The Government is being urged to offer more support to working parents after a study showed a low take-up of shared parental leave.
Just one in 20 new fathers and 8% of new mothers have taken up the shared arrangements since they were introduced in April 2015, said the Chartered Institute of Personnel and Development (CIPD).
Only one organisation in five had received requests from male workers to take up shared leave since it was launched, a survey of 1,000 human resources staff also found.
The lack of free childcare for under-twos could be having a negative impact on women returning to work after maternity leave, the report suggested.
Rachel Suff, of the CIPD, said: "Shared Parental Leave was a milestone for gender equality when it was introduced last year.
"The intentions were right and, on paper, it gives new parents much more choice and flexibility about taking leave to look after a new baby, particularly if the mother is the higher earner and if dads want to play a bigger role in their child's early life.
"However, the complexity of the rules and the financial gap between statutory maternity pay and statutory shared parental pay in the early weeks are clearly outweighing these positives in reality for many.
"Government needs to look at what steps can be taken to ensure SPL can bring a step change on the ground in the UK."