Amniotic fluid distribution in predicting perinatal outcome in patients with ruptured membranes

Objective: To determine if amniotic fluid distribution predicts perinatal outcome in women with spontaneously ruptured membranes. Methods: Patients presenting for labor and delivery with spontaneously ruptured membranes had amniotic fluid indices determined upon admission. Those with greater than 50% of their amniotic fluid in the upper quadrants were placed in the upper-greater group and those with greater than 50% in the lower quadrants were placed in the lower-greater group. The groups were compared with respect to meconium staining, 1- or 5-minute Apgar scores below 7, persistent variable or late decelerations, umbilical arterial or venous pH below 7.20, cesarean for non-reassuring fetal heart rate monitoring, and neonatal intensive care unit admissions. Results: One hundred women were studied, 60 in the upper-greater group and 40 in the lower-greater group. Significant differences between upper-greater and lower-greater distributions were noted in meconium staining (28.3% compared with 0%, P < .001), 1-minute Apgar score below 7 (16.7% compared with 2.5%, P < .027), variable decelerations (63.3% compared with 25.0%, P < .001), late decelerations (23.3% compared with 0%, P < .001), and cesarean for non-reassuring fetal heart tracing (11.6% compared with 0%, P < .025). The negative predictive values for all of the variables studied were in the range 92.5–100%, with the exception of variable decelerations (75%). Conclusion: Amniotic fluid distribution predicts perinatal outcome in patients with ruptured membranes. This test’s high negative predictive value indicates its potential as a valuable screening tool. These results may provide additional guidance in defining the intrapartum management of patients presenting with ruptured membranes.