The change in the pronunciation of 'midwifery' seems to have occurred over the past 20 years, Fred. In the print version of the OED (1980s) the two pronunciations offered were wiff and wife. The more recent, obviously, online OED offers only wiff; however, there are still two versions, as the stress may be put on the first OR second syllable, thus MIDwiffery or midWIFFery. Only Americans nowadays, it seems, still have midWIFEry.
Re schism, both print and online OED versions still offer sizm or skizm, so use whichever appeals to you. I recall an American comedian suggesting that we Brits said shedule rather than skedule because that is how we were taught to say it in shool!