Employers have begun using a company that analyzes employees health based on medical benefit claims and other data. Company says for now it only tells the employer or client they might have several pregnant women/employees for example. Employees wind up "opting in" to be monitored by agreeing to things like a doctor search on their benefit plan. The company is called Castlight.
http://time.com/4228579/women-work-pregnancy-workplace-employment-data/
http://time.com/4228579/women-work-pregnancy-workplace-employment-data/