Give them the option- either provide birth control for women under your health insurance plan or provide full paid maternity leave.
Why is this important?
The Family and Medical Leave Act of 1993 allows for unpaid leave up to 12 weeks. An amendment could integrate this with the Affordable care act allowing for a choice between supporting one of two programs. If a business or religious institution opts out of providing birth control through their medical coverage they should provide full paid maternity leave.