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Timmermans A, Veersema S, van Kerkvoorde TC, van der Voet LF, Opmeer BC, Bongers MY, Mol BW.Timmermans A, et al. Among authors: opmeer bc.BJOG. 2009 Sep;116(10):1391-5. doi: 10.1111/j.1471-0528.2009.02234.x.BJOG. 2009.PMID: 19691631Clinical Trial.