Phelan J P, Ahn M O, Smith C V, Rutherford S E, Anderson E
Department of Obstetrics and Gynecology, University of Southern California School of Medicine.
J Reprod Med. 1987 Aug;32(8):601-4.
Amniotic fluid volume assessment has become an important part of antepartum fetal surveillance. The amniotic fluid index (AFI), or four-quadrant technique, has been suggested for this purpose. While previous reports have outlined this technique and correlated the results with pregnancy outcome, none have reviewed the changes in AFI throughout pregnancy. We studied AFI changes from 11 through 43 weeks' gestation. As part of the entry criteria, only patients with good dates were evaluated. The AFI was determined by the summation of the vertical diameter of the largest pocket in each of the four quadrants. All amniotic fluid studies were conducted using real-time linear array B-scan. During the study period, 197 patients with good dates confirmed clinically and sonographically underwent 262 AFI assessments. From 11 to 26 weeks the AFI rose progressively. Thereafter until term, the AFI remained approximately 16.2 +/- 5.3 cm. After 38 weeks the AFI appeared to gradually decline. Data obtained from this study population corroborate previously defined normal amniotic fluid volumes. These results also suggest that serial measurements of the AFI may be an effective means of assessing fetal status throughout pregnancy.
羊水容量评估已成为产前胎儿监护的重要组成部分。为此有人提出了羊水指数（AFI），即四象限法。虽然此前的报告已概述了该方法，并将结果与妊娠结局相关联，但尚无报告对整个孕期AFI的变化进行综述。我们研究了妊娠11周至43周期间AFI的变化。作为纳入标准的一部分，仅对预产期明确的患者进行评估。AFI通过四个象限中每个象限最大羊水池垂直深度之和来确定。所有羊水检查均使用实时线性阵列B超进行。在研究期间，197例临床和超声检查均证实预产期明确的患者接受了262次AFI评估。从11周到26周，AFI逐渐上升。此后直至足月，AFI维持在约16.2±5.3厘米。38周后AFI似乎逐渐下降。从该研究人群获得的数据证实了先前定义的正常羊水量。这些结果还表明，连续测量AFI可能是评估整个孕期胎儿状况的有效方法。
