Re: Clinical significance of first-trimester chorionic bumps: A matched case-control study. Y. Sana, A. Appiah, A. Davison, K. H. Nicolaides, J. Johns and J. A. Ross. Ultrasound Obstet Gynecol 2013; 42: 585-589

摘要

In this issue of the Journal, D'Antonio et al. tackle the difficult task of pulling together 23 very different papers into a systematic review. Some studies in the placenta accreta literature involve multiple institutions and interpreters and/or have no consistent criteria used across all examinations. In other studies, operators proceeded to magnetic resonance imaging or color Doppler only if the grayscale findings were suspicious, introducing selection bias. The authors of this review selected 23 out of a total of 88 possible papers. The primary criteria were cases over five in number and non-review in design. Among those 23 papers, there was still significant heterogeneity: 10 were retrospective, nine relied at least in part on reports of surgeons on the difficulty of removal of the placenta, rather than solely pathological examination of a removed uterus, three included all patients with placenta previa with or without previous surgery and 11 did not employ color Doppler. Results were so variable that a statistical adjustment had to be made for heterogeneity.