I saw the midwife today and she gave me my MATB1. She told me to keep a copy in case work loose it because they are not allowed to reissue the form.
Might be different near you though . . .
BUT on the plus side, you don't have to submit your MATB1 as prove of pregnancy, you can submit anything signed by a midwife or dr with your due date on, including a scan report.