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Vainio M, Kujansuu E, Iso-Mustajärvi M, Mäenpää J.Vainio M, et al.BJOG. 2002 Feb;109(2):161-7. doi: 10.1111/j.1471-0528.2002.01046.x.BJOG. 2002.PMID: 11888098Clinical Trial.