(St. Paul, MN)  —  Close to two-thirds of Minnesota mothers say they took unpaid leave after giving birth.  A state survey released yesterday by the Department of Health also indicated that infant care is the most difficult to find because most child-care center don’t accept infants younger that six weeks.  The moms who took part in the poll say child care is extremely expensive.  Minnesota ranks fourth in the country among states with the most costly infant care.