RELATIONSHIP BETWEEN CHANGE IN AMNIOTIC-FLUID INDEX AND VOLUME OF FLUID REMOVED AT AMNIOREDUCTION

Objective: To determine the relationship between the change in amnioti c fluid index (AFI) and the volume of fluid removed at amnioreduction. Methods: In a prospective study of 20 twin and 19 singleton pregnanci es undergoing amnioreduction for severe polyhydramnios, AFI was measur ed immediately before and after the procedure and was correlated with the volume of fluid withdrawn. Results: A significant linear relations hip was found between AFI change and the volume drained in all pregnan cies (Y = -4.2X; R-2 = 0.49; P = .002). This relationship was similar in singleton and twin pregnancies. However, there was a significant ab solute difference in AFI change between singleton and twin pregnancies of 7.9 cm (95% confidence interval 0.41, 15.2; P = .04). Conclusion: These findings support the use of the four-quadrant AFI as a semiquant itative index of amniotic fluid volume. This relationship can be used to predict the drainage volume required to achieve a target AFI with a mnioreduction and thus avoid repeated AFI measurements during the proc edure itself. (C) 1997 by The American College of Obstetricians and Gy necologists.