Critically Ill Obstetrics Patients and Newborn Visitation

What is your experience with postpartum patients and infant visitation? We are having two issues in my ICU right now, first is that we're having difficulty getting the mother-baby nurses to let the stable infants visit their moms in ICU. Second, once the mother is discharged from ICU, their policy prohibits her from returning to the post-partum unit - she must go to a med/surg unit (and therefore cannot room-in with the infant). This is especially distressful for 1st time moms since they usually cannot learn infant care prior to infant discharge. The rational for this policy is that after ICU, these patients are "dirty." To clarify, we keep the moms on the neurosurgical ICU part (the "clean" unit). Is there any research backing this up? Thanks!