"For randomized controlled trials of treatments, it is essential to have a clear classification of pregnancy loss type for both fetal and very early loss events. In addition, there is a strong argument for mandatory karyotyping of all pregnancy losses to exclude a lethal trisomy karyotype or triploidy. This is because, irrespective of treatment intervention, pregnancy loss has occurred and may have been described as a ‘false’ treatment failure. Recent papers testify to the high rate of abnormal chromosome type when pregnancy loss has occurred (Bricker and Farquharson, 2002; Levine et al., 2002; Stephenson et al., 2002; Philip et al., 2003; Morikawa et al., 2004)."