parents is the option to take between two and five years to raise a child. More than two-thirds (65%) of parents polled said they would take this option if their employer offered it.
Jennifer Liston-Smith, head of coaching and consultancy at My Family Care, told HR magazine the results "highlight a need to educate prospective parents about their options".
The research also suggests employers are unsure about the implications of SPL. Only 15% have a clear idea of how they will implement it. Liston-Smith added that despite this, employers are generally positive about the changes.
"We have found that the majority of companies we are working with have welcomed the idea of SPL to support their staff and family-friendly policies," she said. "It's also seen as a way of providing more talent retention choices for those women who are significant or main bread winners within families."