The importance of good practice in preimplantation genetic screening: critical viewpoints.

ger association between prenatal depressive symptoms and the risk of preterm delivery. With regard to the subtypes of preterm delivery, unfortunately, we did not have such information for that study. However, as with the potential misclassification of depressive symptoms, the effect of potential misclassification of outcomes (i.e. assuming that depression during pregnancy is only related to certain subtype(s) of preterm delivery) is to attenuate the observed association. In other words, had we only included the subtypes that are associated with depressive symptoms during pregnancy, the observed association would have been stronger.