Relationship of Spectrophotometric Analysis of Amniotic Fluid to the Onset of Spontaneous Labor

Amniotic fluid optical density readings of .000 were related to the onset of spontaneous labor. There were 272 amniocenteses performed upon 160 patients, 84 of whom had one or more .000 readings. EDC and .000 Δ optical density had a closer relationship to the onset of labor than either EDC or birth weight alone. A group correlation between .000 density and the time of onset of labor was noted. Three of 5 patients went into labor within 2 weeks, and 3 of 4 patients within 4 weeks of the reading. The rate of error in individual patients indicates that this test alone is not sufficient and should be supplemented by other findings.