Gramellini D, Piantelli G, Di Marino O, Avanzini A, Vadora E
Department of Obstetrics and Gynecology, University of Parma, Italy.
Clin Exp Obstet Gynecol. 1997;24(2):70-3.
We studied the relationship between the ultrasonographically measurable variations in the amniotic fluid index (AFI) and actual changes in the amniotic fluid volume induced by three differing invasive procedures: genetic amniocentesis, amnioinfusion and amnioreduction. We examined 50 patients, all between the 15th and 34th weeks of pregnancy, subdivided into three groups. The first group consisted of 33 women who underwent genetic amniocentesis, the second was of 11 patients submitted to amnioinfusion for oligohydramnios (AFI < 5 cm), and the third was composed of 6 patients affected by hydramnios (AFI > 20 cm) and treated with amnioreduction. In all cases AFI was measured before and after the invasive procedures and their variations (delta AFI) were correlated to the actual quantities of liquid infused or extracted. All the procedures gave rise to statistically significant AFI changes. After genetic amniocentesis, the mean change was from 12.0 to 10.9 cm (p < 0.005), after amnioinfusion from 3.1 to 10.6 cm (p < 0.0001) and after amnioreduction from 33.1 to 22.0 cm. (p < 0.005). However, a significant linear correlation between delta AFI and the fluid volume variations actually induced was found for amnioinfusion (y = 0.236537 + 0.031465x; R2 = 44.4%; p < 0.05) and for amnioreduction (y = -0.0584294 + 0.012008x; R2 = 89.8%. p < 0.00001). Only for amnioreduction is it possible, as proved by a multiple regression analysis, to improve the predictability of delta AFI, taking into consideration together with the quantity of fluid aspirated, the value of the preprocedure AFI (R2 = 92%; p < 0.05).
我们研究了超声测量的羊水指数（AFI）变化与三种不同侵入性操作（基因羊膜穿刺术、羊水灌注和羊水减量）所引起的实际羊水量变化之间的关系。我们检查了50名患者，均处于妊娠第15至34周，分为三组。第一组由33名接受基因羊膜穿刺术的女性组成，第二组是11名因羊水过少（AFI < 5 cm）接受羊水灌注的患者，第三组由6名羊水过多（AFI > 20 cm）并接受羊水减量治疗的患者组成。在所有病例中，均在侵入性操作前后测量AFI，并将其变化量（ΔAFI）与实际注入或抽出的液体量相关联。所有操作均导致AFI出现具有统计学意义的变化。基因羊膜穿刺术后，平均变化从12.0 cm降至10.9 cm（p < 0.005），羊水灌注后从3.1 cm升至10.6 cm（p < 0.0001），羊水减量后从33.1 cm降至22.0 cm（p < 0.005）。然而，对于羊水灌注（y = 0.236537 + 0.031465x；R2 = 44.4%；p < 0.05）和羊水减量（y = -0.0584294 + 0.012008x；R2 = 89.8%，p < 0.00001），发现ΔAFI与实际引起的液体量变化之间存在显著的线性相关性。多元回归分析证明，仅对于羊水减量，在考虑抽出的液体量的同时，结合操作前AFI的值，可以提高ΔAFI的预测能力（R2 = 92%；p < 0.05）。
