This varies immensely. I had a PhD student from Sri Lanka when I was still in Reading. She was on a University overseas studentship. She became pregnant half way through her PhD and received identical maternity leave arrangements to permanent staff with regards to her stipend (paid at the usual percentage rate for staff for thesame length of time) and the time duringwhich she suspended her course. This was based on equity with EPSRC studentship rules - they decided that the university scholarships shuold have the same rules as the research council ones.