Gallagher P, Fagan C J, Bedi D G, Winsett M Z, Reyes R N
Department of Radiology, University of Texas Medical Branch, Galveston 77550.
AJR Am J Roentgenol. 1987 Nov;149(5):1013-5. doi: 10.2214/ajr.149.5.1013.
Sixty-three (5%) of 1239 women studied by sonography during the second trimester of their pregnancies had a diagnosis of placenta previa. Follow-up was available for 51 of the 63 patients; in three of these, the original diagnosis was complete placenta previa, and in the other 48, the first diagnosis was partial or marginal placenta previa. At term, placenta previa was seen in only four patients for an overall frequency of 0.3% (4/1227). In all three of the patients with complete placenta previa, the condition persisted from the second trimester to term; previa persisted in only one of 48 patients with marginal/partial previa. Because of the infrequent persistence of marginal or partial placenta previa to term, we recommend using the term "potential placenta previa" in the second trimester, with follow-up sonography indicated only for vaginal bleeding.
在孕期中期接受超声检查的1239名女性中，有63名（5%）被诊断为前置胎盘。63例患者中有51例得到了随访；其中3例最初诊断为完全性前置胎盘，另外48例最初诊断为部分性或边缘性前置胎盘。足月时，仅4例患者被发现有前置胎盘，总体发生率为0.3%（4/1227）。在所有3例完全性前置胎盘患者中，该情况从孕中期持续至足月；48例边缘性/部分性前置胎盘患者中只有1例前置胎盘情况持续存在。由于边缘性或部分性前置胎盘持续至足月的情况罕见，我们建议在孕中期使用“潜在性前置胎盘”这一术语，仅在出现阴道出血时进行超声随访检查。
