Katz V L, Seeds J W, Albright S G, Lingley L H, Lincoln-Boyea B
Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill.
Am J Perinatol. 1991 Mar;8(2):73-6. doi: 10.1055/s-2007-999346.
Informed consent of medical procedures should include a discussion of both the risk of the procedure and the probability of the malady in question. Many centers in the United States currently recommend amniocentesis for all women with elevated levels of maternal serum alpha-fetoprotein (MSAFP) unexplained by targeted ultrasound examination. Prospective clinical data from our unit support the use of an algorithm that provides for a 90% reduction of the predicted risk of neural tube defect from MSAFP alone. The predicted risk is revised only if the ultrasound shows normal fetal cranial size and shape, normal ventricular size, normal posterior fossa anatomy, and normal spinal anatomy. Preliminary results supported this approach with no reduction in sensitivity, while substantially reducing the need for invasive testing. The additional experience reported here of 20,211 patients resulted in 451 ultrasound examinations for an elevated MSAFP, but only 54 amniocenteses. During this period, nine open neural tube defects were detected among patients with elevated MSAFP using ultrasound; none was missed. All fetuses with defects had ultrasound findings of cranial and intracranial changes first reported by Campbell. These data support the premise that, prior to amniocentesis, informed consent should include discussion of the ultrasound evaluation.
医疗程序的知情同意应包括对该程序的风险以及所讨论疾病的发生概率的探讨。美国目前有许多医疗中心建议，对于所有经针对性超声检查无法解释的母血甲胎蛋白（MSAFP）水平升高的孕妇，都应进行羊膜穿刺术。我们单位的前瞻性临床数据支持使用一种算法，该算法可使仅根据MSAFP预测的神经管缺陷风险降低90%。仅当超声显示胎儿颅骨大小和形状正常、脑室大小正常、后颅窝解剖结构正常以及脊柱解剖结构正常时，才会修正预测风险。初步结果支持这种方法，在不降低敏感性的同时，大幅减少了侵入性检查的需求。此处报告的另外20211例患者的经验显示，有451例因MSAFP升高而进行了超声检查，但仅进行了54次羊膜穿刺术。在此期间，在MSAFP升高的患者中通过超声检测到9例开放性神经管缺陷；无一漏诊。所有有缺陷的胎儿都有坎贝尔首次报告的颅骨和颅内变化的超声表现。这些数据支持这样一个前提，即在进行羊膜穿刺术之前，知情同意应包括对超声评估的讨论。
