The policy solution is:
- A per-child negative income tax sufficient to cover the risk/impact of employer discrimination.
- Give mothers and fathers equal leave.
- Limit the compulsory work week to 50 hours for salaried (or overtime hourly) employees.
- Penalties for violating the above sufficient to convince lawyers to take the case on a speculative basis if the client has a legitimate case.
That balances out the differences between genders and parents/non-parents sufficiently that anyone with sense wouldn't take the risk.